'Proving' an extinction...

[King of the Americas]

...how do you do that exactly?

Say I wanted to hunt something TO extinction, how could I be 'absolutely' certain I finished the job.

And if it were an illusive predator, the job may be really difficult.

If an animal 'learns' that human=death, finding them on foot would be all but impossible.

But until you could search and scour every square yard of a continent, how could you be certain you finished the job?

[Vic Vega]

I don't think you could be absolutely certain, but there must be a scientific criteria for determining that an animal is extinct.

I'm pretty sure I've read about animals that have turned up after they were thought to be extinct.

[Bikewer]

I doubt it was ever the intent of either our ancestors or our contemporaries to actually hunt some species to extinction; rather as in the case of the passenger pigeon, they just sort of arrogantly assumed that the incredible numbers of these animals were simply inexhaustible.
Perhaps extinction was deliberate in the case of the American bison, as a strategic move against native Americans.

[King of the Americas]

I don't think you could be absolutely certain, but there must be a scientific criteria for determining that an animal is extinct.

I'm pretty sure I've read about animals that have turned up after they were thought to be extinct.

EXACTLY.

Things HAVE shown back up, after thought to be extinct. That fish with 'leg' looking fins, the "Coelacanth"...

[King of the Americas]

I doubt it was ever the intent of either our ancestors or our contemporaries to actually hunt some species to extinction; rather as in the case of the passenger pigeon, they just sort of arrogantly assumed that the incredible numbers of these animals were simply inexhaustible.
Perhaps extinction was deliberate in the case of the American bison, as a strategic move against native Americans.

Didn't we 'try' to hunt wolves to extinction, here?

They 'claimed' to have hunted the Tasmanian Tiger to extinction, but there are still sightings that occur.

Isn't it probable that something(s) thought to be gone, to have found a home outside of our perception?

The strong survive, for a reason. If an animal learned that human 100% = DEATH, why couldn't they 'totally' avoid us?

[Robster, FCD]

EXACTLY.

Things HAVE shown back up, after thought to be extinct. That fish with 'leg' looking fins, the "Coelacanth"...

The coelacanth is an order of fish, much harder to get rid of than a single species.

Want to destroy a species? Eliminate its habitat, introduce a non native competitor, shoot any you see.

The first is the hardest, but also the most effective.

[Hokulele]

The strong survive, for a reason. If an animal learned that human 100% = DEATH, why couldn't they 'totally' avoid us?


Physical ability. Just ask any dodo.

[Denver]

You can't really 'prove' an animal is extinct. But you can reasonably conclude it is extinct based on all the evidence.

ETA: And from that, conclude that people who deny its extinction, are being unreasonable.

[Marduk]

EXACTLY.

Things HAVE shown back up, after thought to be extinct. That fish with 'leg' looking fins, the "Coelacanth"...


thats because Coelacanth is an order of fishes and not a species, in effect the Coelacanths from the cretaceous did become extinct then, some of them managed to survive and continued evolving into Latimeria chalumnae
http://upload.wikimedia.org/wikipedia/commons/4/4b/Coelacanth.png
these are the extinct versions
http://scienceblogs.com/pharyngula/upload/2007/03/coelacanths.jpg
A. Macropomoides orientalis, from the late Cretaceous.
B. Rhabdoderma elegans, late Carboniferous.
C. Allenypterus montanus, early Carboniferous.
once again you have posted out of ignorance K
and they are not "leg looking fins", they are lobed fins
:p

[King of the Americas]

Physical ability. Just ask any dodo.

The dodo were stupid, AND slow, and not very adept.

Hunting an illusive predator would be tougher, I think.

[King of the Americas]

thats because Coelacanth is an order of fishes and not a species, in effect the Coelacanths from the cretaceous did become extinct then, some of them managed to survive and continued evolving into Latimeria chalumnae
http://upload.wikimedia.org/wikipedia/commons/4/4b/Coelacanth.png
these are the extinct versions
http://scienceblogs.com/pharyngula/upload/2007/03/coelacanths.jpg

once again you have posted out of ignorance K
and they are not "leg looking fins", they are lobed fins
:p

Being poorly informed is quite different than being 'ignorant'.

I have no problem accepting evidence from an outside source.

[King of the Americas]

The coelacanth is an order of fish, much harder to get rid of than a single species.

Want to destroy a species? Eliminate its habitat, introduce a non native competitor, shoot any you see.

The first is the hardest, but also the most effective.

In my experience 'life prevails'... You can't ever wipe ALL of them out.

[King of the Americas]

You can't really 'prove' an animal is extinct. But you can reasonably conclude it is extinct based on all the evidence.

ETA: And from that, conclude that people who deny its extinction, are being unreasonable.

You can 'conclude' something based on unproven evidence?

And those who disagree can be found to be unreasonable?

Interesting.

[Marduk]

Being poorly informed is quite different than being 'ignorant'.

I have no problem accepting evidence from an outside source.
the fact that you were making a statement about something which you dont know anything about makes it an ignorant statement does it not, if you realised that you are poorly informed and take steps to change it then I agree, but you didn't do that did you, and you havent done that at any point in any post you have ever made, so I think my description was apt, but thanks for mentioning it and giving me another opportunity to expound on your ignorance for the amusement of others K
;)

[Marduk]

In my experience 'life prevails'... You can't ever wipe ALL of them out.

go fetch me a dodo and a t rex then,
;)

[paximperium]

go fetch me a dodo and a t rex then,
;)
Ahhhh, the ever elusive T-rex. It must be hiding with the Greys and bigfoot.

[William Parcher]

...how do you do that exactly?

But until you could search and scour every square yard of a continent, how could you be certain you finished the job?


This (http://creo.amnh.org/goals2.html) would be a good read on this topic.


Committee on Recently Extinct Organisms (American Museum of Natural History)

New Criteria for Analyzing Recent Extinctions (The results of the CREO Workshop held on May 15 and 16, 1999)


It is difficult, if not impossible, to prove that the absence of a species (in recent times) is equivalent to its extinction. The best approach is to compile all available evidence that a species is absent, and then decide when the weight of that evidence is sufficient to assume that extinction has occurred. In order to evaluate the evidence in a rigorous and consistent manner, a system of criteria for analyzing the evidence must be developed.

[Marduk]

Ahhhh, the ever elusive T-rex. It must be hiding with the Greys and bigfoot.

probably holding out in a henhouse then
;)

[linusrichard]

You can 'conclude' something based on unproven evidence?
Of course. If you want to come to a conclusion, it should be based on evidence. And "unproven" evidence (in the sense of not proven beyond all doubt) is the only kind of evidence there is.

And those who disagree can be found to be unreasonable?
That's what "beyond a reasonable doubt" means - to the point where any doubt would be unreasonable. Do you consider the flat-earthers, the young-earth creationists, and the 9/11 truthers to be "reasonable"?

Interesting.
I guess.

[makaya325]

...how do you do that exactly?

Say I wanted to hunt something TO extinction, how could I be 'absolutely' certain I finished the job.

And if it were an illusive predator, the job may be really difficult.

If an animal 'learns' that human=death, finding them on foot would be all but impossible.

But until you could search and scour every square yard of a continent, how could you be certain you finished the job?

Well, you can rule out a species current existence if:

1. There is no mark on the food chain from them

2. No bodies

3. No remains

4. No photos

kind of like bigfoot. :rolleyes:

[Dogdoctor]

It's proving a negative. You can't do it easily or with 100% certainty but then if they are that close to extinction it's usually just a matter of time. First you need to have a range/distribution of habitat for the species established so you know where you have to look. Then you need to go look. After numerous years of no sightings then you can assume it is probably extinct. The smaller the range the easier to call them extinct. As long as there are no further sightings or evidence of their existence then they are functionally extinct.

[Robster, FCD]

In my experience 'life prevails'... You can't ever wipe ALL of them out.

All life, no. But a specific species?

The Yangtze river is a polluted cesspool, and was once home to the Yangtze river dolphin. It couldn't migrate to another river system, so it is stuck in one regional habitat. The population of dolphins died off to the point that only a single one has been observed in the river in the last few years, and since you need two to tango...

[makaya325]

...how do you do that exactly?

Say I wanted to hunt something TO extinction, how could I be 'absolutely' certain I finished the job.

And if it were an illusive predator, the job may be really difficult.

If an animal 'learns' that human=death, finding them on foot would be all but impossible.

But until you could search and scour every square yard of a continent, how could you be certain you finished the job?

Ask yourself this: How do we know Trex is extinct? Simple: Something of that size would be found daily instead of never.

[TriangleMan]

Can't prove a negative and some species will surprise you. Here's an example of a bird thought to be extinct for over 300 years, who's habitat was only 50 sq km. Reasonable for people to think that it was extinct. Ironically it was probably the only reason why it survived -- we weren't looking for it (settlers were using them for food).

http://en.wikipedia.org/wiki/Cahow

[King of the Americas]

go fetch me a dodo and a t rex then,
;)

'I' was around for neither of those...

I said in MY experience...

...'life prevails'.

Ants..they are winning. I fight them back, eliminating large obvious mounds, but I fear they've 'learned' to keep the above mounds small and scattered...

I keeping seeing ants, I doubt seriously one could eliminate them completely.

We've been trying to 'eliminate' the wild hogs from this area, to no avail, for years. (*These are domestic hogs that escaped or were turn loose, that are not indigenous to the area, and literally wreck the country side.)

We call, hunt, track, and trap but they're still out there, smart, mobile, and elusive.

And they're just "pigs".

[King of the Americas]

This (http://creo.amnh.org/goals2.html) would be a good read on this topic.


Committee on Recently Extinct Organisms (American Museum of Natural History)

New Criteria for Analyzing Recent Extinctions (The results of the CREO Workshop held on May 15 and 16, 1999)

Better excerpt:

"Prototype Extinction Criteria

A species extinction within recent times can be considered resolved only if it meets these Basic Criteria:

1) the species name and status are valid taxonomically.

2) the effective extinction date or EED (the last known date or time-interval in which the species was observed or collected, which provides a minimum date of loss for the taxon) can be positively confirmed as being later than AD 1500 either:

a) because a living specimen has been collected or seen by a reliable source since that date (observation of the species without collected specimens was not classified as acceptable evidence for the study made on fishes); or

b) because fossil remains of the target taxon have been either:

i) radiocarbon-dated, or

ii) found in close association with those of an alien species known to have been introduced post AD 1500.

3) No individuals have been observed reliably in at least the past 50 years."

[Denver]

'I' was around for neither of those...

I said in MY experience...

...'life prevails'.

Ants..they are winning. I fight them back, eliminating large obvious mounds, but I fear they've 'learned' to keep the above mounds small and scattered...

I keeping seeing ants, I doubt seriously one could eliminate them completely.

We've been trying to 'eliminate' the wild hogs from this area, to no avail, for years. (*These are domestic hogs that escaped or were turn loose, that are not indigenous to the area, and literally wreck the country side.)

We call, hunt, track, and trap but they're still out there, smart, mobile, and elusive.

And they're just "pigs".

Sounds like the evidence for the existence of ants and hogs is very good, and so it would be reasonable to conclude that ants and hogs are not extinct.

Using some commonly accepted standard of evidence for your conclusion (people see them all the time; they have been captured and put on display, both in museums and in zoos; zoologists and biologists agree on their existence; there is clear and abundant video evidence; etc) is what makes the conclusion reasonable.

[King of the Americas]

Of course. If you want to come to a conclusion, it should be based on evidence. And "unproven" evidence (in the sense of not proven beyond all doubt) is the only kind of evidence there is.


That's what "beyond a reasonable doubt" means - to the point where any doubt would be unreasonable. Do you consider the flat-earthers, the young-earth creationists, and the 9/11 truthers to be "reasonable"?


I guess.

Oh, it is just that earlier I was condemned for drawing conclusions without 'scientific evidence that could be repeatedly tested'...

I'm afraid I don't know anything about the groups you mentioned. I am sure they each have their line of reasoning, not that'd I'd agree with it.

What I find interesting is the two different sets of criteria for 'conclusions' there are between the two threads I have going.

[Marduk]

We've been trying to 'eliminate' the wild hogs from this area, to no avail, for years. (*These are domestic hogs that escaped or were turn loose, that are not indigenous to the area, and literally wreck the country side.)

We call, hunt, track, and trap but they're still out there, smart, mobile, and elusive.

And they're just "pigs".

so are you saying the pigs and ants are smarter than you ?
:D

either way, if you wiped out every ants nest and every pig in a 1000 mile circle around your home they would only be extinct in your area, extinction happens most often to animals that aren't diverse contained in a limited area or who are limited to one food source. Imagine for instance, if you did kill all the pigs, how long would it be until some farmer lost a few more, if you killed all the ants, how long would it take before new ants moved into the area. In fact how long would it be before conservationists were releasing ants into the area

Pigs and ants are very succesful creatures, you could have picked a better example
:p

[King of the Americas]

Sounds like the evidence for the existence of ants and hogs is very good, and so it would be reasonable to conclude that ants and hogs are not extinct.

Using some commonly accepted standard of evidence for your conclusion (people see them all the time; they have been captured and put on display, both in museums and in zoos; zoologists and biologists agree on their existence; there is clear and abundant video evidence; etc) is what makes the conclusion reasonable.

Agreed, 'life prevails in my experience'.

I'm actively engaged in trying to wipe something out, without much success.

Those who claimed to hunt the Tasmanian Tiger to 'extinction' were wrong as well, it would seem.

[Marduk]

Those who claimed to hunt the Tasmanian Tiger to 'extinction' were wrong as well, it would seem.
thats a very bad example, the tasmanian tiger is as well documented as bigfoot in that there is no real supporting evidence, just eyewitness accounts

[King of the Americas]

so are you saying the pigs and ants are smarter than you ?
:D

either way, if you wiped out every ants nest and every pig in a 1000 mile circle around your home they would only be extinct in your area, extinction happens most often to animals that aren't diverse contained in a limited area or who are limited to one food source. Imagine for instance, if you did kill all the pigs, how long would it be until some farmer lost a few more, if you killed all the ants, how long would it take before new ants moved into the area. In fact how long would it be before conservationists were releasing ants into the area

Pigs and ants are very succesful creatures, you could have picked a better example
:p

This is MY experience...sorry it isn't more diverse. The point of the post is that proving you exterminated something, is tough if not impossible.

The dodo may well be gone, but I think it is because they weren't very adept.

Gigantopithecus existed. How intelligent and adept would they have been?

Are they limited in range, do they require a special diet?

What would happen if you eliminated their main food source, could they finds other means of survival?

[Ashles]

The strong survive, for a reason. If an animal learned that human 100% = DEATH, why couldn't they 'totally' avoid us?

Because animals don't think like humans do. The few remaining might exist in a rarely explored area and might avoid human activity wherever encountered. But they would be surviving as much by luck as by instinct to avoid humans.
They aren't thinking "We must make sure we don't get made extinct."

So we could make something extinct without any deliberate effort at all, or we could actively try to make something extinct and fail.

There are quite a lot of random factors, not least of which is, how resilient is the species?
If they are already poorly suited to the environment or have little/no predator avoidance then it's probably far easier to make something extinct than a species that is already well suited to its environment and the only factor changing is our sudden (bizzarre) decision to eradicate them.

There would be no real way to definitively prove extinction - I'm sure there is some generally accepted time without sightings that is generally accepted as indicating extinction, but obviously this would be subject to reversal if the animal was then sighted.

[Marduk]

The dodo may well be gone, but I think it is because they weren't very adept.

it was because dodos were not scared of mankind who it had never seen before and didn't realise was a predator.

Gigantopithecus existed. How intelligent and adept would they have been?

its irrelevant they werent as intelligent or adept as survival as we were because it was humanity taking over its habitat thatcaused its extinction

Are they limited in range, do they require a special diet?

they are now

What would happen if you eliminated their main food source, could they finds other means of survival?
gigantopithecus was an omnivore the same as us, you are thinking of Koalas who would bne screwed if Eucalyptus went extinct

[King of the Americas]

thats a very bad example, the tasmanian tiger is as well documented as bigfoot in that there is no real supporting evidence, just eyewitness accounts

People KEEP seeing it, so it isn't extinct.

Existence has been documented, in order to maintain that qualification, it only needs to be seen within 50 years by a reliable witness.

[Marduk]

rubbish, where do you come up with this stuff
the tasmanian tiger is extinct until proven otherwise, unreliable statements from people who do not know what they are looking at is not evidence, seems you are still failing to appreciate that fact, this is why you are continuously being proven wrong wether its this or ufos, if you can't prove what you have seen then it can't be proved that youre not a liar

evidence is something that by its very definition can be tested

I would like to think that the tassie is not extinct because I think it was a magnificent animal, but theres no solid evidence thats the case

[King of the Americas]

it was because dodos were not scared of mankind who it had never seen before and didn't realise was a predator.

Agreed.

its irrelevant they werent as intelligent or adept as survival as we were because it was humanity taking over its habitat thatcaused its extinction

But we still haven't taken over 'all' of it potential environment...

they are nowLimited yes, but they can still eat almost anything.

gigantopithecus was an omnivore the same as us, you are thinking of Koalas who would bne screwed if Eucalyptus went extinct

So, how likely is it that they are ALL gone, given their range, diet, and intelligence?

[William Parcher]

People KEEP seeing it, so it isn't extinct.

Existence has been documented, in order to maintain that qualification, it only needs to be seen within 50 years by a reliable witness.


In this instance, witness reliability cannot be tested. When it is examined, it is found to be consistently unreliable.

Here (http://forums.randi.org/showthread.php?t=132731) is a thread I started in January that is related.

Using Anecdotal Occurrence Data for Rare or Elusive Species: The Illusion of Reality and a Call for Evidentiary Standards

Anecdotal occurrence data (unverifiable observations of organisms or their sign) and inconclusive physical data are often used to assess the current and historical ranges of rare or elusive species. However, the use of such data for species conservation can lead to large errors of omission and commission, which can influence the allocation of limited funds and the efficacy of subsequent conservation efforts. We present three examples of biological misunderstandings, all of them with significant conservation implications, that resulted from the acceptance of anecdotal observations as empirical evidence. To avoid such errors, we recommend that a priori standards constrain the acceptance of occurrence data, with more stringent standards applied to the data for rare species. Because data standards are likely to be taxon specific, professional societies should develop specific evidentiary standards to use when assessing occurrence data for their taxa of interest.

Anecdotal data are considered notoriously unreliable by most scientists, and many disciplines have endeavored to limit or eliminate their influence. However, anecdotal information continues to influence our political and legal systems as well as the public’s understanding of the natural world.

[CNY_Dave]

Too easy.

Just send the earth into the sun (how is your problem).

I can guarantee total earth-animal extinction.

Unless bacteria and viruses count, plenty of them floating about in space (probably).


Dave

[Cogwheel]

Oh, it is just that earlier I was condemned for drawing conclusions without 'scientific evidence that could be repeatedly tested'...

I'm afraid I don't know anything about the groups you mentioned. I am sure they each have their line of reasoning, not that'd I'd agree with it.

What I find interesting is the two different sets of criteria for 'conclusions' there are between the two threads I have going.

There are two different sets of criteria because there are two different types of claims. One is the positive claim that something exists (ET UFOs, I gather?). The other is a negative claim of non-existence. In either case, you'll never achieve 100% certainty. The only proofs that exist are in logic/math. For a positive claim, you need to show evidence that demonstrates your claim beyond a reasonable doubt. For a negative claim, you need to consistently demonstrate a lack of evidence in order to reasonably accept nonexistence.

[realpaladin]

'I' was around for neither of those...

I said in MY experience...

...'life prevails'.


There is a minimum population necessary for a species to continue to survive. The number varies per species.

Btw, read Mr. Parcher's link. He is usually quite in the know on biology matters.

Ants..they are winning. I fight them back, eliminating large obvious mounds, but I fear they've 'learned' to keep the above mounds small and scattered...

I keeping seeing ants, I doubt seriously one could eliminate them completely.


Ants can form extremely large colonies, called super-colonies. I believe the largest of these was over 6000 kilometers in length...
And I also read something of a megacolony connecting several of these supercolonies...

They have hundreds of millions of queens...

We've been trying to 'eliminate' the wild hogs from this area, to no avail, for years. (*These are domestic hogs that escaped or were turn loose, that are not indigenous to the area, and literally wreck the country side.)

We call, hunt, track, and trap but they're still out there, smart, mobile, and elusive.

And they're just "pigs".

That is just because you want to spare the environment. You lack real tenacity.

Carpet bomb the area a few times, spray it with radio-active goo and you are pretty much there.

[Denver]

Agreed, 'life prevails in my experience'.

I'm actively engaged in trying to wipe something out, without much success.


Exactly, and you have good evidence that it has prevailed. And so, in this case, concluding it is not extinct is reasonable.


Those who claimed to hunt the Tasmanian Tiger to 'extinction' were wrong as well, it would seem.

Yes, and when better evidence came along of their existence, they reasonably changed their conclusions.

[makaya325]

A good indication of a species being extinct is if there was a certain prey it used to eat in large amounts. If that same prey's numbers are increasing, that is a good indication of the predator species extinction.

[King of the Americas]

A good indication of a species being extinct is if there was a certain prey it used to eat in large amounts. If that same prey's numbers are increasing, that is a good indication of the predator species extinction.

In the case of the Tas. Tiger, 'trying' to eliminate it, would result in a prey abundance the following season... Any remaining Tas. Tigers would have lots of easy pick'ens for a while.

Having learned that men=death, all they need do is hunt at night, and everything is set for a rebound.

[makaya325]

In the case of the Tas. Tiger, 'trying' to eliminate it, would result in a prey abundance the following season... Any remaining Tas. Tigers would have lots of easy pick'ens for a while.

Having learned that men=death, all they need do is hunt at night, and everything is set for a rebound.

What i am saying is that if a large species became extinct, its favorite prey would increase dramatically in population.

[King of the Americas]

In this instance, witness reliability cannot be tested. When it is examined, it is found to be consistently unreliable.

Here (http://forums.randi.org/showthread.php?t=132731) is a thread I started in January that is related.

Using Anecdotal Occurrence Data for Rare or Elusive Species: The Illusion of Reality and a Call for Evidentiary Standards

If someone who never saw nor heard of the "tas. tiger" described seeing an animal 'matching' its description, in the area it was known to once inhabit, what kind of evidence would that be against the tas. tiger's extinction?

Then, what if other people claimed to see an animal matching the description also? Do we need a body to confirm non-extinction?

[Marduk]

Do we need a body to confirm non-extinction?

yes, thats the whole point, you can't assume something is not extinct just because you feel like it, you need evidence.

[King of the Americas]

What i am saying is that if a large species became extinct, its favorite prey would increase dramatically in population.

The same thing would occur if you 'almost' eliminated them...

[King of the Americas]

There is a minimum population necessary for a species to continue to survive. The number varies per species.

Btw, read Mr. Parcher's link. He is usually quite in the know on biology matters.



Ants can form extremely large colonies, called super-colonies. I believe the largest of these was over 6000 kilometers in length...
And I also read something of a megacolony connecting several of these supercolonies...

They have hundreds of millions of queens...



That is just because you want to spare the environment. You lack real tenacity.

Carpet bomb the area a few times, spray it with radio-active goo and you are pretty much there.

I am waiting for the Pixar film that depicts this. They're just waiting, until they've networked ALL the ants together, then they are going to launch a massive attack...

Carpet bomb to eliminate wild pigs... I was thinking of poisoning a few food traps...

[Marduk]

The same thing would occur if you 'almost' eliminated them...
if you almost eliminated them, then they wouldn't be extinct,
seriously, get yourself a dictionary
;)

[King of the Americas]

if you almost eliminated them, then they wouldn't be extinct,
seriously, get yourself a dictionary
;)

If you 'thought' you'd totally eliminated the predator, and declared them extinct, but FAILED to kill them all, the conditions would be perfect for a natural rebound in population, BECAUSE their prey would have a population explosion...

THAT's the point I was making.

[Marduk]

firstly natural rebounds in a population depend on more than just "food"
secondly unless youre going to claim that this animal youve killed is the only predator in the environment then you don't understand how a food chain works very well, underneath the apex predator there are lots of smaller predators whos numbers are kept in check by resources and the apex predator, the second those resources start to blossom the smaller predator (which have faster birth rates than larger ones) would fill the gap left by the apex predator before it could repopulate. so there would be no niche for it left to repopulate into.

so you got it wrong because you are oversimplifying things, nature is not simple

[realpaladin]

Carpet bomb to eliminate wild pigs... I was thinking of poisoning a few food traps...

And you are wondering why you do not get the job done. Dilletante!:p

[Robster, FCD]

And you are wondering why you do not get the job done. Dilletante!:p

If you are going to utterly destroy a habitat, you need to put your heart into it.

[Soapy Sam]

Not really. Just putting up fences may be enough to stop some animals meeting to breed.
Just hunting their prey may be enough to prevent them feeding cubs. Just introducing a stressor such as adisease or parasite - possibly one we are unaware of- may be enough.

Dodos were not stupid. They wre adapted perfectly to their environment. Which changed. They were one of numerous flightless pigeons in an area lacking mammal ground predators. It didn't take sailors knocking them off for sport to wipe them out. Just introducing rats would probably have been enough. Same for all the ground nesting birds in Polynesia and Oceania.

[William Parcher]

If someone who never saw nor heard of the "tas. tiger" described seeing an animal 'matching' its description, in the area it was known to once inhabit, what kind of evidence would that be against the tas. tiger's extinction?

Then, what if other people claimed to see an animal matching the description also? Do we need a body to confirm non-extinction?


We need a body or part that confirms the continued existence. You could look at the recent case of the Ivory-billed Woodpecker. It was essentially declared as being rediscovered. But it was premature because it hasn't been confirmed with biological material. They can even use a found feather if they ever get one. It's been several years now and with government support of the search. As time goes on, it looks more and more like the rediscovery was a case of mistaken identity.

It makes no sense for the Taz Tiger to still exist without anyone bringing in a dead specimen.

[Cuddles]

The point of the post is that proving you exterminated something, is tough if not impossible.

No, all that post proved is that you, personally, are unable to make extinct multiple species with continent-spanning ranges simply by messing around within the small area of land you happen to live in. The fact that you find this in any way interesting or surprising says far more about you than it does about anything else.

[EHocking]

[quote=King of the Americas;4877362But until you could search and scour every square yard of a continent, how could you be certain you finished the job?[/quote]
Many thousands of hours have been spent over the past four field seasons combing hardwood forests and swamps for the Ivory-billed Woodpecker. But how long and how hard must you search before you can declare with near-certainty that a creature is truly gone forever? Authors from the University of Idaho, Oregon State University, the Cornell Lab of Ornithology, Point Reyes Bird Observatory and Tufts University approach this dilemma in mathematical terms. Their finding are published in the December 2008 issue of Avian Conservation and Ecology. (http://www.birds.cornell.edu/ivory/latest/ACEextinctionpaper/document_view)

The paper is available at the Cornell site.

[King of the Americas]

No, all that post proved is that you, personally, are unable to make extinct multiple species with continent-spanning ranges simply by messing around within the small area of land you happen to live in. The fact that you find this in any way interesting or surprising says far more about you than it does about anything else.

No, to me, the really interesting point is the difference in criteria for determining 'extinction' vs. continued existence.

You can conclude something went extinct w/o proven/verified evidence, and yet when it comes to verifying the continued existence of an animal 'sightings' are inadmissible.

It 'seems' like there are two different standards of proof.

[King of the Americas]

Many thousands of hours have been spent over the past four field seasons combing hardwood forests and swamps for the Ivory-billed Woodpecker. But how long and how hard must you search before you can declare with near-certainty that a creature is truly gone forever? Authors from the University of Idaho, Oregon State University, the Cornell Lab of Ornithology, Point Reyes Bird Observatory and Tufts University approach this dilemma in mathematical terms. Their finding are published in the December 2008 issue of Avian Conservation and Ecology. (http://www.birds.cornell.edu/ivory/latest/ACEextinctionpaper/document_view)

The paper is available at the Cornell site.

GOOD stuff: (taken from the paper)

"...Rediscovery of “extinct” species occurs often enough to give one pause about making premature pronouncements. The Bermuda Petrel (Petrodroma cahow) was considered extinct by 1621, but a small breeding colony was discovered in 1951 (Murphy and Mowbray 1951). Gurney’s Pitta (Pitta gurneyi) in Myanmar (Eames et al. 2005), a freshwater pearl mussel (Margaritifera margaritifera) in Portugal (Reis 2003), the Cherry-throated Tanager (Nemosia rourei) in Brazil (Bauer et al. 2000), Bulmer’s fruit bat (Aproteles bulmerae) in Papua New Guinea (Flannery 1994), Wollemi pine (Wollemia nobilis) in Australia (Woodford 2002)—all were thought to be extinct for decades or known only from fossil remains until rediscovered in recent years. In fact, the phenomenon of prematurely declaring species extinct is common enough to have been christened “Romeo’s error” (Collar 1998) and the “Lazarus effect” (Keith and Burgman 2004).

The World Conservation Union defines a species as extinct if there is “no reasonable doubt that the last individual has died” (IUCN 2001). Determining the point of “no reasonable doubt,” however, is tricky. Although the rediscovery of some presumably extinct species has happened serendipitously, more often it is associated with a focused search effort. When systematic searches occur, the effort required to find a rare species with low detectability can be substantial (Scott et al. 1986, Solow 1993, Reed 1996). For example, over a 6-week period in 2006, a team of scientists used sophisticated technology to search 3500 km of the Yangtze River in China in an attempt to find the Yangtze River dolphin (Lipotes vexillifer). Their failure led to the decision in August 2007 to declare the species officially extinct (Turvey et al. 2007). But, even though the search effort was intensive and one would think an animal the size of a dolphin would be hard to miss, there is uncertainty about whether the search effort was adequate to make such a terminal decision. In fact, a possible sighting (and filming) of a Yangtze River dolphin was reported later in August 2007 (http://news.bbc.co.uk/2/hi/science/nature/6969226.stm). The recently reported rediscovery (Fitzpatrick et al. 2005) of the Ivory-billed Woodpecker (Campephilus principalis) has captured the imagination of the American public and given new hope for its recovery (Walters and Crist 2005). The lack of indisputable evidence and alternative explanations of the original data, however, have raised doubts about the species’ status (Jackson 2006, Sibley et al. 2006, Stokstad 2007). Rigorous quantitative estimates of the likelihood of persistence in a given area would help to clarify the situation..."

Declaring something extinct IS an imperfect science.

[King of the Americas]

We need a body or part that confirms the continued existence. You could look at the recent case of the Ivory-billed Woodpecker. It was essentially declared as being rediscovered. But it was premature because it hasn't been confirmed with biological material. They can even use a found feather if they ever get one. It's been several years now and with government support of the search. As time goes on, it looks more and more like the rediscovery was a case of mistaken identity.

It makes no sense for the Taz Tiger to still exist without anyone bringing in a dead specimen.

Relying on senses is senseless.

That's funny.

Read that Cornell paper linked below. Good stuff.

[King of the Americas]

Not really. Just putting up fences may be enough to stop some animals meeting to breed.
Just hunting their prey may be enough to prevent them feeding cubs. Just introducing a stressor such as adisease or parasite - possibly one we are unaware of- may be enough.

Dodos were not stupid. They wre adapted perfectly to their environment. Which changed. They were one of numerous flightless pigeons in an area lacking mammal ground predators. It didn't take sailors knocking them off for sport to wipe them out. Just introducing rats would probably have been enough. Same for all the ground nesting birds in Polynesia and Oceania.

Good point, the introduction of a feeder species upon their young/eggs, does tend to wipe stuff out...

The 'hogs' in question have grown 'smarter'. The first traps they set, would often capture a half dozen at a time, due to the 'heavy baiting methods' employed. Now, the traps are empty, or hold only a young single male. They find tracks around the trap, and we've got photos of them visiting, but they won't go in. Even the camo-ed traps are sniffed out after a capture.

These things can live on 'roots', they're fast, and move mostly at night. They've proven to be more than resistant to extermination efforts. I'd say they are downright successful. The most success we've had is with dogs. (*shhh, don't tell peta)

[paximperium]

You can conclude something went extinct w/o proven/verified evidence, and yet when it comes to verifying the continued existence of an animal UNCONFIRMED 'sightings' are inadmissible. Corrected for honesty.

It 'seems' like there are two different standards of proof.
Most definitely.:rolleyes:

[ZirconBlue]

Declaring something extinct IS an imperfect science.

Which sciences are perfect?

[lomiller]

Which sciences are perfect?

I’d suggest that *proving* an extinction isn’t science at all.

The scientific method is a structured form of inductive logic. In any form of inductive logic you bring forward positive evidence to support your hypothesis. You don’t, indeed you cannot, disprove every possible alterative. Disproof, showing the hypothesis contradicts the data, really only comes into play if there are multiple hypothesis being advanced with positive evidence. Put into the form of a basic rule of thumb that often gets lost under the guise of “support your claim” is that you don’t (usually) need to prove a negative.

In the case of extinction, you can hypothesize the species is extinct then test that hypothesis by looking for it in what was known to be it’s range and by looking for verifiable observations. If, after significant searching you don’t find anything you can conclude it’s likely extinct.

After that it’s no longer up to you to prove extinction, it’s up to the people who disagree to provide their own proof. If they think you didn’t look hard enough, then they need to go out and look for themselves because only they know what they consider to be hard enough. If they think it may living in some other range, they need to inspect that range themselves.

The key is that after the original claim is shown to be consistent, it’s up to the people who still disagree to offer up their own competing claim/evidence, simply generating a list of things that “haven’t been disproven” isn’t enough because that list is endless.

[King of the Americas]

Corrected for honesty.

Most definitely.:rolleyes:

How do you 'confirm' a sighting? If someone else sees it to? I mean, if it is a sighting and not a picture?

Really, it's OKAY that there are 2 'different' standards for existence vs. extinction???

That seems to me, crazy.

[realpaladin]

Which sciences are perfect?

My science of making 'Spaghetti Bolognese a la RealPaladin'!

[realpaladin]

How do you 'confirm' a sighting? If someone else sees it to? I mean, if it is a sighting and not a picture?

Really, it's OKAY that there are 2 'different' standards for existence vs. extinction???

That seems to me, crazy.

No, actually both are the same; something is extinct or does not exist unless it is confirmed not to be extinct, after which we conclude it exists.

[makaya325]

King, it is simple as this:

no tracks, no scat, no remains, no ecosystem impact, increase in prey,etc= Extinction of the predator species.

[Marduk]

Which sciences are perfect?


My science of casanovology
:D
oh and pure mathematics, allegedly, only if youre really really good at it

[Cainkane1]

You don't hunt them individually you destroy their environment.

[King of the Americas]

King, it is simple as this:

no tracks, no scat, no remains, no ecosystem impact, increase in prey,etc= Extinction of the predator species.

Agreed.

Now which of those would re-qualify it, back into non-extinction?

[realpaladin]

Agreed.

Now which of those would re-qualify it, back into non-extinction?
Nice try.

Answer: a consistent subset which makes fakes implausible and rules out errors in identification, or all of them.

A living specimen would be the pinnacle.

[paximperium]

Nice try.

Answer: a consistent subset which makes fakes implausible and rules out errors in identification, or all of them.

A living specimen would be the pinnacle.
Even a dead or a carcass bigfoot specimen would be a start.

[I Ratant]

In my experience 'life prevails'... You can't ever wipe ALL of them out.
.
Labrador Duck
Carrier Pigeon
Great Auk
Cave Sloth
Cave Bear
Dodo...
... the list of animals taken to extinction by man is basically endless.
This is yet another subject you are waxing eloquent on, from a position of ignorance.

[William Parcher]

Carrier Pigeon


You meant Passenger Pigeon.

I'd also add a couple other notables:

Carolina Parakeet
Ivory-billed Woodpecker (very probably extinct)

[William Parcher]

no tracks, no scat, no remains, no ecosystem impact, increase in prey,etc

Now which of those would re-qualify it, back into non-extinction?


The remains would do it, as would a live specimen. Ecological impact is not confirmatory evidence in itself. Scat, hair, feathers, etc. could be confirmatory if DNA is present or if the material physically matches existing samples and can be shown to be from a recently-living animal. The I-B Woodpecker searchers could confirm its continued existence by simply finding a feather or eggshell. High quality photos or video would be very compelling and could possibly serve as confirmation in certain circumstances.

[shadron]

Ants can form extremely large colonies, called super-colonies. I believe the largest of these was over 6000 kilometers in length...
And I also read something of a megacolony connecting several of these supercolonies...

They have hundreds of millions of queens...

Sounds like a really scary conspiracy to me - B, maybe C movie material.

About the ants; see this article: http://news.bbc.co.uk/2/hi/science/nature/1932509.stm

The definition of a supercolony as a “group of nests” is an unbelievable understatement. The largest of these supercolonies (http://news.bbc.co.uk/2/hi/science/nature/1932509.stm) is in Southern Europe and stretches for over 6,000 kilometers! Another 600-mile long supercolony exists in California (http://news-service.stanford.edu/news/2004/april7/antstudies-47.html). And yet another 100km supercolony has been discovered (http://news.bbc.co.uk/2/hi/science/nature/3561352.stm) under Melbourne Australia.from http://www.randomstew.com/2007/10/26/ant-supercolony/ I think the author doesn't really understand the significance of the definition; he's envisioning underground cities, universities and a Parris Island.

Apparently, when the Argentinian ants are imported into a virgin area, they proliferate from a single small start-up colony, and the ants that result are so genetically identical that they all smell to each other like they are all members of the same colony, so they don't fight each other as they do in Argentina. The colonies aren't huge underground cross-tunneled dens of secret meetings, trade negotiations and pulsating green brains; they are merely normal, physically unconnected ant colonies whose members don't fight at interaction. It is doubtful that their friendly interactions are helping the colonies cooperate significantly (which could result in the green brains), because they don't have the hardwired behaviors to take advantage of that; that to, would have to be mutated into being, and they have very little, if any, learning software. The theory is that as they adapt to their environments and start to drift genetically, they will resume their antagonism to each other as their pheromone formulas drift.

The definition of a super-colony is that you can take two soldier ants, one from each of two suspected member colonies, and they will not engage to kill each other.

It is genetically to their advantage to fight, after all. It promotes better colonization, and if they are too cooperative, they will quickly strip an area of food, and like bacteria on the inside of a colony, starve to death. They could be just too efficient for their own good.

[I Ratant]

You meant Passenger Pigeon.

I'd also add a couple other notables:

Carolina Parakeet
Ivory-billed Woodpecker (very probably extinct)
.
Yeah...
And Smallpox.
Only exists in labs.
Polio almost got there, except for some mullahs and Imams railing against vaccinations.
The "sightings" of the Ivory-billed Woodpecker sound more like wishful BigFoot believers than anything else.

[makaya325]

Ecological impact is not confirmatory evidence in itself

Why not? Lets assume a large carnivore inhabits a specific area and has a favorite meal it preys on: How can you tell if the Carnivore is still around? By noticing depletion in Prey populations, and increase in Trace evidence of the Carnivore. The ecosystem is like a puzzle: If one piece is missing, then the food web looks quite different.

[makaya325]

High quality photos or video would be very compelling and could possibly serve as confirmation in certain circumstances.[


I thought video evidence COULD be faked? :rolleyes:

[William Parcher]

Why not? Lets assume a large carnivore inhabits a specific area and has a favorite meal it preys on: How can you tell if the Carnivore is still around? By noticing depletion in Prey populations, and increase in Trace evidence of the Carnivore. The ecosystem is like a puzzle: If one piece is missing, then the food web looks quite different.


It can't serve as confirmation because it isn't evidence of the animal itself... it's implied evidence. A survey of wallabies may show their population is effected by Tasmanian Wolf predation. But confirmation must come from other kinds of evidence such as was already mentioned. You need something to show for the animal itself, not just show what it is (might be) eating.


I thought video evidence COULD be faked?


That's why I said in certain circumstances. The visual evidence must be unambiguous and not faked or altered.

[makaya325]

It can't serve as confirmation because it isn't evidence of the animal itself... it's implied evidence. A survey of wallabies may show their population is effected by Tasmanian Wolf predation. But confirmation must come from other kinds of evidence such as was already mentioned.

I know that it is not direct evidence, but it remains as of the the best trace evidence for an animal: If we know what it eats, and if its prey increases/decreases, then the animal population must be either dwindling or increasing.

[QUOTE]You need something to show for the animal itself, not just show what it is (might be) eating.

What if this type of prey is ONLY eaten by the carnivorous species?




That's why I said in certain circumstances. The visual evidence must be unambiguous and not faked or altered.

Certain circumstances?

[William Parcher]

I know that it is not direct evidence, but it remains as of the the best trace evidence for an animal: If we know what it eats, and if its prey increases/decreases, then the animal population must be either dwindling or increasing.


The direct evidence is what is needed for confirmation. Missing or found predated wallabies does not necessarily equate to Taz Wolfs. The predator could be Dingoes or domestic/feral dogs instead. It would require finding stuff like hair, scat, definitive tracks, etc.

What if this type of prey is ONLY eaten by the carnivorous species?

See above.


Certain circumstances?

Yeah. Circumstances where there is high confidence that the visual evidence is legitimate. There is such a thing. Hanging out with the crypto crowd can make you cynical of such things because so much is faked or is ambiguous. Further, there are sophisticated technological means to determine if images or video have been altered.

[makaya325]

The direct evidence is what is needed for confirmation. Missing or found predated wallabies does not necessarily equate to Taz Wolfs. The predator could be Dingoes or domestic/feral dogs instead. It would require finding stuff like hair, scat, definitive tracks, etc.

That is true, but what if there is nothing else that can take down the certain kind of prey except the carnviore? I am just saying: Ecological impacts are stronger evidence in certain kinds of situations.







Yeah. Circumstances where there is high confidence that the visual evidence is legitimate. There is such a thing. Hanging out with the crypto crowd can make you cynical of such things because so much is faked or is ambiguous. Further, there are sophisticated technological means to determine if images or video have been altered

The Crypto crowd has a reason to be cynical because they are duped alot by fake videos.

[makaya325]

The predator could be Dingoes or domestic/feral dogs instead. It would require finding stuff like hair, scat, definitive tracks, etc.

What if bite marks found on the prey is consistent only with that of the carnivore in question?

[William Parcher]

That is true, but what if there is nothing else that can take down the certain kind of prey except the carnviore? I am just saying: Ecological impacts are stronger evidence in certain kinds of situations.

What if bite marks found on the prey is consistent only with that of the carnivore in question?


Then you have non-confirmatory evidence of the presence of that animal. The next step is to look for direct evidence. If the animal exists and the local ecology shows it - then it (or confirmatory evidence) will be found. Camera traps are quite efficient at detecting animals even in low density populations.

[makaya325]

Camera traps are quite efficient at detecting animals even in low density populations

That is correct: Snow leopards, Javan Rhinos, Wolverines, and other rare animals all have been captured on camera trap.

Only Bigfoot, with his Superior skills, can dissapear into another dimension. It's Common sense, duh! :rolleyes:

[I Ratant]

That is correct: Snow leopards, Javan Rhinos, Wolverines, and other rare animals all have been captured on camera trap.

Only Bigfoot, with his Superior skills, can dissapear into another dimension. It's Common sense, duh! :rolleyes:
.
Camera trap images in the Southwestern US..

[makaya325]

.
Camera trap images in the Southwestern US..

This proves that bigfoot uses his blurry mechanism to not be captured cleary, and doesnt like showing his acne. :D

[Damien Evans]

...how do you do that exactly?

Say I wanted to hunt something TO extinction, how could I be 'absolutely' certain I finished the job.

And if it were an illusive predator, the job may be really difficult.

If an animal 'learns' that human=death, finding them on foot would be all but impossible.

But until you could search and scour every square yard of a continent, how could you be certain you finished the job?

No confirmed sightings for 50 years equals extinct.

http://en.wikipedia.org/wiki/Thylacine

[Damien Evans]

Didn't we 'try' to hunt wolves to extinction, here?

They 'claimed' to have hunted the Tasmanian Tiger to extinction, but there are still sightings that occur.

Isn't it probable that something(s) thought to be gone, to have found a home outside of our perception?

The strong survive, for a reason. If an animal learned that human 100% = DEATH, why couldn't they 'totally' avoid us?

We did hunt the Thylacine to extinction, and we're bloody ashamed that we did now. No 'claimed' about it.

[realpaladin]

<snippety for brevity>
It is genetically to their advantage to fight, after all. It promotes better colonization, and if they are too cooperative, they will quickly strip an area of food, and like bacteria on the inside of a colony, starve to death. They could be just too efficient for their own good.

But you have to agree, the green brains image is way cooler :)

[Damien Evans]

Exactly, and you have good evidence that it has prevailed. And so, in this case, concluding it is not extinct is reasonable.



Yes, and when better evidence came along of their existence, they reasonably changed their conclusions.

What in the name of christ on a cheesecake are you blathering on about?

There isn't any confirmed evidence for the survival of the Thylacine past 1936.

[Damien Evans]

If someone who never saw nor heard of the "tas. tiger" described seeing an animal 'matching' its description, in the area it was known to once inhabit, what kind of evidence would that be against the tas. tiger's extinction?

Then, what if other people claimed to see an animal matching the description also? Do we need a body to confirm non-extinction?

No, but it would certainly do the trick, as would reliable video footage, tracks belonging to the animal, droppings, etc.

[Damien Evans]

We need a body or part that confirms the continued existence. You could look at the recent case of the Ivory-billed Woodpecker. It was essentially declared as being rediscovered. But it was premature because it hasn't been confirmed with biological material. They can even use a found feather if they ever get one. It's been several years now and with government support of the search. As time goes on, it looks more and more like the rediscovery was a case of mistaken identity.

It makes no sense for the Taz Tiger to still exist without anyone bringing in a dead specimen.

It'd be much better if they brang in a live specimen, since unless it was already dead when thy found it killing it would break several laws.

[Damien Evans]

The direct evidence is what is needed for confirmation. Missing or found predated wallabies does not necessarily equate to Taz Wolfs. The predator could be Dingoes or domestic/feral dogs instead. It would require finding stuff like hair, scat, definitive tracks, etc.



See above.




Yeah. Circumstances where there is high confidence that the visual evidence is legitimate. There is such a thing. Hanging out with the crypto crowd can make you cynical of such things because so much is faked or is ambiguous. Further, there are sophisticated technological means to determine if images or video have been altered.

Actually, while it could be a feral dog it couldn't be a Dingo, they never reached Tasmania.

[Damien Evans]

.
Camera trap images in the Southwestern US..

What animals are those in the top 2 images?

My Aussie eyes don't recognise them.

[makaya325]

What animals are those in the top 2 images?

My Aussie eyes don't recognise them.

The left one looks like a Bob cat, while I am unsure of the middle one.

[William Parcher]

Mountain Lion, Coatimundi, Collared Peccary, Illegal Immigrant.

[makaya325]

Illegal Immigrant

I hope that your better than that: Dont confirm to stereotypes.

[William Parcher]

I hope that your better than that: Dont confirm to stereotypes.


4:34am timestamp. It's the pool guys showing up to clean the water tank.

[Denver]

What in the name of christ on a cheesecake are you blathering on about?

There isn't any confirmed evidence for the survival of the Thylacine past 1936.

My mistake - I thought we were discussing an animal that had been thought extinct and then later rediscovered.

Still, just pointing out the error without accusations of 'blathering', etc, is usually sufficient.

[JoeTheJuggler]

How to "prove" an extinction:

Prepare the extinction in a proper homeopathic solution. Have a healthy person take the solution and then record absolutely any symptoms that person has (or thinks he has). . .


But seriously, I'm sure the thread has touched on this, but I don't think biologists "prove" extinction because then you get the "All swans are white" logical problem (or better yet, "There are no non-white swans".) Instead, you build up evidence for an extinction, and the evidence required would vary from one species to another. When the evidence is sufficient, you provisionally accept the claim that the species is extinct.

[Cuddles]

No, to me, the really interesting point is the difference in criteria for determining 'extinction' vs. continued existence.

You can conclude something went extinct w/o proven/verified evidence, and yet when it comes to verifying the continued existence of an animal 'sightings' are inadmissible.

It 'seems' like there are two different standards of proof.

Of course there are two different standards of proof. In fact, there are infinitely many different standards, one for every claim that is made. This is because no two claims are identical, and they all have differing prior probability, different amounts of existing evidence, and different consequences if they turn out to be correct. What I don't understand is why you appear to be confused by this or consider it a bad thing.

Consider socks. I claim that I posses at least one sock. How would you test this claim? The obvious thing would be to visit my house and look in my sock drawer. It turns out there are in fact several socks in my sock drawer. Claim proven.

Alternatively, I claim that I do not have any socks and that there are none in my flat at all. How would you test this? Well, first you might check my sock drawer again. If you find a sock, the claim has been disproved. On the other hand, if you don't find a sock, you haven't proved anything. You now have to check the other drawers, the cupboard, the floor, the washing machine, behind the sofa, under the bed, on my feet, and so on.

Do you understand yet? Two claims, one for positive existence and one for negative, yet two very different standards of evidence. The former can be proven to a high degree, although never quite conclusively - the sock seen in my drawer may turn out not to be mine, for example. The latter can never be proven with as much certainty, since there may always be another place you have not yet thought of searching or you may simply have missed seeing a sock somewhere, but once you have spent a certain amount of time and effort looking in the expected places, you can conclude fairly reasonably that there are, in fact, no socks.


An important related point relates to the oft-repeated phrase "absence of evidence is not evidence of absence". This is not always correct. Absence of evidence is certainly not proof of absence, but it can actually be very good evidence of absence. In the sock example above, failing to find a sock in my sock drawer does not prove I have no socks, but if you know that I used to have many socks and they were always kept in the sock drawer, it is evidence that something may have happened to the socks.

To give a slightly more serious example, imagine some creature living on a remote island. It has only ever been seen no this island, and there seems to be no way for it to have colonised anywhere else. The island is mostly covered with thick forests and it is a small, quick creature that is very hard to spot in that environment. However, there is a lake on the island that is the only known source of drinking water, and every year when a scientific expedition arrives they visit the lake to survey what lives on the island. Every year, they see numerous members of this species drinking there.

One year, the expedition arrives as usual, but in the whole time they are at the lake, they don't see a single one of these creatures. Is that conclusive proof that the creature has gone extinct? Certainly not. They could have found a different water source to drink from. They could have died out here but still exist on another, undiscovered island. But it sure as hell is evidence of its absence.

The (slightly long-winded) point is that while absence of evidence may not always be evidence of absence, absence of evidence where you would expect such evidence to present, is. If you don't find any socks in your sock drawer, it's evidence your socks have gone missing. If you don't see an animal in a place where it's always been observed, it's evidence that something has happened to that animal. And if you continue to fail to see that animal anywhere over a long period of time, it eventually builds up to pretty strong evidence that the animal simply isn't there to be seen any more.

[King of the Americas]

That is correct: Snow leopards, Javan Rhinos, Wolverines, and other rare animals all have been captured on camera trap.

Only Bigfoot, with his Superior skills, can dissapear into another dimension. It's Common sense, duh! :rolleyes:

Do you think that there are animals that 'completely' avoid human interaction?

When we 'camp' in the woods, we notice that most of the animal life, moves away for the first few days.

Is it impossible to imagine, that we leave traces of our behavior, setting up these camera traps, and that these traces 'taint' the sight from future visitation?

If humans hunted and killed 95% of your population you too might decide to avoid humans 'altogether'.

[Damien Evans]

Mountain Lion, Coatimundi, Collared Peccary, Illegal Immigrant.

Thanks. I knew the Peccary though, we have some in our zoo.

[King of the Americas]

...still exist on another, undiscovered island. But it sure as hell is evidence of
The (slightly long-winded) point is that while absence of evidence may not always be evidence of absence, absence of evidence where you would expect such evidence to present, is. If you don't find any socks in your sock drawer, it's evidence your socks have gone missing. If you don't see an animal in a place where it's always been observed, it's evidence that something has happened to that animal. And if you continue to fail to see that animal anywhere over a long period of time, it eventually builds up to pretty strong evidence that the animal simply isn't there to be seen any more.

Alright, so what if you claimed to have no socks, but several people say they saw you wearing them, and we even have a picture that could be faked, showing you wearing them.

But without a court order we can't search your flat...

Can or should we conclude that you are lying?

[King of the Americas]

No, but it would certainly do the trick, as would reliable video footage, tracks belonging to the animal, droppings, etc.

video footage, can be faked

tracks, can be faked

droppings, get rolled away thanks to dung beetles

---

bones, get eaten by 'devils' or other bone consuming mammals

pictures, are easy to fake

eye witness accounts, are unreliable

[ZirconBlue]

Even a dead or a carcass bigfoot specimen would be a start.


Of course the carcass could be the remains of the last surviving member of the species. So the creature that was once thought to be extinct, would, in fact not have been extinct previously, but could be now extinct.

:hypnotize

[William Parcher]

Certain circumstances?


Wolverines in California (http://www.dfg.ca.gov/news/issues/wolverine/)


A series of camera trap photos. This is an example of images that can be declared legitimate with high confidence.

[JoeTheJuggler]

Of course there are two different standards of proof. In fact, there are infinitely many different standards, one for every claim that is made. This is because no two claims are identical, and they all have differing prior probability, different amounts of existing evidence, and different consequences if they turn out to be correct. What I don't understand is why you appear to be confused by this or consider it a bad thing.

Consider socks. I claim that I posses at least one sock. How would you test this claim? The obvious thing would be to visit my house and look in my sock drawer. It turns out there are in fact several socks in my sock drawer. Claim proven.

I think part of the problem is that people are mixing up the scientific method and logical proofs. They're not the same.

A scientist can conclude that a species is extinct because that's the conclusion the evidence points toward. This is not the same as a logical proof that a species is extinct.

Generally, in hypothesis testing, about all we can do is eliminate the null hypothesis with some degree of confidence in order to build support for the hypothesis.

[I Ratant]

The left one looks like a Bob cat, while I am unsure of the middle one.
.
Bobcat in a local schoolyard... note the short tail..
I keep hoping to see the cougars said to be in the area.

[I Ratant]

Mountain Lion, Coatimundi, Collared Peccary, Illegal Immigrant undocumented probationary citizens .
.
Fixed that for ya. :)

[I Ratant]

...
eye witness accounts, are unreliable
.
This from the UFO historian! :covereyes

[I Ratant]

Wolverines in California (http://www.dfg.ca.gov/news/issues/wolverine/)


A series of camera trap photos. This is an example of images that can be declared legitimate with high confidence.
.
But you won't find any grizzlies.. the California State Animal. They're -extinct- in California.

[makaya325]

]Do you think that there are animals that 'completely' avoid human interaction?

Certaintly, but they can still be found rather easily by Widlife biologists and field guides.

[blutoski]

Do you think that there are animals that 'completely' avoid human interaction?

When we 'camp' in the woods, we notice that most of the animal life, moves away for the first few days.

Is it impossible to imagine, that we leave traces of our behavior, setting up these camera traps, and that these traces 'taint' the sight from future visitation?

If humans hunted and killed 95% of your population you too might decide to avoid humans 'altogether'.

That makes perfect sense... until the creature croaks, after which it has no choice in the matter.

eg: I've never seen a live grizzly while hiking, but I've come across remains from time to time.

Or are these cryptos assumed to be immortal?

[makaya325]

Or are these cryptos assumed to be immortal

No, just breaking every law of nature. :rolleyes:

[blutoski]

No, to me, the really interesting point is the difference in criteria for determining 'extinction' vs. continued existence.

You can conclude something went extinct w/o proven/verified evidence, and yet when it comes to verifying the continued existence of an animal 'sightings' are inadmissible.

It 'seems' like there are two different standards of proof.

They're different claims and different types of conclusions, right? Claims for nonexistence can only be tentatively be supported inductively. Claims for existence can be solidly proven with a single example.

I appreciate that this bothers some people, but when you think about it, showing something exists is a lot easier than showing something is extinct... if it actually exists.

And 'sightings' aren't inadmissable - they're just a weak form of evidence. Evidence is evaluated for its strength in an overall context. That's basic critical thinking.

[makaya325]

And 'sightings' aren't inadmissable - they're just a weak form of evidence. Evidence is evaluated for its strength in an overall context. That's basic critical thinking

Evidence? Tell that to the missing red panda of Rotterdam.

[King of the Americas]

That makes perfect sense... until the creature croaks, after which it has no choice in the matter.

eg: I've never seen a live grizzly while hiking, but I've come across remains from time to time.

Or are these cryptos assumed to be immortal?

No, but they aren't as common bears either.

[makaya325]

No, but they aren't as common bears either.

There are no rarer than the pink unicorn or the waterhorse. ;)

[Skeptical Greg]

Being poorly informed is quite different than being 'ignorant'.
....
When did this distinction take effect ?

[realpaladin]

There are no rarer than the pink unicorn or the waterhorse. ;)

*Burppp*... sorry, make that just 'the waterhorse'.
* realpaladin picks his teeth and cleans the barbie.

[Marduk]

When did this distinction take effect ?

when he realised that he couldn't be bothered to research anything for himself
:p

[Cuddles]

Alright, so what if you claimed to have no socks, but several people say they saw you wearing them, and we even have a picture that could be faked, showing you wearing them.

But without a court order we can't search your flat...

Can or should we conclude that you are lying?

I believe that whooshing sound was the point flying way over your head.

I think part of the problem is that people are mixing up the scientific method and logical proofs. They're not the same.

A scientist can conclude that a species is extinct because that's the conclusion the evidence points toward. This is not the same as a logical proof that a species is extinct.

Generally, in hypothesis testing, about all we can do is eliminate the null hypothesis with some degree of confidence in order to build support for the hypothesis.

Exactly. It seems that believers in many silly things love to conflate the perfectly sensible skeptical that something probably does or doesn't exist with the claim that it is 100% certain that it does or doesn't exist. KotA provides a perfect example. The balance of evidence suggests an animal is extinct, so he says that all skeptics are absolutely certain it must be extinct and that they must therefore be saying anyone or anything that could possibly suggest otherwise must be a lie.

It's just sad really. I'm not sure if he (and they) really believe this kind of thing or if it's just some kind of defence mechanism to avoid admitting that a belief is false. There is always likely to be conflicting evidence of most things. An animal seems to be extinct, but someone thinks they saw one. Are they lying? Probably not. Are they mistaken? Quite likely. But it's still evidence, just not enough evidence to throw out all previous conclusions as KotA and people like him would have us do.

[blutoski]

No, but they aren't as common bears either.

How do you know that?

[King of the Americas]

http://en.wikipedia.org/wiki/Gigantopithecus

"...Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens..."

---

My question is how do you prove an extinction? I know one way would be to prove that the life form required a certain environment to exist, and that said environment has been destroyed. I suppose another way would be to eliminate said extinctee's sole food source, that might end something existence.

The Coelacanth was thought to be extinct, until someone caught one just a few years ago.

If you can't eliminate every known food source, and eliminate every known environment where said extinctee existed, they then might not be extinct at all.

If Gigantopithecus co-existed with our ancestors, then maybe they managed to find nitches to carve out meager existences... Maybe they've made a living NOT being seen or found, or maybe they were hunted to the point of genetic deprivation, and all died out.

Then again, maybe they developed enough intelligence to equate hidden with survival. Primates ARE smart, right?

Maybe they eat their dead, as to destroy all evidence of their existence, maybe they bury their dead, who knows. There's a LOT of wilderness in the world, and primates have proven to be resourceful creatures.

I certainly wouldn't argue that we've eliminated every one of their potential food sources, nor have we eliminated every environment in which they could exist.

Maybe declaring that bigfoot or "Gigantopithecus" is extinct, is premature...

[William Parcher]

Maybe declaring that bigfoot or "Gigantopithecus" is extinct, is premature...


This is just another "Bigfoot Exists" thread by a believer, right?

[John Jones]

http://en.wikipedia.org/wiki/Gigantopithecus

"...Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens..."

---

My question is how do you prove an extinction? I know one way would be to prove that the life form required a certain environment to exist, and that said environment has been destroyed. I suppose another way would be to eliminate said extinctee's sole food source, that might end something existence.

The Coelacanth was thought to be extinct, until someone caught one just a few years ago.

If you can't eliminate every known food source, and eliminate every known environment where said extinctee existed, they then might not be extinct at all.

If Gigantopithecus co-existed with our ancestors, then maybe they managed to find nitches to carve out meager existences... Maybe they've made a living NOT being seen or found, or maybe they were hunted to the point of genetic deprivation, and all died out.

Then again, maybe they developed enough intelligence to equate hidden with survival. Primates ARE smart, right?

Maybe they eat their dead, as to destroy all evidence of their existence, maybe they bury their dead, who knows. There's a LOT of wilderness in the world, and primates have proven to be resourceful creatures.

I certainly wouldn't argue that we've eliminated every one of their potential food sources, nor have we eliminated every environment in which they could exist.

Maybe declaring that bigfoot or "Gigantopithecus" is extinct, is premature...


Wow. That's some wishful thinking right there.

[Cainkane1]

I'd bet money giganthropithicusinc is extinct, bigfoot is a myth and its all woo.

[King of the Americas]

This is just another "Bigfoot Exists" thread by a believer, right?

Nope.

I was hoping this could be a discussion about environments, food sources, and determining actual extinctions.

[William Parcher]

Nope.

I was hoping this could be a discussion about environments, food sources, and determining actual extinctions.

Did you forget that we already have a thread on this exact subject (http://forums.randi.org/showthread.php?t=147422) which was started by you?! The thread is called "'Proving' an extinction..."

Bigfoot came up there too and you said this...

People KEEP seeing it, so it isn't extinct.

So yeah, I'm thinking you made this redundant thread so that you can again argue that Bigfoot is out there.

[King of the Americas]

Did you forget that we already have a thread on this exact subject (http://forums.randi.org/showthread.php?p=4888104) which was started by you?! The thread is called "'Proving' an extinction..."

Bigfoot came up there too and you said this...



So yeah, I'm thinking you made this redundant thread so that you can again argue that Bigfoot is out there.

Thanks, man.

---

Moderators, could you guys do your merge thing?

[Marduk]

Nope.

I was hoping this could be a discussion about environments, food sources, and determining actual extinctions.

Like you mean how Gigantopithecus existed in China, India, and Vietnam and the hypothetical Bigfoot lives in the Pacific northwest

would you like to discuss how an arboreal primate known to favour caves just got up one day and decided to go on a 12,000 mile walk through the tundra ?

btw your celeocanth reference is a typical mistake made by someone that doesn't know anything about celeocanths, the modern fish is the last in a lineage of a class of the lobe finned fishes, it is not at all similar to its dead relatives, what you did there is like saying "look, see that Lemur, thats a human that is"
:p

I know you won't answer this post, you never answer any posts that question your fantasy with facts do you

[RoboTimbo]

KotA, I have a theory* that one specimen of each type of dinosaur still exists. When that one specimen ages and approaches death, it pukes up a newborn and raises it until it is old enough to fend for itself. The young then breathes fire on the older one, burning it to a cinder. The young then buries itself 572 feet deep in mud and doesn't emerge until it has to start the cycle all over again.

They don't eat anymore, they can only absorb nutrients through their skin from the surrounding mud. The reason they don't eat anymore is because their preferred food was Gigantopithecus. Therefore, Gigantopithecus is extinct. The existence of the dinosaurs proves it.

It's the only theory* that fits all the evidence.






*not by any stretch of the imagination a theory

[Roboramma]

btw your celeocanth reference is a typical mistake made by someone that doesn't know anything about celeocanths, the modern fish is the last in a lineage of a class of the lobe finned fishes, it is not at all similar to its dead relatives, what you did there is like saying "look, see that Lemur, thats a human that is"

Not quite the same: a Lemur isn't a descendant of a human. And depending on how you define extinction, modern coelacanths do show that they never went extinct. The population has continually existed and reproduced, it's just changed. I consider that a meaningful and useful way to discuss the subject.

[Roboramma]

The Coelacanth was thought to be extinct, until someone caught one just a few years ago.

"Just a few years ago"?

The coelacanths, which are related to lungfishes and tetrapods, were believed to have been extinct since the end of the Cretaceous period. More closely related to tetrapods than even the ray-finned fish, coelacanths were considered the "missing link" between the fish and the tetrapods until the first Latimeria specimen was found off the east coast of South Africa, off the Chalumna River (now Tyalomnqa) in 1938

[Vortigern99]

http://en.wikipedia.org/wiki/Gigantopithecus

"...Dating methods have shown that G. blacki existed for about a million years, going extinct about 100,000 years ago after having been contemporary with (anatomically) modern humans (Homo sapiens) for tens of thousands of years, and co-existing with H. erectus before the appearance of H. sapiens..."

---

My question is how do you prove an extinction? I know one way would be to prove that the life form required a certain environment to exist, and that said environment has been destroyed. I suppose another way would be to eliminate said extinctee's sole food source, that might end something existence.

Another possible way to "prove an extinction" -- insofar as a negative can logically be proven -- might be to discard:

* all anecdotal evidence for the animal in question, since regional expectation, the Red Panda effect, unintentional misidentification, willful hoaxing, hallucination during hypnagogia and/or drug-altered states, and fraud handily account for all such tall tales;

* all ambiguous, unreliable, hoaxable pieces of evidence, such as footprints, blurry ape-suit snapshots and "inconclusive" DNA samples;

... then examine the unambiguous, reliable, non-hoaxable physical evidence that remains.

In this case, there is none to examine.

The Coelacanth was thought to be extinct, until someone caught one just a few years ago.

The important consideration here, which bigfoot believers and proponents often overlook or ignore, is that someone caught one a few years ago. The coelacanth (http://en.wikipedia.org/wiki/Coelacanth) is a known, documented, captured and catalogued animal. Its existence can hardly be used as an example of some elusive, oft-reported creature of myth which turned out to exist after all.

There were no legends of coelacanths lurking in the waters of Indonesia before one turned up in a fish market. It is not comparable or analogous to bigfoot in any rational way.

Recently a team of scientists captured the only known specimen of wolverine in the state of California -- a male who had wandered in from a neighboring state. First they caught the little critter on a "trail-cam" set up to watch birds; then, following a tracking operation through the very habitat bigfoot is supposed to inhabit, they captured this lone wolverine.

Whereas a single small, elusive animal can be randomly, unambiguously photographed and then purposefully tracked and captured alive, it is irrational to propose that numerous larger, indigenous animals could somehow escape detection.

Decade after decade, this "Gigantopithecus" remains hidden from scientific scrutiny, despite the presence of ornithologists, botanists, entomologists, archeologists, geologists, park rangers, hikers, campers, fishermen, cell phones, digital cameras, satellite photography, and law enforcement in and throughout the animal's supposed habitat. This just doesn't add up or make any kind of sense.

If you can't eliminate every known food source, and eliminate every known environment where said extinctee existed, they then might not be extinct at all.

Sure, they might not be extinct. That is correct. Now, where is the evidence for their existence?

If Gigantopithecus co-existed with our ancestors, then maybe they managed to find nitches to carve out meager existences... Maybe they've made a living NOT being seen or found, or maybe they were hunted to the point of genetic deprivation, and all died out.

I'm not sure I follow you. Maybe seven-to-nine-foot-tall bipedal apes have "carved out meager existences" adjacent to human culture? If not, why bring up our supposed "ancestral co-existence with Gigantopithecus"? And if so, what niches do you suggest these enormous animals might have occupied?

How could they have been feeding off our detritus, if that is what you're suggesting, without being seen, shot, stabbed, run over, discovered having died from disease, interacted with by biologists, photographed unambiguously, studied, etc.?

And if they "all died out", where are their remains?

Then again, maybe they developed enough intelligence to equate hidden with survival. Primates ARE smart, right?

Yes, gorillas, chimps and orangutans are keenly intelligent -- to the point that when humans come around, even entirely wild populations of these animals will linger in the area, sometimes in plain sight or only partly hidden, because they let their curiosity get the better of them. They don't vanish like ninjas, silent and invisible in the night.

This is partly how primatologists have become aware of all the many species of monkeys, apes and prosimians. You got out and look for them, and there they are.

Maybe they eat their dead, as to destroy all evidence of their existence, maybe they bury their dead, who knows. There's a LOT of wilderness in the world, and primates have proven to be resourceful creatures.

Do they eat the bones, too? All the hard little finger bones, and the teeth? Do you realize how ridiculous that is?

If they bury their dead, where are the remains? Bones, fossils? Do you know anything about archeology or paleontology? Do you understand that excavations and surveys are being done right now, all over bigfoot's supposed habitat? Why are these professionals not turning anything up in the way of bigfoot remains?

I certainly wouldn't argue that we've eliminated every one of their potential food sources, nor have we eliminated every environment in which they could exist.

It's good that you wouldn't argue that, because that would be absurd. There is indeed plenty of potential nutrition and habitat out there to accommodate an animal of bigfoot's description.

The problem is there isn't any reliable evidence that he actually exists.

Maybe declaring that bigfoot or "Gigantopithecus" is extinct, is premature...

Maybe. What makes you suggest such an unlikely scenario?

[Marduk]

Not quite the same: a Lemur isn't a descendant of a human. And depending on how you define extinction, modern coelacanths do show that they never went extinct. The population has continually existed and reproduced, it's just changed. I consider that a meaningful and useful way to discuss the subject.

According to Dr. Martin vice president of academic affairs at The Field Museum and co-author of the research, who has studied primate evolution from many different perspectives for the past 30 years, their 85-million-year-old early common ancestor of the primates probably looked like a primitive, small-brained version of today's dwarf lemur.
http://www.age-of-the-sage.org/evolution/early_primates_evolution.html
;)

[Roboramma]

http://www.age-of-the-sage.org/evolution/early_primates_evolution.html
;)

That doesn't change the fact that Lemurs are not descendants of modern humans. It doesn't even suggest that they are ancestral to us. Whatever that was, it was no more closely related (in the sense of ancestry and decent) to modern Lemurs than it is to us.

[Marduk]

That doesn't change the fact that Lemurs are not descendants of modern humans. .
I didn't say they were.

It doesn't even suggest that they are ancestral to us. Whatever that was, it was no more closely related (in the sense of ancestry and decent) to modern Lemurs than it is to us.

KotA made a statement that was nonsense, I suggested that his statement was as valid as a nonsense statement that I then invented for comparison (I chose lemur because of our lemur like ancestor)

you then came in and correctly pointed out that what I said was nonsense
well done, that was my point
:rolleyes:
http://en.wikipedia.org/wiki/Irony
:D

[Roboramma]

I didn't say they were. But modern Coelacanths are descendants of ancient Coelacanths.

[Marduk]

double post

[Marduk]

But modern Coelacanths are descendants of ancient Coelacanths.

I know that
you know that
KotA thinks its the same fish unchanged by evolution, which is the same as saying that a lemur/ape/chimp/australopithecus/tree shrew is a human being
getting it yet ?
:D

see
The Coelacanth was thought to be extinct, until someone caught one just a few years ago. ...
this (if true) then qualifies
declaring that bigfoot or "Gigantopithecus" is extinct, is premature...
we all know it isn't true, stop telling me, start telling him
;)

[Roboramma]

I know that
you know that
KotA thinks its the same fish unchanged by evolution, which is the same as saying that a lemur/ape/chimp/australopithecus/tree shrew is a human being
getting it yet ?
:D
Actually you have that backward, it's not the same as saying an ape is a human, it's the same as saying a human is an ape. Which it is. It's not the same as saying a human is a lemur, because as I said, lemurs are not ancestral to humans.

A modern Coelacanth is a member of the clade that makes up all Coelacanths, including the extinct ones. A human is a member of the clade that makes up all apes.

What's my point? It makes sense to say Coelacanths aren't extinct. Now, you can also make the argument that those ancient species are extinct, but their descendants do live on.

As for bigfoot, I'm not interested. The thread title interested me, as did the subject that the OP was pretending to talk about, which is why I'm posting about that. If he didn't want a discussion about extinction in general.. well, he shouldn't have pretended to talk about extinction in general.

[Marduk]

Actually you have that backward, it's not the same as saying an ape is a human, it's the same as saying a human is an ape. Which it is. It's not the same as saying a human is a lemur, because as I said, lemurs are not ancestral to humans.
.

Youre still missing the point, my statement about lemurs was supposed to be nonsense,
it wasn't an attempt at explaining evolution and the direction it has been documented to occur in, I am well aware of those facts
but here I'll let PZ Myers explain it to you

"Coelacanth" is a term that refers to an entire order of fish, the Coelacanthiformes. The modern coelacanths are of the genus Latimeria, and none of the ancient fish belong to that genus—it ought to be fairly obvious that Latimeria is clearly distinct from any of the fossil forms if it was assigned to a unique genus. The brilliant creationists who point to Latimeria and claim that it is an example of an unchanging form might want to reconsider; would they also point to a random member of the primate order, say a howler monkey, and announce that it is obvious that all primates for all of their history have been identical?

any more issues with this, like if you'd like to inform him that howler monkeys aren't descendants of humans or something else as equally as time wasting then his email is pzmyers@gmail.com
thanks
:D

[Roboramma]

Youre still missing the point, my statement about lemurs was supposed to be nonsense,
it wasn't an attempt at explaining evolution and the direction it has been documented to occur in, I am well aware of those facts
but here I'll let PZ Myers explain it to you



any more issues with this, like if you'd like to inform him that howler monkeys aren't descendants of humans or something else as equally as time wasting then his email is pzmyers@gmail.com
thanks
:D

The point he is making makes sense: he is countering the creationist argument that Coelacanths haven't changed in millions of years. They have. So, yes, I agree with that.

You suggested that they don't represent something that was thought to be extinct, but then turned out not to be. I am suggesting that they do.
Maybe I misread you, but:
KoA said:
The Coelacanth was thought to be extinct, until someone caught one just a few years ago.
And you replied:
btw your celeocanth reference is a typical mistake made by someone that doesn't know anything about celeocanths, the modern fish is the last in a lineage of a class of the lobe finned fishes, it is not at all similar to its dead relatives, what you did there is like saying "look, see that Lemur, thats a human that is"
Which looks like you're suggesting that he is wrong when he says the Coelacanth was thought to be extinct, and turned out not to be.

Anyway, as I said, maybe I misread you.

[Marduk]

You suggested that they don't represent something that was thought to be extinct.
nope, I said nothing on that at all, I was very clear that the ancient form was extinct
btw your celeocanth reference is a typical mistake made by someone that doesn't know anything about celeocanths, the modern fish is the last in a lineage of a class of the lobe finned fishes, it is not at all similar to its dead relatives, what you did there is like saying "look, see that Lemur, thats a human that is"
Maybe I misread you, .
completely,
I made exactly the same point as PZ Myers, that in comparison to his statement all of the human family tree are identical (irregardless of direction), KotA believes that the Coeleocanth is evolution unchanged (which is a creationist approach), I was just saying that was wrong, nothing else
;)

if you wanted to correct me on something you might have mentioned my perrenial misspelling of Celeocanth
:p

the deja vu here is driving me nuts
take a look
http://forums.randi.org/showthread.php?postid=5359156#post5359156
:D

[Puppycow]

Maybe he's like a Forest Ninja.
sARqCa5Cqu4

[Roboramma]

nope, I said nothing on that at all, I was very clear that the ancient form was extinct Why did you snip the rest of my sentence which read "but turned out not to be"?

[Roboramma]

I made exactly the same point as PZ Myers, that in comparison to his statement all of the human family tree are identical (irregardless of direction), KotA believes that the Coeleocanth is evolution unchanged (which is a creationist approach), I was just saying that was wrong, nothing else
;)

Fair enough, then it comes down to us reading KoA differently. I didn't read him as saying that the Coelacanth was unchanged by evolution (and honestly don't see how you found that in his OP), only that it represents an example of us looking for something, not finding it, and thus assuming it doesn't exist, when in reality it does.
Of course, there's room here for argument over the definition of it, which is the discussion I thought you and I were having.

So, given that context, why did I take issue with your analogy? Because if Lemurs were thought to be extinct, homo sapiens wouldn't be an example that falsified that. But modern Coelacanths do represent an example of the continuation of that lineage which was thought to be extinct.

[Marduk]

Why did you snip the rest of my sentence which read "but turned out not to be"?

imo it was irrelevant to the point I had made, so are you now saying that the Coelacanth which was thought to be extinct, turned out not to be ?
:p
King is talking about a fish, not a species, he isn't aware that the modern fish is quite different to the extinct ones, he doesn't check facts or do research, but relies on assumptions and his feelings

Fair enough, then it comes down to us reading KoA differently. I didn't read him as saying that the Coelacanth was unchanged by evolution (and honestly don't see how you found that in his OP), .

4th post
EXACTLY.

Things HAVE shown back up, after thought to be extinct. That fish with 'leg' looking fins, the "Coelacanth"...
The Coelacanth hasn't shown back up, it is not the same as the extinct form. It evolved from it, perhaps youve been reading a different thread
:p
anyway, pointless continuing this, why don't you start a new thread if your need is that great, personally I am well aware of what evolution is and how it works, thanks

[King of the Americas]

"Just a few years ago"?

They have continued to show up in fishing catches, from what I've heard.

[King of the Americas]

...

Maybe. What makes you suggest such an unlikely scenario?

I don't know about being a likely scenario, but the thing that makes me consider that the might still be around is that there is plenty of environment and potential food stuffs for them to exist upon.

There has to be a cause for an extinction. Like us hunting doo-doo's.

What caused ALL the Gigantopithecus to die off? Were they slow moving tasty treats?

100,000 years ago is the oldest fossil/bone found, which seems like a blink of an eye in evolutionary terms. The chances that THAT fossil/bone was THE last living specimen, are low right?

[EHocking]

Nope.

I was hoping this could be a discussion about environments, food sources, and determining actual extinctions.Since the merging of these two threads, please reread the link I provided in Post 58 (http://forums.randi.org/showpost.php?p=4884547&postcount=58) for a scientific approach to determination of extinction of an organism (posted the last time you raised subject).

[King of the Americas]

...

As for bigfoot, I'm not interested. The thread title interested me, as did the subject that the OP was pretending to talk about, which is why I'm posting about that. If he didn't want a discussion about extinction in general.. well, he shouldn't have pretended to talk about extinction in general.

Extinction 'in general' is exactly what I wanted to talk about.

My cousin is studying at Texas Tech, and last year witnessed the extinction of some sort of fresh water minnow. When I queried how he could be for sure, he said, "Well, a man made lake destroyed the only environment they were known to exist."

He went on to explain how difficult it is to truly wipe out a species, and that 'extinction' isn't a word tossed about haplessly. I immediately thought about what bigfoot eats and where they exist. Neither of which has been eliminated completely.

[King of the Americas]

Since the merging of these two threads, please reread the link I provided in Post 58 (http://forums.randi.org/showpost.php?p=4884547&postcount=58) for a scientific approach to determination of extinction of an organism (posted the last time you raised subject).

"We're sorry...

The item you're looking for cannot be found. It may have been renamed, moved or deleted.

Please double check the web address.

Click here to return to the homepage or use the links on the left to navigate the site.


Thank you."

[EHocking]

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Thank you."Well, since it's been 18 months since you last didn't read it, I'm not surprised.

http://www.ace-eco.org/vol3/iss2/art3/

[Cayvmann]

I immediately thought about what bigfoot eats and where they exist. Neither of which has been eliminated completely.

So, you were thinking about what, something that has never been proven to exist, eats and where they exist? How are you going to prove that it is extinct, if you can never prove that it existed? The leap to say it's a Gigantopithecus doesn't cut it. Prove that one is the other... That would require proving BF exists and mapping the connections.

[Vortigern99]

I don't know about being a likely scenario, but the thing that makes me consider that the might still be around is that there is plenty of environment and potential food stuffs for them to exist upon.

There has to be a cause for an extinction. Like us hunting doo-doo's.

What caused ALL the Gigantopithecus to die off? Were they slow moving tasty treats?

100,000 years ago is the oldest fossil/bone found, which seems like a blink of an eye in evolutionary terms. The chances that THAT fossil/bone was THE last living specimen, are low right?

I spent an hour composing a careful rebuttal to your post -- the opening post of a thread about Gigantopithecus -- and you respond with this? Taking my final sentence out of context and answering the question it poses with a generic, meaningless platitude and uneducated guesses, as though I had never responded to any of your numerous appeals to ignorance and incredulity?

Forget it. I'm finished with your blind, deaf, dumb refusal to educate yourself on subjects you pretend interest you.

[Dinwar]

I don't know about being a likely scenario, but the thing that makes me consider that the might still be around is that there is plenty of environment and potential food stuffs for them to exist upon.

There has to be a cause for an extinction. Like us hunting doo-doo's.

What caused ALL the Gigantopithecus to die off? Were they slow moving tasty treats?

100,000 years ago is the oldest fossil/bone found, which seems like a blink of an eye in evolutionary terms. The chances that THAT fossil/bone was THE last living specimen, are low right?
I'll take over, then. No one else is annoying me right now. :D

The last paragraph actually gets into a touchy subject--first and last appearance datums (FADs and LADs). In paleontology the first and last appearance aren't taken as the origin and extinction of a species, unless there's good reason (say, Chixilub). More typically there's considered a buffer above and below the LAD and FAD, respectively, where the species existed but is not known from the fossil record.

As for the rest, you're exibiting Alvarez Syndrom: You think of extinctions as big, important events. They are not. All an extinction is, is the death of the last organism in a species. Whatever can kill one organism can cause an extinction. You don't need to cause a lack of food, or a horrendous disease, or a bolide impact--just one organism to die. Or, to put it in a soundbite: All species are one generation away from extinction.

He went on to explain how difficult it is to truly wipe out a species, and that 'extinction' isn't a word tossed about haplessly. I immediately thought about what bigfoot eats and where they exist. Neither of which has been eliminated completely.Irrevant. First you need to provide evidence that the thing exists; THEN work on determining its ideal habitat (and even then you're going to have trouble, because "ideal" doesn't mean "all the habitat it can possibly survive in"); THEN work on demonstrating it still exists. And it's not that hard to wipe out a species. Species seem to have finite lifespans--a few million years, and they disapear.

Of course, I'm putting the cart before the horse here. Who wants to define the term "species"? ;)

[ZirconBlue]

"Just a few years ago"?

In KoTA's defense I do recall a "rediscovery" in the news in the past decade or so.

[Dinwar]

The ivory-billed woodpecker?

[SOdhner]

I don't know about being a likely scenario, but the thing that makes me consider that the might still be around is that there is plenty of environment and potential food stuffs for them to exist upon.

If we're not requiring any kind of physicial evidence, this applies to all manner of creatures - both real and imagined. There is plenty of environment and food stuffs to support a species of two-tailed fox. There is plenty of environment and food stuffs to support an isolated group of hominids that resemble Ewoks. Until we have some physical evidence for these things it's pointless to speculate that Ewoks, Two-Tail Foxes, or Bigfoot is out there.

The other thing (and I apologize if this distiction has already been made, I admit I haven't read this whole thread) is that we need to distinguish between the CLASSIFICATION of "extinct" and the factual state of extinction. The first one is a best guess that generally requires that the creature is acknowledged to have existed in the first place and has no confirmed sightings in the last fifty years. This classification is sometimes revoked due to a confirmed sighting, but that doesn't change that it was correct at the time.

In other words, even if you suggest that Gigantopithecus is still alive it is correctly classified as extinct.

(The second one has nothing to do with classification. Something can be physically extinct without being classified as such. This requires simply that all members of the species die off. That's not terribly hard for some animals.)

[CapelDodger]

The dodo were stupid, AND slow, and not very adept.

They were adept enough until we showed up.

Hunting an illusive predator would be tougher, I think.

If you mean something that's elusive and illusory, that certainly would be tricky to pin down.

[Dinwar]

Hunting an illusive predator would be tougher, I think.
Not really. Ever see a short-faced bear? How about a Smiledon? I'm not talking about bones, I'm talking the real living, breathing horror of seeing one of these monsters in the flesh--of turning the corner in a woods and seeing a bear bigger than a polar bear staring at you, or realizing that the teeth on the cat that's trying to eat you are as long and as powerful as the knife you're trying to defend yourself with.

No? I guess elusive predators weren't really that hard to kill off, then, were they?

In actuallity, we likely didn't hunt these predators (or dire wolves, or any of the rest of the beasts that used to occupy my current home). What happens is humans out-compete them for food resources. Large predators generally need large prey to survive efficiently. Humans like to kill and eat large things. The competition drives the predators to less and less efficient foods, until they're eating things which aren't enough to sustain them. Look at what happened with orcas sometime--it's a beautiful example of this process.

Also, bear in mind that predators are really in VERY ecologically precarious possitions. A top predator is eating very inefficient foods, and really has a very poor success rate when it comes to prey capture (5-10% if I recall correctly). They're also highly specialized. Smiledon could only eat large animals--elk, moose, mammoths, and the like. Its teeth were not able to handle smaller prey. Similarly, polar bears can only handle soft, high-nutrient foods--the strain of using their jaws to masticate more robust foods, such as squirrels or rabbits (with all the little bones to crunch), runs the very real risk of breaking bits of the bear's jaw. Even a generally omniverous creator like a brown bear needs a great deal of food to survive. Throwing a highly adaptable, highly omniverous species like humans into the mix does very bad things to top predators, even in the absence of actual hunting of those animals.

The dodo were stupid, AND slow, and not very adept.This is a very common misconception by those who don't understand evolution. Those who DO understand the theory realize that those traites which humans value--speed, agility, intelligence, dexterity, etc--are often completely irrelevant to the survival of the organism. Look at sponges. These are barely even individual organisms; they're sessile detritus feeders, about a half-step up from pond scum. However, they've survived for over half a billion years that I'm aware of. Same with pond scum itself. We're still living in a bacterial world (and could be argued to merely be a bacterial collony, from two different lines of reasoning). On the flip side, the sleek, agile, graceful predators like wolves, jaguars, eagles, and the like are on the very brink of extinction. Many are flat-out gone. Being stupid, being slow, etc. does not make one unfit. Dying off does.

[ZirconBlue]

The ivory-billed woodpecker?

No, I mean a big "OMG we found coelacanths!" story.

[Correa Neto]

Gigantopithecus was a genus composed by some species which different sizes, possibly with different habitats or niches and which lived at different time frames, right?

So, its quite likely there's not a single answer to the question why gigantopithecus no longer exist. There should be an answer for each species.

Please also keep in mind that the genus distribution, based on presently available data, was restricted to parts of Southeast Asia and China. Thus there's no actual need for a big (global or continental) environmental change to cause their extinction.

A few days ago Animal Planet aired here an "After Apocalypse" show (or something like that). They linked Toba eruption to their extinction. Well, IIRC Toba supervolcano KABOOOOM! was ~73Ky ago, while gigantopithecus were around untill ~200Ky. I admit my gigantopithecus sources might be outdated, but if they are correct, they got it quite wrong. Anyone has any new (reliable, please, no bigfoot-related crap) info on the youngest ages of those critters?

http://www.uiowa.edu/~bioanth/giganto.html
http://news.nationalgeographic.com/news/2005/12/1208_051208_giant_ape_2.html

[King of the Americas]

I'll take over, then. No one else is annoying me right now. :D

...

Of course, I'm putting the cart before the horse here. Who wants to define the term "species"? ;)

Thank you very much. I found this informative.

So, if the last known fossil to be found was 100,000 years ago, what are the chances of a sub-species making it another few 10,000 years, or so?

Much has been made of an 'absence of evidence', but what if another species understood the very nature of "evidence", and took it upon themselves to rely on NOT being seen, for their very survival.

I was kicking around this idea of a Blair Witch style video of someone who gets abducted by a BF. Then I heard it had already been done.

When I think about what would be required of a BF if it were to exist, I think there would have to be an extensive nature breeding network, that exists well beyond common humanly trafficked areas. Shade the areas on a map void of cities, streets, roads, and plowed acreage. Then draw lines between the largest of those areas, and last, overlay a map of 'anecdotal' sightings, and see what happens...

[King of the Americas]

I spent an hour composing a careful rebuttal to your post -- the opening post of a thread about Gigantopithecus -- and you respond with this? Taking my final sentence out of context and answering the question it poses with a generic, meaningless platitude and uneducated guesses, as though I had never responded to any of your numerous appeals to ignorance and incredulity?

Forget it. I'm finished with your blind, deaf, dumb refusal to educate yourself on subjects you pretend interest you.

Sorry buddy...

Be well.

[RoboTimbo]

Thank you very much. I found this informative.

So, if the last known fossil to be found was 100,000 years ago, what are the chances of a sub-species making it another few 10,000 years, or so?

Much has been made of an 'absence of evidence', but what if another species understood the very nature of "evidence", and took it upon themselves to rely on NOT being seen, for their very survival.

I was kicking around this idea of a Blair Witch style video of someone who gets abducted by a BF. Then I heard it had already been done.

When I think about what would be required of a BF if it were to exist, I think there would have to be an extensive nature breeding network, that exists well beyond common humanly trafficked areas. Shade the areas on a map void of cities, streets, roads, and plowed acreage. Then draw lines between the largest of those areas, and last, overlay a map of 'anecdotal' sightings, and see what happens...

Don't forget to glue the macaroni on it.

[GeeMack]

Thank you very much. I found this informative.

So, if the last known fossil to be found was 100,000 years ago, what are the chances of a sub-species making it another few 10,000 years, or so?

Much has been made of an 'absence of evidence', but what if another species understood the very nature of "evidence", and took it upon themselves to rely on NOT being seen, for their very survival.

I was kicking around this idea of a Blair Witch style video of someone who gets abducted by a BF. Then I heard it had already been done.

When I think about what would be required of a BF if it were to exist, I think there would have to be an extensive nature breeding network, that exists well beyond common humanly trafficked areas. Shade the areas on a map void of cities, streets, roads, and plowed acreage. Then draw lines between the largest of those areas, and last, overlay a map of 'anecdotal' sightings, and see what happens...


Unfortunately the average believer doesn't appear to have the wherewithal to undertake such a task. It requires both the motivation to get up off the butt and do the work, and the necessary intelligence to understand how to go about it, traits which seem to be in very short supply among the bigfoot/alien faithful.

Don't forget to glue the macaroni on it.


Yes, and the glue.

[Dinwar]

So, if the last known fossil to be found was 100,000 years ago, what are the chances of a sub-species making it another few 10,000 years, or so?Not enough data to know. Is this a common species? If the last articulate brachiopod was 10ka (they're 250ma, but just go with it) I'd say they probably went extinct 9ka. If it's a Isotilus maximus, I'd say it's probably still running around. With human fossils? It's dead.


Much has been made of an 'absence of evidence', but what if another species understood the very nature of "evidence", and took it upon themselves to rely on NOT being seen, for their very survival. Wouldn't matter. First off, most of them DO do this. You don't see many wolves in the woods when you're on a walk. Around California there's bobcat and coyotes, but you can go your entire life without so much as seeing their scat. And I KNOW there are lizards in Ohio that I've never seen (I know what they look like, and I've tried to find them, and I failed). Animals don't like to be found. Fortunately for us, once they die that doesn't matter--a certain percentage are going to die in depositional (or at least preservational) environments, or their remains will be in them. Each time it walks by a river there's a chance of a trace fossil. Each organism that drowns is a potential fossil. Think of how many human corpses we've found from the stone age--these were people every bit as careful and intelligent as we are, that were trying VERY hard to not die (and often just as hard to not be seen).

When I think about what would be required of a BF if it were to exist, I think there would have to be an extensive nature breeding network, that exists well beyond common humanly trafficked areas. Shade the areas on a map void of cities, streets, roads, and plowed acreage. Then draw lines between the largest of those areas, and last, overlay a map of 'anecdotal' sightings, and see what happens... Won't work. Check out the National Geologic Map Database sometime. All those areas have been searched by humans. Geologists, hydrologists, explorers, hikers, etc. go into places that most people consider insane--my favorite places on Earth include mountain ranges that halted armies and deserts with the word "Death" in their name. There simply isn't any area that's not explored.

[Correa Neto]

...snip...
Much has been made of an 'absence of evidence', but what if another species understood the very nature of "evidence", and took it upon themselves to rely on NOT being seen, for their very survival.
...snip...

So, this seems to be KotA newest... uhm... How can I say... Fantasy- Bigfoots (bigfeet, whatever) are the flying saucer's skygods, the ascended lost race from Atlantis. Don't worry. There are reports merging bigfoot and UFO activity. You will not be completely alone in this madness.

Won't work. Check out the National Geologic Map Database sometime. All those areas have been searched by humans. Geologists, hydrologists, explorers, hikers, etc. go into places that most people consider insane--my favorite places on Earth include mountain ranges that halted armies and deserts with the word "Death" in their name. There simply isn't any area that's not explored.

As most other woos, he'll refuse to admit the gaps are too small to hide god, an unknown civilization, UFOs, living dinosaurs, bigfoot, [add woo thingie here]. Scan completely a given area. No [add woo thingie here] found? So what? The [add woo thingie here] just slipped under your nose to somewhere else before you turned you scanner on.

[King of the Americas]

Not enough data to know. Is this a common species? If the last articulate brachiopod was 10ka (they're 250ma, but just go with it) I'd say they probably went extinct 9ka. If it's a Isotilus maximus, I'd say it's probably still running around. With human fossils? It's dead.

Wouldn't matter. First off, most of them DO do this. You don't see many wolves in the woods when you're on a walk. Around California there's bobcat and coyotes, but you can go your entire life without so much as seeing their scat. And I KNOW there are lizards in Ohio that I've never seen (I know what they look like, and I've tried to find them, and I failed). Animals don't like to be found. Fortunately for us, once they die that doesn't matter--a certain percentage are going to die in depositional (or at least preservational) environments, or their remains will be in them. Each time it walks by a river there's a chance of a trace fossil. Each organism that drowns is a potential fossil. Think of how many human corpses we've found from the stone age--these were people every bit as careful and intelligent as we are, that were trying VERY hard to not die (and often just as hard to not be seen).

Won't work. Check out the National Geologic Map Database sometime. All those areas have been searched by humans. Geologists, hydrologists, explorers, hikers, etc. go into places that most people consider insane--my favorite places on Earth include mountain ranges that halted armies and deserts with the word "Death" in their name. There simply isn't any area that's not explored.

Good stuff, thanks.

That said, these and other areas HAVE been searched. While returning without a body, many have returned with reports of BF-ish creatures. Police, hikers, geologists, or just the average Joe Schmoh come back reporting seeing or smelling large bi-pedal beings, on occasion.

What would the the absolute smallest a population of primates could be, without suffering genetic deprivation and die off for that reason?

[RoboTimbo]

Good stuff, thanks.

That said, these and other areas HAVE been searched. While returning without a body, many have returned with reports of BF-ish creatures. Police, hikers, geologists, or just the average Joe Schmoh come back reporting seeing or smelling large bi-pedal being, on occasion.

What would the the absolute smallest a population of primates could be, without suffering genetic deprivation and die off for that reason?

What does an unknown large bi-pedal being smell like?

[King of the Americas]

What does an unknown large bi-pedal being smell like?

"skunk"..., an "unwashed wet animal"...or a Survivor contestant on day 29...

[RoboTimbo]

"skunk"..., an "unwashed wet animal"...or a Survivor contestant on day 29...

So they weren't smelling unknown animals, they were smelling known animals and attributing it to BF?

[King of the Americas]

So they weren't smelling unknown animals, they were smelling known animals and attributing it to BF?

Well...some people claim to have smelled it before seeing it.

That said, I suppose you're right. Smelling something stinky alone would be meaningless.

[Dinwar]

That said, these and other areas HAVE been searched. While returning without a body, many have returned with reports of BF-ish creatures. Police, hikers, geologists, or just the average Joe Schmoh come back reporting seeing or smelling large bi-pedal beings, on occasion. Two things: First, anacdotes aren't proof. And second, "When you hear hoofbeats, think horsie." In other words, the most likely explanation is the most mundane. I know from experience that when someone walks by you in rugged terrain, with a lot of trees, you often don't get a good look at them, and it's easy to misinterpret what you see. This has actually lead to at least one death in my family--a distant cousin thought the brown thing with a small white patch was a deer. Sadly, it turned out to be his father in a hunting coat and tighty-whities answering nature's call. It is MUCH more likely that the "large bi-pedal being" is simply a human.

That said, I suppose you're right. Smelling something stinky alone would be meaningless. Particularly in a woods. There are a lot of animals that could smell pretty bad, alive or dead. And a lot of non-animal things that can have similar odors.

What would the the absolute smallest a population of primates could be, without suffering genetic deprivation and die off for that reason? Somewhere between 2 and infinity. I'm not being facitious here--you're getting into statistics, and that's a tricky subject. The problem is twofold: First, ALL populations are suffering from genetic drift (which is what I think you're talking about). It would take, quite literally, a population of infinite size (along with about 6 other traits) to not suffer that. Second, in smaller populations there's always the chance that nothing bad will happen. It's been speculated that in at least a few cases a single pregnant fruit fly started a whole new species in Hawaii. Animals can go into bottlenecks and come out relatively fine--that's why we call them "bottlenecks" and not "certain death". It's just highly unlikely.

And besides, population size isn't your problem here. The complete lack of fossil evidence is. These areas are VERY closely examined for fossil evidence of large animals in the Quaternary (yeah, yeah, an outdated term--most of the references I work with still use it :P ). No ape remains are found in the Southwestern United States until humans arrive. Even small populations would leave some evidence.

[Correa Neto]

Regarding the minimum number, there's the 50-500 "rule". It is taken by many as a gross underestimation, the actual number being an order of magnitude higher according to them. 50 for short tem species survival, 500 for long term.

It gives, however, some general guidelines.

First fo all, its for a population, not the entire species. It means the specimens must be somehow in contact and allowd to breed. If they are scattered in 50 groups of 10 specimens with no contact between the groups, then the species is on the road to nowhere.

Second, its an estimate (if I understood it properly) for the number of breeding specimens, it will not include those too young, too old, too sick or just to lowly in the group status to breed.

The estimate will change according to breeding habits and hazzard factors such as loss of offspring to diseases, predation, etc. Small species with numerous offspring which stay for a small time under parental care clearly have an edge regarding large animals which give birth to a single cub, pup, whatever, each separated by a long time interval and requiring a long tendering time.

To sum up- things do not look good for the usual "small population" excuse for the absence of specimens.

http://www.sciencedaily.com/releases/2009/10/091013104344.htm
http://www.snre.umich.edu/~dallan/nre220/outline12.htm

[Dinwar]

Interesting. Do you remember off-hand how small the human population got about 100ka? I know we went through a serious bottle-neck (the whole human species would fit inside a small sports arena).

[Correa Neto]

No, I'm not that old...:duck:














Sorry, could not resist.

I had the 2K and 5K figures in my head, for whatever reason. If Wikipedia is to trust, the estimates are between 3K to 10K surviving individuals. The links on the 50-500 rule point to ~2K as the number of specimens required for comfortable survival odds. Not sure how many individuals would be considered as able to breed, but the overall human population would perhaps be above the level we are talking about (assuming all these estimates are correct), but I doubt all these folks would be in touch. Most likely in isolated groups scattered around Africa, Asia and Europe. But here enter factors which can not be applied to other species- our brains, our culture and our technology give our species an edge regarding colonizing the world and increasing population which can be rivalled only by cockroaches.

[Dinwar]

The 2k-5k range sounds like what I remember hearing about. As far as I can recall, we were mostly still in Africa at that time, or perhaps just starting to spread outward. That said, even there the populations would have serious issues when it came to interbreeding (the whole rift-valley thing, for example, and inevitable tribal conflicts creating Montegue/Capulet style standoffs [we see similar issues in all kinds of other mammals]). So generally we were well above the minimum, but too close for comfort.

And, it should be pointed out, we have evidence for a population that small, in a seismically active area (you don't get much more active than a continent ripping itself apart). Which means finding bigfoot remains on a bajada or playa lake bed in the desert, or in stream channel deposits in alpine woodlands, shouldn't be terribly difficult if they existed.

[King of the Americas]

Great info guys, thanks!