Mass Extinction

[Hegel]

Many people claim that the mass extinctions caused by humans are bad things. While I could understand an aesthetic viewpoint, I have yet to see any convincing evidence of ecological dangers. After all, contrary to what many people say, we have survived many mass extinctions before. For example at the end of the Permian? Era there was a mass extinction that killed off an estimated 99% of the species diversity on Earth. With in a few million years the diversity bounded back. So what is different about mass extinctions caused by humans?

[arcticpenguin]

Quote:

Originally posted by Hegel
After all, contrary to what many people say, we have survived many mass extinctions before. For example at the end of the Permian? E

What you mean we, Kimosabe? I don't know about you, but I wasn't around back then. Some ancestors of mine survived, I'm pretty sure, but they weren't human back then.

If you check into the details of the various maxx extinctions, you'll find that large land animals fare poorly. If the entire ecosystem collapses, what will "we" live on? And if a few humans survive somewhere, what good does that do me unless I'm one of them?

[Iamme]

When mass extinctions come to mind, we think of Flood, meteor...or perhaps a nuclear holocaust.

But what if there were a disease spread of more than Bubonic Plague proportions? What if there was some infectious disease for which no known antibiotic could cure. What if it killed off all the top researchers? What if....aaaaeeeeee....it's scary to think about. I heard on the news today about some infectious bacteria (or whatever) that antibiotics can't cure, and this has the sports world concerned, as this will affect how they handle showers, shared towels, and a host of things.

[fishbob]

99 to 1 ?

You like those odds?

[Hegel]

Quote:

Originally posted by fishbob
99 to 1 ?

You like those odds?

No, of course not. Seems reasonable now. We're worried about humans going extinct. I've heard people talk about the threat of ALL life going extinct, which I think is fairly ridiculous, but it seems reasonable to try to have humans survive. Thanks for the answers.

[a_unique_person]

Life will survive in some form on this planet, even if we set off all the nukes. However, the higher order life, like ours, might be having some problems.

Yes, it will bounce back, over millions of years. However, you seem to be implying that because there have been mass extinctions on this planet, one more caused by us doesn't really matter.

Using this logic, if we see a person who has fallen over and hurt themselves, it doesn't really matter if we then kick them a few times in the ribs. They fall over anyway.

[athon]

I get your drift, but consider it this way:

A) Moral Argument - we have an obligation as organisms with the ability to use forsight to not cause suffering to other organisms.

B) Ecological Argument - Causing such a massive adverse effect on our ecosystems will in turn affect our way of life, causing hardships that would otherwise not have to be dealt with.

C) Sociological Argument - Just because some societies exploit their resources, why should that decide the way other societies live? i.e. one society might rely on fish to survive on, to worship or to use in erotic mating rituals: if another society brings that fish to extinction, why should the other social group suffer for it?

I'm sure there are many others. These are three to start with.

Athon

[a_unique_person]

There is a similar debate over in Politics.

I have been trying to make the point that our morality should not necessarily be what decides what happens in the world at large. It is something that we have created, and really applies to us as such. The idea that we should just care for nature because we might benefit from it is a little self centred.

[Prospero]

Originally posted by athon

Quote:

A) Moral Argument - we have an obligation as organisms with the ability to use forsight to not cause suffering to other organisms.

The primary problem with moral arguments is that not everyone follows the same set of morals. Whereas you might feel obligated to assist a species that plays an inconsequential role in the food chain and fills a very specific, though unnecessary, ecological niche, I feel no such obligation. I'm specifically thinking of a species of snail of which there are currently 5 members left and for which they have blocked off 5 surrounding miles of untouched land in what would otherwise be a thriving commercial area.

Quote:

B) Ecological Argument - Causing such a massive adverse effect on our ecosystems will in turn affect our way of life, causing hardships that would otherwise not have to be dealt with.

In the case of killing off, as an example, algae or phytoplankton or crickets or mice, there would indeed be a very serious backlash to the entire food chain and result in our way of life more than likely suffering (especially the algae, seeing as it provides the oxygen that we all breathe). Lesser species, the bald eagle being one, will fade into obscurity and their position at the top of the food chain will be replaced by some other bird of prey and mankind will be completely unaffected.

Quote:

C) Sociological Argument - Just because some societies exploit their resources, why should that decide the way other societies live? i.e. one society might rely on fish to survive on, to worship or to use in erotic mating rituals: if another society brings that fish to extinction, why should the other social group suffer for it?

That's the beauty of a society: your society's welfare is the primary concern. Other societies can suck eggs for all you care. Yes, it is rather rude to leave an entire society without their pescafilic needs fulfilled, but, unlike the fish species, they can adapt and survive.

[PygmyPlaidGiraffe]

I watched the BBC yesterday on this seemingly extensive

study

Quote:

"We are in the middle of a sixth extinction event that began about 50,000 years ago"

how do they know we are in the middle? Is it because we are about halfway through a thawing cycle between Ice Ages? If so, then is this really the 6th major extinction? It could be oh I don't know, the sweet 16th.

Quote:

The butterfly may be a good indicator for what is happening to the other insects.

why is the butterfly considered a good indicator species?

[Wrath of the Swarm]

Quote:

Originally posted by Prospero
The primary problem with moral arguments is that not everyone follows the same set of morals. Whereas you might feel obligated to assist a species that plays an inconsequential role in the food chain and fills a very specific, though unnecessary, ecological niche, I feel no such obligation.

Whereas you might feel obligated not to hunt down and kill people to harvest their internal organs, I feel no such obligation.

[Dylab]

Larely in respone to an article that expressed a similar view to Hegel's, Stephen Jay Gould wrote a essay in his book Six Little Piggies that discusses this issue and tries to create an ethic for enviromentalistism. He ultimately argues that the only reason why we have conservationism is purely for the sake of humanity. He did such a good job that I can't imagine any other arguments against Hegel's post so forgive me for paraphrasing the essay.

What ultimately is wrong with the idea is a confusion between two different perspective ideas on rates. The time periods in the Geologic rate completely dwarves the entire existance of civilization. The time that ultimately is meaningful is to us is just a moment compared to the history of the earth. Saying that something might ultimately be a improvement or is insignific in geologic time is meaningless because that is ultimately something we don't place value in.

Obviously if a species goes extinct then nature won't be affected. Eventually new species will rise to take its place and the variety of life will stay the same. But we won't be there to see it happen. Any science we can gain from it is loss and any sense of wonder and any appreciation children and adults might get will be lost also. I'm guessing it is somewhat less likely but there might me more pragmatic effects on us as well.

I don't see any other arguments for enviromentalists. Obviously we are going to change stuff on this planet. How can we argue any effect is significant without using our own values?



Mmm... Having reread this post and the thread, I don't this this post really addresses the issue. I also did a terrible job summarizing Gould's essay. But I really liked his thoughts and I think it is something that I wish more enviromentalist groups would pick up.

[Dymanic]

Quote:

Originally posted by Dylab

What ultimately is wrong with the idea is a confusion between two different perspective ideas on rates. The time periods in the Geologic rate completely dwarves the entire existance of civilization.

Extinction can happen fast. An organism which took many millions of years to evolve can be pushed over the brink in a few generations. There is no way to ever know what has been lost when that happens. The DNA of every organism contains the results of millions of years of painstaking biological R&D, and any one is a potential treasure trove of useful information -- it isn't just about having cool stuff for the zoo. I think people who make statements like this:

Quote:

Whereas you might feel obligated to assist a species that plays an inconsequential role in the food chain and fills a very specific, though unnecessary, ecological niche, I feel no such obligation. I'm specifically thinking of a species of snail of which there are currently 5 members left and for which they have blocked off 5 surrounding miles of untouched land in what would otherwise be a thriving commercial area.

might be inclined to change their minds if they came to a better appreciation of the potential commercial value of that information.

[espritch]

There is also an aesthetic argument. One good reason (IMHO) to preserve the diversity of life on this planet, it that it is beautiful. I am endlessly fascinated by the wonderful diversity of life and I think the world will be a much poorer place if we destroy it all for short term gain. The worth of things cannot always be measured in terms of economic utility or mere survival.

It is true that life will probably rebound in few million years, but neither I nor you will be around to see it. It would be a much better idea to invest some effort in preserving the diversity that we already have.

[neutrino_cannon]

Quote:

Originally posted by Hegel
Many people claim that the mass extinctions caused by humans are bad things. While I could understand an aesthetic viewpoint, I have yet to see any convincing evidence of ecological dangers. After all, contrary to what many people say, we have survived many mass extinctions before. For example at the end of the Permian? Era there was a mass extinction that killed off an estimated 99% of the species diversity on Earth. With in a few million years the diversity bounded back. So what is different about mass extinctions caused by humans?

The permian extinction was interesting, in that it did kill off a whole lot of stuff, but it made a whole lot of opourtunity.

Oh, and as for the diversity bouncing back in a few million years, tell that to a paleontologist working in the lystrosaurus zone of the karoo. It's a formation right after the permian mass extinction, and it's called the lystrosaurus zone for a reason.

There's nothing but bloody lystrosaurs.

The permian mass extinction did clear the way for the cynodont's though, and for that I'm glad, and so should be all of you.

Except for articpenguin, who is still bitter over the evolution of whales and seals in the eocene,without which his kin would compete with only the plotopterids.

[SquishyDave]

I always wanted to know about species that were going extinct anyway. I heard that the hairy nosed wombat has been going extinct slowly for ages, but humans scamper around trying to save it, when without our intervention it would be no more anyway.

Saving this animal may well increase our impact on nature, and that's bad right?

[Dylab]

Quote:

Originally posted by SquishyDave
Saving this animal may well increase our impact on nature, and that's bad right? [/b]

Why?

[SquishyDave]

Quote:

Originally posted by Dylab
Why?

Well I don't think so, but that's what conservationists want isn't it? Less impact on nature? So by saving species willy nilly without a thought to animals that just might be on the way out is messing with nature, and they don't want that, do they?

My view is, if it's on the way out anyway, and we must be sure it's on the way out, what obligation do we have to save it? I don't see much of one, we might hang on to a few in zoos coz they are cute and we don't like to lose something forever as humans, but extinction is a part of life.

[neutrino_cannon]

There is justification for concern over human impact on the environment.

To begin, frogs and crocodiles are getting hit, hard. As I recall, we may have driven one species of frog over the edge lready. Why is this significant? Because frogs and crocodiles are not supposed to go exticnt, ever.

At the end of the Cretaceous period, the dinosaurs, the pterosaurs, the mosasaurs the plesiosaurs, the pliosaurs, the ammonites, several lineages of toothed birds and a few other more obscure lineages went extinct in what in geological terms is the blink of an eye. The frogs and crocodiles, however, were next to unaffected (one of the reasons the asteroid hypothesis doesn't make much sense).

There are K strategists, like rhinos and elephants and whales, which take care of one youngster and focus a lot of energy into it. There's the foil stratergy, R strategists. These animals put energy into churning out lots of young so that at least one has a good chance of reaching adulthood. R strategists, like rats roaches and such are very much harder to kill off.

The dinosaurs, from what we know of their nests (quite a bit actually) and bone texture were R strategists par excellance. Even the largest sauropods laid huge clutches, as evidenced by well preserved nests of titanosaurs from Patagonia.

So, if what killed off the dinosaurs, which were adaptable and very fast reproducing beasts, was not able to kill of pond turtles, frogs and crocodiles, why are we?

The recent wave of pleistocene extinctions is a compicated event. In North America, there is evidence that the climatic changes that changed the flora had a drastic effect on the megafauna of the time. Also, several lineages went extinct several hundred thousand years before humans got to the americas, so they died on their own. In several other cases though, butchery sites, folsam spear points in mammoths and the like, it is appearant that people were hunting the large mammals very effectively indeed. Large mammals are almost always K stategists, and since the fossil record is only a small percentage of what actually went on, one can readily imagine that paleo indians driving a thousand Bison antiquis off of a cliff on a regular basis drove their numbers down beyond their reproductive capacity.

Elsewhere, however, the picture is far clearer. In Australia, New Zealand, New Calidonia, Madagasgar, Hawaii and several other islands in the carribean and mediterranean, the arrival of humans coincides with the extermination of all the large ground animals, especially flightless birds, and in many cases severe enivironmental changes. In Hawaii, the local avifauna is about 80% extinct and the local flora isn't doing a whole lot better. All of this is directly attributable to human action.

Humans, and the pets and parasites they take along with them unitentionally (Rats in Hawaii that eat the eggs of native birds) or intentionally (Mongeese in Hawaii that were supposed to eat the rats, but don't and eat the local birds instead) are incredibly destructive, especially to island habitats. We wiped the steller's sea cow out within twenty-seven years of it's descovery.

Extinction is a fact of life, but right now the amount going on is far beyond background levels, and it's happening in animals that generally are not affected by mass extinction events. While there are species whose demise we certainly had nothing to do with (e.g. phorusrhacids), there are others we clearly killed off, or other we pushed close to the brink and are now slowly on the way out.

The actions of paleo indians are doubtless blameless, they had to eat something, and I sincerely doubt they knew the recklessness of their actions. We, however, do know what impact we have, and are now at a crossroads. If we value biological diversity, which has furnished us with countless medicines, mechanical inspirations, and just plain beauty, then it is now that we can try to preserve what's left.

When the very first people came to Australia, the dogs they brought with them (unintentionally, the evidence seems to show IIRC) brought the thylacines to their knees, and eventually out of existence in Australia. Oops. In Tasmania however, where the humans were docile and remarkable in technological (they couldn't start fires), the thylacines lived on. If the settlers had been able to interpret the fossil record, the rock paintings of thylacines in Australia, and the fact that thylacines really didn't have that big of an impact on sheep, they could have easily kept the magnificent beast from being reduced into a dictionary entry.

[Dymanic]

Quote:

Originally posted by SquishyDave

Well I don't think so, but that's what conservationists want isn't it? Less impact on nature?

You must be thinking of the 'Prime Directive' in the old Star Trek series. I wonder if there is any conservationist who believes that non-intervention is a realistic policy considering how many of us there are now. Like it or not, our role is now that of custodianship, and the problem is that many species are running out of time while we complete our on-the-job training.

[SquishyDave]

Quote:

Originally posted by Dymanic
You must be thinking of the 'Prime Directive' in the old Star Trek series. I wonder if there is any conservationist who believes that non-intervention is a realistic policy considering how many of us there are now. Like it or not, our role is now that of custodianship, and the problem is that many species are running out of time while we complete our on-the-job training.

I didn't say conservationists wanted no intervention, I said they wanted less impact on nature, other than that I agree with you, we must manage as best we can to keep nature as happy as possible, without compromising too badly on our ablity to exploit natural resources as we must for our advancement. Through luck and evolution it's our world for now, and it's just plain stupid to crap in your own kitchen.