JREF Homepage Swift Blog Events Calendar $1 Million Paranormal Challenge The Amaz!ng Meeting Useful Links Support Us
James Randi Educational Foundation JREF Forum
Forum Index Register Members List Events Mark Forums Read Help

Go Back   JREF Forum » General Topics » Science, Mathematics, Medicine, and Technology
Click Here To Donate

Notices


Welcome to the JREF Forum, where we discuss skepticism, critical thinking, the paranormal and science in a friendly but lively way. You are currently viewing the forum as a guest, which means you are missing out on discussing matters that are of interest to you. Please consider registering so you can gain full use of the forum features and interact with other Members. Registration is simple, fast and free! Click here to register today.

Tags aliens , evolution , intelligence

Reply
Old 20th November 2012, 12:35 AM   #1
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
The Man In A Suit - Alien Evolution

I have a question...

I am sure you're all familiar with the classic sentient alien depicted in science fiction - a humanoid in some sort of suit to make them look odd.

I've heard people remark that statistically, the odds of a sentient alien species resembling humans even a little bit is very very small.

I wonder about this. Rather, I would argue that the prerequisite characteristics necessary to enable the emergence of higher intelligence dictate that any life form developing higher intelligence on another planet would necessarily resemble humans.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:56 AM   #2
SezMe
post-pre-born
 
SezMe's Avatar
 
Join Date: Dec 2003
Location: Santa Barbara, CA
Posts: 18,471
I see no reason why they could not resemble terrestrial octopi, for example.
SezMe is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:13 AM   #3
Mojo
Mostly harmless
 
Mojo's Avatar
 
Join Date: Jul 2004
Location: Nor Flanden
Posts: 25,380
Originally Posted by gumboot View Post
I would argue that the prerequisite characteristics necessary to enable the emergence of higher intelligence dictate that any life form developing higher intelligence on another planet would necessarily resemble humans.

Why?
__________________
"You got to use your brain." - McKinley Morganfield

"The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky
Mojo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:13 AM   #4
Mikemcc
Graduate Poster
 
Join Date: Dec 2009
Posts: 1,103
I think we can say for sure that exoskeltons are out unless they develop in wildly different gravity, extreme low g has issues with atmosphere retention long enough for evolution. While it's possible that invertibrates such as an octopus related creature could develop intelligence, I believe that it could only be tool wielding in an environment that supports it's body (such as in the ocean).

It's level of symmetry is likely to be a function of it's environment, a highly predatory environment is likely to favour creatures with 360 degree vision, but you may then lose other senses, like depth perception. I too think that it will have a symmetry similar to ours, though numbers of limbs, digits, layout and mechanisms of limbs may well be different.
Mikemcc is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:20 AM   #5
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by SezMe View Post
I see no reason why they could not resemble terrestrial octopi, for example.
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:45 AM   #6
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by Mikemcc View Post
I think we can say for sure that exoskeltons are out unless they develop in wildly different gravity, extreme low g has issues with atmosphere retention long enough for evolution. While it's possible that invertibrates such as an octopus related creature could develop intelligence, I believe that it could only be tool wielding in an environment that supports it's body (such as in the ocean).

It's level of symmetry is likely to be a function of it's environment, a highly predatory environment is likely to favour creatures with 360 degree vision, but you may then lose other senses, like depth perception. I too think that it will have a symmetry similar to ours, though numbers of limbs, digits, layout and mechanisms of limbs may well be different.

The number of limbs is a good example to draw on. Given the importance of tool-use in developing intelligence, it seems pretty much a given that any animal attaining higher intelligence needs to at least have one set of "spare" limbs for manipulating tools. Let's call them "arms". I say spare, because the evolution of chimpanzees suggests that advanced tool use only emerges once a pair of limbs can be dedicated full-time to the task (chimpanzees will use tools locally, but as they are normally quadrupedal they don't transport their tools around with them, discouraging them from putting time and effort into making more complex tools to keep).

Limbs are also the most efficient and effective way of achieving locomotion on land, so it stands to reason any higher-intelligence organism will also require limbs for travel. Let's call them legs.

The question is, then, how many?

What's crucial about limb development is the configuration has to be established fairly early in the organism's evolution, long before it starts using tools (it starts using tools because it can, it doesn't evolve limbs so it can use tools). So we have to look at alternative benefits to those limbs. And remember, once the limbs reach a level of complexity, evolution is going to work against the emergence of new limbs because those will have to arise first as simple proto-limbs, which won't offer any tangible benefit to an organism that already has developed limbs.

So we have to ask where limbs came from.

Well, they came from pectoral fins on primitive fish. They provided maneuverability and buoyancy in water. Additional sets of limbs emerging further alone the spine offer no advantage as they lie within the shadow of the leading limbs (much like the reason multiple ranks of wings on aircraft don't work).

So at the early stage of vertebrate development we're pretty locked into a single pair of limbs. Once they start venturing out of water only having two limbs isn't ideal; the tail drags on the ground causing friction which slows the creature down and can cause injury. Even basic proto-limbs offer a benefit by slightly elevating a part of the tail, thus slightly reducing contact with the ground. Each subsequent enlargement of the proto-limb increases the benefit. By this method you gradually develop a second pair of limbs.

But what about three or four pairs of limbs? Well, they don't offer any advantage. You only need four limbs. An organism with one pair of developed limbs and one pair of proto-limbs is actually at an advantage over an organism with two pairs of proto-limbs because both gain the advantage of an elevated body, but one does it more efficiently, only having to supply energy to one pair of limbs.
Once the second pair are in place any additional proto-limb pairs are just hanging around in mid air, offering no advantage whatsoever. On the other hand those little appendages offer disadvantages. For one it's tissue/muscle/bone requiring energy, for no benefit. So the animal is less efficient. Secondly, the protrusions offer places the animal can be seized, or can get caught on things; endangering it, again for no benefit.

Thus a third or fourth pair of proto-limbs is a net evolutionary loss, and never develop.

That's why any advanced land-based life-form will be bipedal with four limbs.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:51 AM   #7
McHrozni
Illuminator
 
Join Date: Jun 2009
Posts: 4,691
Originally Posted by gumboot View Post
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.
Human brain is different in organization to that of any other animal. We process information in very small, highly specialized centers, as opposed to spreading it around a large portion of the cortext. It's quite significant even if you compare just human to chimpanzee.

I would assume it's a highly unlikely thing to evolve, metabolically expensive and all that.

McHrozni
McHrozni is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:10 AM   #8
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by McHrozni View Post
Human brain is different in organization to that of any other animal. We process information in very small, highly specialized centers, as opposed to spreading it around a large portion of the cortext. It's quite significant even if you compare just human to chimpanzee.

I would assume it's a highly unlikely thing to evolve, metabolically expensive and all that.

McHrozni


Yeah, this seems to be supported by the fact that our higher intelligence evolved so late. We were using basic tools possibly as early as 4 million years ago, and started making stone tools about 2 million years ago. Yet the very earliest proto-langauge might have emerged as late as 600,000 years ago, only really became developed 100,000 years ago, and we only began displaying behaviour of modern man 50,000 years ago.

In other words, it seems our higher intelligence came only after we'd stepped ourselves outside the evolutionary rat race. We were no longer competing with other species for survival. Once we had no threats other than our selves, we could dedicate more resources to enlarging our brains and less to surviving. Our bone and muscle structure dropped dramatically as our intelligence started to take over from brute strength. That reduction in bone and muscle mass meant, for our size, much more of our food could go to our brain, letting it develop even further.

From that point brain power develops incredibly quickly, and before you can blink you're sitting at a computer trying to filter out the fake Britney Spears porn from the real stuff.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:11 AM   #9
StankApe
Banned
 
Join Date: Oct 2012
Posts: 4,643
The main problem with your hypothesis is that we can't assume earthlike gravity. We ca't assume carbon as the basis for the lifeform either. The environmental differences could be fairly dramatic.

A planet that exists in the so called "Goldilocks Zone" may be similar to earth, yet have a much higher gravity due to a heavier core. Or it could have only 30% of it's surface covered in water. Or be a completely saltwater planet .Or could have a slightly different atmospheric chemistry yet all of these environments would be capable of producing life .

Minute variables could have dramatic long term evolutionary affects on a lifeform. Heck, every mass extinction, every climactic event has lead humans to this point. If any of those things change. It could have been octopi that were the pinnacle of sentience on the planet. or some other form of life. We made it here cuz it just worked out that way.
StankApe is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:31 AM   #10
McHrozni
Illuminator
 
Join Date: Jun 2009
Posts: 4,691
Originally Posted by StankApe View Post
The main problem with your hypothesis is that we can't assume earthlike gravity. We ca't assume carbon as the basis for the lifeform either. The environmental differences could be fairly dramatic.
From what we know of chemistry, the most likely way for life to form would be along carbon and water basis we see on Earth. Other structural atoms and solvents are possible, but this one appears to be most favorable. In other words, as far as our knowledge goes, different life forms might use different systems elsewhere, but would most likely be limited to only the most basic forms.
Of course the whole definition of life comes into play not long after.

Quote:
In other words, it seems our higher intelligence came only after we'd stepped ourselves outside the evolutionary rat race. We were no longer competing with other species for survival. Once we had no threats other than our selves, we could dedicate more resources to enlarging our brains and less to surviving. Our bone and muscle structure dropped dramatically as our intelligence started to take over from brute strength. That reduction in bone and muscle mass meant, for our size, much more of our food could go to our brain, letting it develop even further.
Evolutionary speaking, developing intelligence was a real game-changer, akin to several cells specializing to create a life form where each cell did only a portion of the whole work. Come to think of it, it's the same pattern that gets repeated at least twice more: our brain got specialized in the same way, with small, specialized centers for complex tasks. It happened again in division of labor among humans, where people specialized for some tasks, no longer everyone was hunting and gathering, but you get farmers, warriors, builders, weavers, animal herders, smiths, clerks, telephone cleaners, science fiction cartoon writers and more.
Interestingly, three huge changes in human (and Earth) evolutionary history are actually just one big change repeating itself three times. It's a hugely unlikely change, and always a major game-changer, seeing as how it took billions of years to go from single cells to multicellular organisms that colonized all habitats within a few hundred million years, ten times less. Intelligence, as you noted, was a faster process still, and division of labor even faster. Evolutionary, in a blink of an eye.

McHrozni

Last edited by McHrozni; 20th November 2012 at 02:38 AM.
McHrozni is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:50 AM   #11
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by StankApe View Post
Minute variables could have dramatic long term evolutionary affects on a lifeform. Heck, every mass extinction, every climactic event has lead humans to this point. If any of those things change. It could have been octopi that were the pinnacle of sentience on the planet. or some other form of life. We made it here cuz it just worked out that way.

Yes but there's no necessity that any organism is sentient, neither that only one can be sentient. Given how dramatically different our cognition is from even Chimpanzees, it suggests the circumstances that allows that sort of sentience is extremely narrow.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:24 AM   #12
Halfcentaur
Philosopher
 
Halfcentaur's Avatar
 
Join Date: Jun 2010
Location: Oklahoma City
Posts: 6,644
I've often thought this myself, and I wouldn't be surprised if it's true. I used to think a lot about things life as we know it could end up looking like based on convergent evolution. We see certain traits across wide gaps in relation between species being shared based on certain niches they've similarly adapted to exploit. For instance, most all aquatics probably will have fin/paddle like appendages, assuming appendages for instance are common, whether it's a mammal, a reptile, a fish, or an insect.

Of course we don't know these things, but if life takes very similar directions for whatever reason, perhaps a bipedal animal with a pair of hands and binocular vision is part of what causes animal intelligence to share a reality similar to the one we perceive and navigate mentally.

It's something I would think fascinating to see explored in science fiction as an excuse for a place like Star Wars or Star Trek but with more depth.

Last edited by Halfcentaur; 20th November 2012 at 06:25 AM.
Halfcentaur is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:27 AM   #13
Halfcentaur
Philosopher
 
Halfcentaur's Avatar
 
Join Date: Jun 2010
Location: Oklahoma City
Posts: 6,644
I'd guess tool use and the activity of thinking about tools as an item with a purpose and a use and a function are probably integral to evolving an intelligence like our own which uses concepts like purpose and function as a frame of reference for our entire perception.

Last edited by Halfcentaur; 20th November 2012 at 06:28 AM.
Halfcentaur is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:34 AM   #14
Roboramma
Philosopher
 
Roboramma's Avatar
 
Join Date: Feb 2005
Location: Shanghai
Posts: 7,687
Originally Posted by gumboot View Post
That's why any advanced land-based life-form will be bipedal with four limbs.
So where do elephants fit into your ideas?

ETA: it seems to me that any species that begins tool use is one which will potentially evolve toward greater tool use, and whatever appendage is used for that tool use can be picked up by natural selection and change over time in such a way that it may become better at that task

Crows, for instance, can make and use tools with their feet and beaks, they are not "bipedal with four limbs", but it's possible over deep time for the crow's beak to evolve into a more adept tool using appendage, were the selection pressures to happen to exist in the right way
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov

Last edited by Roboramma; 20th November 2012 at 06:38 AM.
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:45 AM   #15
Roboramma
Philosopher
 
Roboramma's Avatar
 
Join Date: Feb 2005
Location: Shanghai
Posts: 7,687
Originally Posted by gumboot View Post
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.
What makes you think they've "stopped"? All life is constantly evolving, it's possible that some other animals are evolving greater intelligence, while others are evolving toward a more minimalist model that conserves resources, or one that puts them to use elsewhere

Your sentence could be re-written "All animals other than blue whales seem to have hit a sort of size 'ceiling' in their evolutionary path, stopping at what is, by blue whale standards, a very small size", yet there's nothing particularly informative here: the only aspect of that sentence that I know to be true is that the blue whale is the largest animal on earth, but others may be evolving greater or lesser size, I don't see evidence of any ceiling anywhere (actually there are size ceilings, but there's no general ceiling that the blue whale somehow passed that all other animals hit, rather there are specific reasons why each animal is the size that it is, and the same applies to intelligence)



Quote:
Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?
Would they? Perhaps if it were free, but brains cost energy and material to build and maintain, things that can be spent on other body parts or activities
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 07:38 AM   #16
Mojo
Mostly harmless
 
Mojo's Avatar
 
Join Date: Jul 2004
Location: Nor Flanden
Posts: 25,380
Originally Posted by gumboot View Post
The number of limbs is a good example to draw on. Given the importance of tool-use in developing intelligence, it seems pretty much a given that any animal attaining higher intelligence needs to at least have one set of "spare" limbs for manipulating tools. Let's call them "arms". I say spare, because the evolution of chimpanzees suggests that advanced tool use only emerges once a pair of limbs can be dedicated full-time to the task (chimpanzees will use tools locally, but as they are normally quadrupedal they don't transport their tools around with them, discouraging them from putting time and effort into making more complex tools to keep).

Limbs are also the most efficient and effective way of achieving locomotion on land, so it stands to reason any higher-intelligence organism will also require limbs for travel. Let's call them legs.

The question is, then, how many?

What's crucial about limb development is the configuration has to be established fairly early in the organism's evolution, long before it starts using tools (it starts using tools because it can, it doesn't evolve limbs so it can use tools). So we have to look at alternative benefits to those limbs. And remember, once the limbs reach a level of complexity, evolution is going to work against the emergence of new limbs because those will have to arise first as simple proto-limbs, which won't offer any tangible benefit to an organism that already has developed limbs.

So we have to ask where limbs came from.

Well, they came from pectoral fins on primitive fish. They provided maneuverability and buoyancy in water. Additional sets of limbs emerging further alone the spine offer no advantage as they lie within the shadow of the leading limbs (much like the reason multiple ranks of wings on aircraft don't work).

So at the early stage of vertebrate development we're pretty locked into a single pair of limbs.

Well, actually, we're locked into two pairs of limbs because that's what the first land vertebrates had, evolved from the pectoral and pelvic fins of lobe-finned fishes.

But this limitation only applies to vertebrates on this planet. There's no convincing reason that land animals on another planet would have had to evolve from a vertebrate ancestor with four limbs.

Quote:
But what about three or four pairs of limbs? Well, they don't offer any advantage.

Unless you happen to be an insect or a spider. Some arthropods have even more.
__________________
"You got to use your brain." - McKinley Morganfield

"The poor mystic homeopaths feel like petted house-cats thrown at high flood on the breaking ice." - Leon Trotsky
Mojo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 09:14 AM   #17
dlorde
Philosopher
 
dlorde's Avatar
 
Join Date: Apr 2007
Posts: 6,201
Originally Posted by gumboot View Post
All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.
That's a strange way to look at things. One might as well wonder why all animals other than giraffe have hit a neck-length ceiling, or why animals less intelligent than dogs aren't more intelligent than they are...

E.T.A. oops! - Roboramma got there first

What makes you think octopi would 'irrefutably' benefit from even greater intelligence? A valuable trait in one environmental niche is not necessarily as valuable in others; individual 'benefit' in terms of natural selection is being more successful in producing viable offspring than others of your species. Greater intelligence comes at a significant energy cost, so its advantages must outweigh those costs before it becomes a selective advantage. The cost/benefit balance point varies between environments.
__________________
Simple probability tells us that we should expect coincidences, and simple psychology tells us that we'll remember the ones we notice...

Last edited by dlorde; 20th November 2012 at 09:26 AM.
dlorde is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 09:15 AM   #18
dlorde
Philosopher
 
dlorde's Avatar
 
Join Date: Apr 2007
Posts: 6,201
Originally Posted by McHrozni View Post
Human brain is different in organization to that of any other animal. We process information in very small, highly specialized centers, as opposed to spreading it around a large portion of the cortext. It's quite significant even if you compare just human to chimpanzee.
Do you have any links or references for that ? (because I don't think it's correct)
__________________
Simple probability tells us that we should expect coincidences, and simple psychology tells us that we'll remember the ones we notice...

Last edited by dlorde; 20th November 2012 at 09:36 AM.
dlorde is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 09:40 AM   #19
dlorde
Philosopher
 
dlorde's Avatar
 
Join Date: Apr 2007
Posts: 6,201
Originally Posted by Mojo View Post
Quote:
But what about three or four pairs of limbs? Well, they don't offer any advantage.
Unless you happen to be an insect or a spider. Some arthropods have even more.
There are also plenty of mammals that use their tails as an extra limb, so could be said to have 5 limbs.
__________________
Simple probability tells us that we should expect coincidences, and simple psychology tells us that we'll remember the ones we notice...
dlorde is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 10:28 AM   #20
Cayvmann
Muse
 
Cayvmann's Avatar
 
Join Date: Mar 2009
Posts: 702
Originally Posted by gumboot View Post
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.
I think you equate further evolution with higher intelligence. Intelligence may very well become a hindrance to evolution/survival, and my decline in a healthy ( for it's environment ) species. Intelligence is just one strategy for survival. It might also lead us to blowing ourselves out of existence or developing a germ that wipes us out, because of our curiosity...

An alien species might not look like us, and it may have become dominant and even interplanetary with lesser intelligence but a better social strategy.
Cayvmann is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 11:29 AM   #21
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by Roboramma View Post
So where do elephants fit into your ideas?
I presume you're talking about the trunk? What about it?


Originally Posted by Roboramma View Post
ETA: it seems to me that any species that begins tool use is one which will potentially evolve toward greater tool use, and whatever appendage is used for that tool use can be picked up by natural selection and change over time in such a way that it may become better at that task.
Only where the appendage can be dedicated to tool use. If we take an elephant's nose, for example, it is used for a range of essential activities, including drinking water. This prevents the trunk becoming a dedicated tool device.


Originally Posted by Roboramma View Post
Crows, for instance, can make and use tools with their feet and beaks, they are not "bipedal with four limbs", but it's possible over deep time for the crow's beak to evolve into a more adept tool using appendage, were the selection pressures to happen to exist in the right way
Except that, like an elephant's trunk, a bird's beak has other essential uses which prevents it developing into a dedicated tool-user.

It's only once an animal has genuinely spare appendages dedicated to tool use that the animal will benefit from taking time and effort to manufacture tools to carry around with it.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 11:36 AM   #22
George152
Master Poster
 
George152's Avatar
 
Join Date: Jun 2002
Location: Hamilton New Zealand
Posts: 2,387
Originally Posted by gumboot View Post
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.
If the Octopi lived as long as we do there is no reason as to why their intelligence couldn't match ours.
Dolphins use toys and tools
__________________
Unemployment isn't working
George152 is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 11:56 AM   #23
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by Mojo View Post
Well, actually, we're locked into two pairs of limbs because that's what the first land vertebrates had, evolved from the pectoral and pelvic fins of lobe-finned fishes.
My understanding is that the earliest ancestors of tetrapods only had bones in the pectoral fins, not their pelvic fins. Maybe I'm mistaken.


Originally Posted by Mojo View Post
But this limitation only applies to vertebrates on this planet. There's no convincing reason that land animals on another planet would have had to evolve from a vertebrate ancestor with four limbs.
I've explained why; it's a matter of efficiency. A second set of limbs offers a distinct advantage over one pair. A third doesn't offer a significant advantage over two.



Originally Posted by Mojo View Post
Unless you happen to be an insect or a spider. Some arthropods have even more.
They only offer an advantage because they're so small. A high number of legs enables maneuverability in extremely rough terrain (such as walking up walls, etc). To a very small animal such as a spider or insect even relatively flat land is full of obstacles that are enormous relative to the animal (plants, rocks, etc).
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:06 PM   #24
SezMe
post-pre-born
 
SezMe's Avatar
 
Join Date: Dec 2003
Location: Santa Barbara, CA
Posts: 18,471
Originally Posted by dlorde View Post
Do you have any links or references for that ? (because I don't think it's correct)
I second this question because I, too, don't think it is true. For example, processing of the signals sent from the retinas is done in several different parts of the brain which, in total, comprise about a third of the brain mass.
SezMe is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:12 PM   #25
The Shrike
Master Poster
 
The Shrike's Avatar
 
Join Date: Nov 2009
Location: USA
Posts: 2,613
Originally Posted by gumboot View Post
It's only once an animal has genuinely spare appendages dedicated to tool use that the animal will benefit from taking time and effort to manufacture tools to carry around with it.
Interesting idea, but how do you define "spare" limbs? I don't have to be using my hands every minute of the day to ensure my survival, so they are spare? How is that different from me not using my feet every minute of the day because I am often sitting down?

In which of the following Hominid genera would you consider the hands to be spare appendages?

Pan
Gorilla
Australopithecus
Homo
Ardipithecus
The Shrike is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:29 PM   #26
Turgor
Critical Thinker
 
Join Date: Jan 2010
Location: Amsterdam
Posts: 363
Originally Posted by gumboot View Post
Only where the appendage can be dedicated to tool use. If we take an elephant's nose, for example, it is used for a range of essential activities, including drinking water. This prevents the trunk becoming a dedicated tool device.
Do you use your hands when you drink water? If not, please describe the method you use to drink water.
Turgor is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:34 PM   #27
theprestige
Penultimate Amazing
 
Join Date: Aug 2007
Posts: 11,837
Ugh. This thread sums up everything I hate about Pop Evolution: Look at a single case of how things are, invent some plausible Just So Story of why, and promptly conclude that How Things Are is How Things Must Be.
theprestige is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:36 PM   #28
Guybrush Threepwood
Trainee Pirate
 
Guybrush Threepwood's Avatar
 
Join Date: Jun 2007
Location: An Uaimh
Posts: 1,826
Originally Posted by Turgor View Post
Do you use your hands when you drink water? If not, please describe the method you use to drink water.
He probably lies down by the stream and drinks directly from it, so should be put to death at once.

As for the rest of the OP I suspect alien intelligent life might be so different from us that we spend decades arguing about whether it really is alive or conscious, rather than going straight up to it and shaking hands while marvelling that they have seven fingers.
Guybrush Threepwood is online now   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:50 PM   #29
dlorde
Philosopher
 
dlorde's Avatar
 
Join Date: Apr 2007
Posts: 6,201
Originally Posted by SezMe View Post
I second this question because I, too, don't think it is true. For example, processing of the signals sent from the retinas is done in several different parts of the brain which, in total, comprise about a third of the brain mass.
The structural differences between human and other primate brains are relatively small, mainly consisting of greater numbers of cortical neurons. The assertion that the human brain is different in organization to that of any other animal is trivially true, but the difference is not significantly greater than one would expect, given the evolutionary relationships. See the summary to Myth #4 here.

Unless there is some well hidden research, I know of nothing to support McHrozni's assertion about significant differences in processing. If there is some, I'd be really interested to see it.
__________________
Simple probability tells us that we should expect coincidences, and simple psychology tells us that we'll remember the ones we notice...
dlorde is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 12:52 PM   #30
dlorde
Philosopher
 
dlorde's Avatar
 
Join Date: Apr 2007
Posts: 6,201
Originally Posted by The Shrike View Post
Interesting idea, but how do you define "spare" limbs?
Quite; and what about the case of various monkeys, where use of a prehensile tail frees up the lower limbs for tasks other than hanging on?
__________________
Simple probability tells us that we should expect coincidences, and simple psychology tells us that we'll remember the ones we notice...
dlorde is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:14 PM   #31
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by The Shrike View Post
Interesting idea, but how do you define "spare" limbs? I don't have to be using my hands every minute of the day to ensure my survival, so they are spare? How is that different from me not using my feet every minute of the day because I am often sitting down?
The limbs have to be free to be dedicated to tool use, as I said. If the limbs are utilised for locomotion, you can't transport tools long distances, which discourages development of more complex tools.


Originally Posted by The Shrike View Post
In which of the following Hominid genera would you consider the hands to be spare appendages?

Pan
Gorilla
Australopithecus
Homo
Ardipithecus

Pan and Gorilla are quadrupeds, Australopithecus and Homo are bipeds, and Ardipithecus is thought to have been something of an intermediate between the two, I believe - with scientists suggesting it was a quadruped in the trees but had altered enough physically that it could travel short distances bipedal.

Or, in other words, only Australopithecus and Homo have spare limbs.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:23 PM   #32
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by Turgor View Post
Do you use your hands when you drink water? If not, please describe the method you use to drink water.
I can drink water with one hand, leaving the other free to carry my tools (that actually raises another point, while tool use only requires one limb, making tools requires two).
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 01:37 PM   #33
gumboot
lorcutus.tolere
 
gumboot's Avatar
 
Join Date: Jun 2006
Location: New Zealand
Posts: 24,676
Originally Posted by George152 View Post
If the Octopi lived as long as we do there is no reason as to why their intelligence couldn't match ours.
Do you mean an actual octopus, or a theoretical octopus-like creature?



Originally Posted by George152 View Post
Dolphins use toys and tools
Yes, they do.
__________________

O xein', angellein Lakedaimoniois hoti têde
keimetha tois keinon rhémasi peithomenoi.


A fan of fantasy? Check out Project Dreamforge.
gumboot is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:15 PM   #34
quadraginta
What was the question?
 
quadraginta's Avatar
 
Join Date: May 2009
Location: Central Vale of Humility
Posts: 9,379
Originally Posted by gumboot View Post
While some octopi demonstrate remarkable intelligence, it's still not even remotely close to the sort of intelligence seen in great apes, let alone humans.

All animals other than humans seem to have hit a sort of cognition "ceiling" in their evolutionary path, stopping at what is, by human standards, a very basic level of intelligence.

Octopi certainly benefit from their intelligence, and they would irrefutably benefit enormously from even greater intelligence. Why hasn't it developed?

There seems to have been something special about our evolutionary position that enabled us to break through the ceiling.

Using homo sapiens is a relatively limited snapshot of evolutionary history to base such broad assumptions upon.

A couple hundred thousand years is an eye-blink to geological history. A very small one. There's an awful lot of hubris involved in assuming our eye-blink is somehow definitive.
quadraginta is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 02:20 PM   #35
Roboramma
Philosopher
 
Roboramma's Avatar
 
Join Date: Feb 2005
Location: Shanghai
Posts: 7,687
Originally Posted by gumboot View Post
I presume you're talking about the trunk? What about it?




Only where the appendage can be dedicated to tool use. If we take an elephant's nose, for example, it is used for a range of essential activities, including drinking water. This prevents the trunk becoming a dedicated tool device.
People use their hands to drink water too, and don't need to move and drink at the same time, so we (and an elephant) can put down our tools to drink and pick them up again when we leave

As I said, the same applies to an elephant

As to requiring two spare limbs to make tools: that's simply not true, your argument for requiring spare limbs only applies to having a limb to hold the tool during locomotion, to doesn't suggest that an elephant couldn't use it's trunk and feet to make tools (ever seen the video of the crow bending a wire into shape to get stuff out of a jar (something like that)? It uses it's beak to hold the wire and it's feet to help bend it in shape


Quote:
Except that, like an elephant's trunk, a bird's beak has other essential uses which prevents it developing into a dedicated tool-user.
There's nothing in evolution that suggests an appendage can't be used for multiple purposes: I can use my mouth to eat and breathe, and manipulate tools (and I do)

Quote:
It's only once an animal has genuinely spare appendages dedicated to tool use that the animal will benefit from taking time and effort to manufacture tools to carry around with it.
Aside from what I said above, you're clearly not considering all the possibilities: what about an animal with a pouch like a kangaroo? It could use it's feet to make and use tools and put them in it's pouch when it's on the move
__________________
"... when people thought the Earth was flat, they were wrong. When people thought the Earth was spherical they were wrong. But if you think that thinking the Earth is spherical is just as wrong as thinking the Earth is flat, then your view is wronger than both of them put together."
Isaac Asimov
Roboramma is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:02 PM   #36
I Ratant
Penultimate Amazing
 
I Ratant's Avatar
 
Join Date: Apr 2008
Posts: 18,700
One of the classic stories...
http://en.wikipedia.org/wiki/Mission_of_Gravity
I Ratant is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 06:13 PM   #37
Reivax
Thinker
 
Reivax's Avatar
 
Join Date: Jan 2011
Location: Australia
Posts: 230
You may find this interesting. The idea that a dinosaur may have reached extreme intelligence if they were not wiped out.
__________________
You will find easily
More than sufficient doubt
That these colours you see
Were picked in advance
By some careful hand
With an absolute concept of beauty
Reivax is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 07:47 PM   #38
Delvo
Illuminator
 
Delvo's Avatar
 
Join Date: Jul 2008
Location: Harrisburg, Pennsylvania
Posts: 4,869
Alien life would still have to live with the same laws of physics and chemistry that we have, so evolution can be expected to follow some of the same tracks, especially in cases in which Earth lineages unrelated to each other ended up with similar traits.

Intelligence is useless to a life form that doesn't move around. For that matter, intelligence requires a brain, which is a development of the nervous system, and even THAT doesn't exist in life forms that don't move around. Movement favors bilateral symmetry and cephalization.

Because of a short oxygen supply compared to the atmosphere and a lack of workable building/toolmaking materials, it's not really plausible for a species to get technological if it lives under water. Also, a brain that's going to get technological has to have some minimum size that can't be a whole lot less than ours, because creating lots of complex interactions between neurons requires having lots of neurons to interact. So, let's bring our cephalized, bilaterally symmetrical critter out of the water and onto dry land and make it a size that can carry a suitable brain. Then something interesting happens with the limbs. The more a body is under the influence of gravity, whether because of coming on land or because of being large, the better it is to have a small number of large limbs instead of a large number of small ones. (That's not just a theory but an observation of what has actually happened separately in more than one case.) So a land animal big enough to have anywhere near the kind of brain we're looking for would probably have the minimum number of pairs of limbs it can get away with and still be functional on land. The same basic physical reason why we built devices with three feet or more, it wouldn't be very practical for an animal to have less than three limbs, at least not for animals that are just coming out of the water for the first time: it would be unstable when standing up and draggy if sprawling out. That makes the practical lower limit two pairs instead of one.

Re-orient the body and learn to balance on one pair while using the other pair for something else, and then, *POOF*, you've got what some might call a humanoid alien: two legs, two arms mounted higher up on the body, and a head on top... quite likely even breathing and eating through the same opening like us because of another established rule we know of in nature that old openings get hijacked for new functions more often/easily than new openings get created. Also, in a critter on the ground, eyes belong on top, so they'll probably be higher than the mouth even after the descendants are standing up straight later.

What that doesn't give any reason to expect the aliens to have in common with us is any of our particular proportions (ratios of sizes between one part and another), or ears on the sides of the head, or a nose like ours.
Delvo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 09:00 PM   #39
GraculusTheGreenBird
Thinker
 
GraculusTheGreenBird's Avatar
 
Join Date: Apr 2004
Posts: 132
Well, except the assumption is that oxygen is needed for life underwater, which is pretty specific to metabolism of life on earth, and not even all earth life. Other planets could have completely different forms of life, completely different biology underwater, and plenty of materials available for tool making.

We also still have an anthropomorphic assumption that lighter fluids like gas is somehow necessary for life, which I dont think is true. It makes just as much sense for example, to think of an alien spacecraft filled with a dense liquid as it does with air, they are both self contained environments needed to protect the life from vacuum when travelling through space.

And regarding the earlier comment that animals will larger number of legs tend to be smaller, as their extra legs help them navigate more bumpy terrain, I don't really buy that. My understanding was that arthropods seem to have reached a size limit due to their respiration method, rather than anything else. There have been plenty of huge insects in the past, and we have large spiders and centipedes now.

Also, why do we assume that intelligence has to be embodied in a physically large form, or a size similar to ours? It seems that primates brains needed to reach a particular size to enable our intelligence to flourish, but under a different planetary biology, that size might be completely different.

So why not a hand size intelligent insect or fish equivalent, or organisms based around sets of three limbs? Seems just as likely to me.

Last edited by GraculusTheGreenBird; 20th November 2012 at 09:01 PM. Reason: typos
GraculusTheGreenBird is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Old 20th November 2012, 09:08 PM   #40
Delvo
Illuminator
 
Delvo's Avatar
 
Join Date: Jul 2008
Location: Harrisburg, Pennsylvania
Posts: 4,869
Originally Posted by Mojo View Post
Well, actually, we're locked into two pairs of limbs because that's what the first land vertebrates had, evolved from the pectoral and pelvic fins of lobe-finned fishes.
Originally Posted by gumboot View Post
My understanding is that the earliest ancestors of tetrapods only had bones in the pectoral fins, not their pelvic fins. Maybe I'm mistaken.
It was both. That's where our pelvises and legs came from. There's also a third pair of bony, muscular fins in at least some, behind the pelvic fins, called anal fins. (I'm skipping the lower caudal fins here because of structural differences from the three pairs.) But fish with all three pairs did not colonize land, or at least not with competitive success.

Similarly, in arthropods, the group that's most successful on land is the one with the fewest limbs (6), the second-most successful group on land has the second-fewest (8), and the third-most successful group on land, which is actually mostly found in water or going back & forth between land and water, has the third-fewest (10+). Of the two groups with the most limbs, retaining them on every segment, the one that came onto land has been the arthropods' least numerous, least diverse, and most ecologically restricted group (centipedes & millipedes), while the one that stayed in the water was the opposite of that until a mass extinction (trilobites).

The only molluscs to colonize land are molluscs with no limbs (snails & slugs, no octopuses or squid or nautiluses).

Among animals on land, even if you exclude vertebrates and just stick to arthropods, there's also an inverse connection between size and limb count, although it's looser than the above pattern.

The general rule is that the burden of supporting & propelling the body is inversely related to limb count; more burden calls for fewer limbs (at least down to 4 because 2 is a special case because it's less than the minimum for the tripod effect), whether the added burden happens due to coming out of the water or due to growing large. The reasons have to do with proportional surface area touching the ground and proportional limb size.

Originally Posted by Mojo View Post
There's no convincing reason that land animals on another planet would have had to evolve from a vertebrate ancestor with four limbs.
I don't recall seeing it said that anything has to happen here. But there are good reasons to expect some outcomes be be more likely, and more common in the real universe, than others.

Originally Posted by gumboot View Post
I presume you're talking about the trunk? What about it?

... If we take an elephant's nose, for example, it is used for a range of essential activities, including drinking water. This prevents the trunk becoming a dedicated tool device.
When we started using our hands for tools, we were also still using them for locomotion, maybe not when on the ground, but at least in trees. They were never spare. Their use just shifted, including a time that they were used for both functions. Tools may even have been what caused them to be diverted away from locomotion. Similarly, if we are to postulate something like alien elephants using their trunks (and presumably also tusks) for tools, then it makes sense to postulate that those would also end up serving two or more purposes for a while, possibly later to be followed by dropping the non-tool-related functions if there's a conflict.
Delvo is offline   Quote this post in a PM   Nominate this post for this month's language award Copy a direct link to this post Reply With Quote Back to Top
Reply

JREF Forum » General Topics » Science, Mathematics, Medicine, and Technology

Bookmarks

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 05:07 AM.
Powered by vBulletin. Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
© 2001-2013, James Randi Educational Foundation. All Rights Reserved.

Disclaimer: Messages posted in the Forum are solely the opinion of their authors.