Don’t talk to aliens, warns Stephen Hawking

[dan2100]

I hate to oversimplify, but if aliens can reach us from any stretch of intra-galactic or inter-galactic realms, they've got their shit together.

How we might fit into their agenda, only time will tell.

~ Shane

Any chance that "time" will be in the next 20-odd years?

Geez, I guess not.

I read an essay recently by an anthropologist opining that due to fundamental similarities among all Earthly animal life, aliens would likely be 'quite' similar to what we consider normal humans.

(Unless they are silicon - based, or something, I think his theory has a high degree of probability.)

I'd like to read that article. And what is the degree of similarity of animal life on Earth? Think of the full range of animal life, from jellyfish and loriciferans to bees, octopodes, and humans. Yeah, they all have DNA, but there's a wide range of behavioral and morphological differences.

Given the range of animal life on Earth and how the likely evolution could've taken different paths, I find it hard to believe there'd be many physical or physiological similarities between intelligent life elsewhere in the universe. Even if, as some might think, there might be some overall similarities in minds -- say, if we were to find to have intelligence and reason, one must have something like the mammalian emotions and child rearing -- that doesn't tell us much else about ET.

They would have to be highly rational, surely, which lends a whole new meaning to Universality of principle.

Alien Objectivists? Don't rule it out!

Tony

I wouldn't rule it out, but I think there might be differences that are relevant.

[tjohnson]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

[Dragonfly]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

In two words: convergent evolution.

[Christopher]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

Are you neglecting the importance of the middle finger in human communication?

Hrrmmmmmmm... ok, more seriously: the suggestion is that brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

[dan2100]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

I don't know if you're right -- that fine motor control is the sine qua non for having a "highly technological race." But let's say it is. Well, it appears thatr elephants and octopodes have fine motor control. (Both elephants and octopodes have high celphalic quotients -- supposedly, a decent general rough measure of intelligence.) Isn't it possible that, under the right conditions, their descendents might evolve into "highly technological" beings very unlike humans. If you just mean, too, that an intelligent alien life form would have to have a complex brain-like organ, this doesn't tell us much. Octopodes have complex brains, but they seem very unlike humans -- while still being animals.

And what about substitutes for "highly evolved circuitry in the brain." Think of humans. They actually seem to have smaller brains than Neanderthals -- both tool users -- but might make up for this via complex societies. (Of course, arguments about Neanderthals run both ways: they had bigger brains, but maybe lacked certain modules or complexities. Also, had Neanderthals survived and humans went extinct, then perhaps they would've developed agriculture, complex societies, and discussions about the Fermi Paradox. Perhaps a Neanderthal GS would be arguing about this and pointing out that humans had such small brains that they couldn't have possibly made a complex technological society.)

Your arguments always seem to be the same here: they've got to be like humans because humans are like humans. Again, too, generalizing from one example leads to problems like this.

[dan2100]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

Are you neglecting the importance of the middle finger in human communication?

Hrrmmmmmmm... ok, more seriously: the suggestion is that brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

Yes, if the path must be -- and there's no reason it must be -- from high res control to tool use to complex technological societies capable of talking to other ones across the galaxy, then it seems like this would be a wide path that might include things like tentacles, trunks, or even more bizarre means of such fine control.

It might also give pause to consider brain evolution in mammals -- presuming this has something to do with human intelligence and technology. If we somehow knew nothing about humans, but just knew some basic "facts" about brain size and complexity and their supposed relationship to intelligence -- and presumed that intelligence leads to technological civilization and were looking at animal evolution from about, say, 50 million years ago to 10 million years ago, we might never have guessed a group of primates would win the race. We might see things like the rather steady increase in cetacean (the order under which whales and dolphins are places) and proboscideans (the order under which elephants are places) and made an educated guess that if technological civilizations were to be had, they would come from future members of these orders -- rather than from primates. And we'd probably have patted ourselves on the back until mabye about 3 million years ago -- at which time we'd start to note that certain primate lines were taking off in terms of brain size and complexity.

Let's take this logic off world. Imagine there are several tens of thousands of Earth-like planets with life on them. Out of those, how many would necessary evolve something like tool-using former tree-dwellers that think and act much like humans and invent the kind of technology humans now have? How many might take a radically different path and end up with similar technology, but a radically different body plan, physiology, and behavior? (Yes, how many of these planets might never end up with technological civilizations at all, but those are precisely the end states we're not focusing on here.)

[tjohnson]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

In two words: convergent evolution.

LOL, I was not familiar with that formulation.

[tjohnson]

I don't know if you're right -- that fine motor control is the sine qua non for having a "highly technological race." But let's say it is. Well, it appears thatr elephants and octopodes have fine motor control.

Excuse me?? When was the last time you saw an elephant sewing some clothes, for example?

[tjohnson]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

Are you neglecting the importance of the middle finger in human communication?

Hrrmmmmmmm... ok, more seriously: the suggestion is that brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

Actually, it goes back even further - to when our ancestors were able to walk on 2 limbs. Now we had 2 limbs free to do other things - like make and use tools. Also it isn't simply "utility-based interaction with the environment" its something that leads to increased survival like the ability to get more food.

[dan2100]

Did you know that the evolution of our cerebral cortex is related to having opposable thumbs? If an alien life form is a carbon based, protein in water type of life then it would most likely have to evolve similarly. For example, you would not expect to see a highly technological race that does not have fine motor control of their limbs like humans. They would also need highly evolved circuitry in the brain (cortex) and language including mathematics. I can think of many reasons why aliens would be similar to us.

Are you neglecting the importance of the middle finger in human communication?

Hrrmmmmmmm... ok, more seriously: the suggestion is that brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

Actually, it goes back even further - to when our ancestors were able to walk on 2 limbs. Now we had 2 limbs free to do other things - like make and use tools. Also it isn't simply "utility-based interaction with the environment" its something that leads to increased survival like the ability to get more food.

But that observation should make you a bit more humble about the paths life might evolve something technological like current humans, no? The sort of pre-adaptation for hand use -- if indeed this was the path taken -- might have not happened or happened in a very different way. (There's some controversy that walking on two limbs might have happened because some primates used two limbs to move about in trees rather than walk on the ground. To me, much of this looks like arguing much from very little evidence. Surely, this guesses are informed by fossil finds and, hopefully, some understanding of animal locomotion, but I wonder if we revisit this debate in ten years there'll be a raft of other explanations for even this seemingly simple trait.)

Also, note that you've widened or made more vague your criterion: from opposable thumbs to "something that leads to increased survival like the ability to get more food." That could be a many different things -- presumbly almost anything. Were you betting on this, would you put up your retirement account and your kids' or grandkids' college funds into the pot?

[tjohnson]

Yes, if the path must be -- and there's no reason it must be -- from high res control to tool use to complex technological societies capable of talking to other ones across the galaxy, then it seems like this would be a wide path that might include things like tentacles, trunks, or even more bizarre means of such fine control.

It might also give pause to consider brain evolution in mammals -- presuming this has something to do with human intelligence and technology. If we somehow knew nothing about humans, but just knew some basic "facts" about brain size and complexity and their supposed relationship to intelligence -- and presumed that intelligence leads to technological civilization and were looking at animal evolution from about, say, 50 million years ago to 10 million years ago, we might never have guessed a group of primates would win the race. We might see things like the rather steady increase in cetacean (the order under which whales and dolphins are places) and proboscideans (the order under which elephants are places) and made an educated guess that if technological civilizations were to be had, they would come from future members of these orders -- rather than from primates. And we'd probably have patted ourselves on the back until mabye about 3 million years ago -- at which time we'd start to note that certain primate lines were taking off in terms of brain size and complexity.

Let's take this logic off world. Imagine there are several tens of thousands of Earth-like planets with life on them. Out of those, how many would necessary evolve something like tool-using former tree-dwellers that think and act much like humans and invent the kind of technology humans now have? How many might take a radically different path and end up with similar technology, but a radically different body plan, physiology, and behavior? (Yes, how many of these planets might never end up with technological civilizations at all, but those are precisely the end states we're not focusing on here.)

I'm sure you have seen some of the wild and crazy creatures invented in SF movies etc. Whenever I see one I say to myself "what kind of environment did they evolve in that would result in those features giving them adaptive advantage?" Well humans have the highest proportion of cerebral cortex to total brain size which is why are heads are so big. We have to be born at 9 months because if it took any longer our heads wouldn't fit through the birth canal. Our nervous systems continue to develop into our 20's, possibly longer. If I was looking at an alien planet and trying to guess which species was going to become technological I would definitely be looking at the size of the cortex. You mentioned brain size but it not simply brain size - some animals have huge brains, it's the ratio of cortex to brain size that is important. The question is what leads to evolution of cortical brain tissue? I believe it started with tool use and more recently language use.

[dan2100]

I don't know if you're right -- that fine motor control is the sine qua non for having a "highly technological race." But let's say it is. Well, it appears that elephants and octopodes have fine motor control.

Excuse me?? When was the last time you saw an elephant sewing some clothes, for example?

They motor control might not rival humans, but what of their potential descendants? What about on another world with organisms with something like elephants' trunks or octopodes tentacles (and the brain power behind control these)?

Also, turn back the clock about 200,000 years. There's no evidence, despite human ancestors using tools that they were, at that time, "sewing some clothes." I'd hate to see the GS science investigation of nearby planets. I could see the team landing, finding no evidence of opposable thumbs, and moving on, missing, perhaps, a sentient race of tool-users that just happen to look more like octopodes than people. When chewed out on returning to base, I could just hear the team leader telling her or his boss, "But we didn't see they sewing clothes!"

[dan2100]

Yes, if the path must be -- and there's no reason it must be -- from high res control to tool use to complex technological societies capable of talking to other ones across the galaxy, then it seems like this would be a wide path that might include things like tentacles, trunks, or even more bizarre means of such fine control.

It might also give pause to consider brain evolution in mammals -- presuming this has something to do with human intelligence and technology. If we somehow knew nothing about humans, but just knew some basic "facts" about brain size and complexity and their supposed relationship to intelligence -- and presumed that intelligence leads to technological civilization and were looking at animal evolution from about, say, 50 million years ago to 10 million years ago, we might never have guessed a group of primates would win the race. We might see things like the rather steady increase in cetacean (the order under which whales and dolphins are places) and proboscideans (the order under which elephants are places) and made an educated guess that if technological civilizations were to be had, they would come from future members of these orders -- rather than from primates. And we'd probably have patted ourselves on the back until mabye about 3 million years ago -- at which time we'd start to note that certain primate lines were taking off in terms of brain size and complexity.

Let's take this logic off world. Imagine there are several tens of thousands of Earth-like planets with life on them. Out of those, how many would necessary evolve something like tool-using former tree-dwellers that think and act much like humans and invent the kind of technology humans now have? How many might take a radically different path and end up with similar technology, but a radically different body plan, physiology, and behavior? (Yes, how many of these planets might never end up with technological civilizations at all, but those are precisely the end states we're not focusing on here.)

I'm sure you have seen some of the wild and crazy creatures invented in SF movies etc. Whenever I see one I say to myself "what kind of environment did they evolve in that would result in those features giving them adaptive advantage?" Well humans have the highest proportion of cerebral cortex to total brain size which is why are heads are so big. We have to be born at 9 months because if it took any longer our heads wouldn't fit through the birth canal. Our nervous systems continue to develop into our 20's, possibly longer. If I was looking at an alien planet and trying to guess which species was going to become technological I would definitely be looking at the size of the cortex. You mentioned brain size but it not simply brain size - some animals have huge brains, it's the ratio of cortex to brain size that is important. The question is what leads to evolution of cortical brain tissue? I believe it started with tool use and more recently language use.

Actually, I did mention that earlier -- #31 where I wrote of "celphalic quotients." This was, by the way, the wrong term. The correct term is "encephalization quotient." And my point was and remains that "encephalization quotient" over long spans of time was higher and on an upward trend in cetaceans and proboscideans -- if the fossil record is to be trusted -- for a long time and that the primate leap over them might look like a blip on the radar and not a foregone conclusion. (Encephalization is a bit more trickier than brain size -- it's a brain to body mass ratio.)

You should also be careful in looking for a cortex. That might only be something that only indicates intelligence in mammals. You'd be stuck looking for mammal-like organisms on other worlds. Birds and octopodes have very different brain structures; they don't really have cortexes. And were you to look for them in these animals and to confuse having a cortex with being intelligent, you might expect all birds and all octopodes to be about as smart as garden slugs -- which would fly in the face of observations of some pretty intelligent behavior in both birds and octopodes.

[Peter]

Christopher wrote:

. . . brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

End quote

Convergent evolution has an interesting sound to it. I remember reading that *eyes* developed independently, hundreds of times, throughout earth’s history, but wings for flight, only a few times.

Dan Ust wrote:

Let's take this logic off world. Imagine there are several tens of thousands of Earth-like planets with life on them.

END QUOTE

I can imagine that Dan. I remember that Asimov and Sagan both postulated that life would develop in most solar systems, and intelligent life in a percent of solar systems among billions and billions of galaxies.

I have never appreciated the “opposing thumb” theory of human evolution. “Smarter people survived to procreate” is better. With genetics it is inevitable that smarter people will be born without another ice age to wean out the dumb weaklings.

Peter

[dan2100]

Christopher wrote:

. . . brain evolution follows the ability to use tools, so an alien blob which could operate stuff in an environment would also develop likewise. Therefore, it seems that thumbs are not the issue so-much as opportunity for utility-based interaction with the environment. That could come with anything (physical, etc.) that has high-resolution control.

End quote

Convergent evolution has an interesting sound to it. I remember reading that *eyes* developed independently, hundreds of times, throughout earth's history, but wings for flight, only a few times.

I don't know about "hundreds of times" and it depends on what you mean by "eyes." Often people use them to mean any light-detecting systems which seems a very wide definition of eye. Others will define them more narrowly to mean light-detecting systems that image, in which case these evolved probably far fewer times independently -- I believe maybe a half dozen to a dozen times.

Dan Ust wrote:

Let's take this logic off world. Imagine there are several tens of thousands of Earth-like planets with life on them.

END QUOTE

I can imagine that Dan. I remember that Asimov and Sagan both postulated that life would develop in most solar systems, and intelligent life in a percent of solar systems among billions and billions of galaxies.

I meant, of course, in this galaxy.

I have never appreciated the "opposing thumb" theory of human evolution. "Smarter people survived to procreate" is better. With genetics it is inevitable that smarter people will be born without another ice age to wean out the dumb weaklings.

Peter

Many years ago, I got into a discussion of "uplifting." Uplifting is taken some living thing and making it sentient. While discussing this, someone said something along the lines of, 'What good would it be for a pig to be uplifted to human-level intelligence? It doesn't have hands, so it wouldn't be able to use all that intellectual power.' I pointed out that such an intelligent pig -- some pig, for real -- would be able to plan, trade, further cooperate, communicate, and even do things like farm. I even asked my interlocutor to consider if some mad scientist were to remove hands from humans, would this mean they wouldn't be able to use their minds. (This , of course, doesn't mean controlling the thumb might not have lead to some increases in intelligence and so forth, but it seems to me like there are many paths to the top of the mountain -- not merely one path called the Thumb Road.)

[tjohnson]

Actually, I did mention that earlier -- #31 where I wrote of "celphalic quotients." This was, by the way, the wrong term. The correct term is "encephalization quotient." And my point was and remains that "encephalization quotient" over long spans of time was higher and on an upward trend in cetaceans and proboscideans -- if the fossil record is to be trusted -- for a long time and that the primate leap over them might look like a blip on the radar and not a foregone conclusion. (Encephalization is a bit more trickier than brain size -- it's a brain to body mass ratio.)

You should also be careful in looking for a cortex. That might only be something that only indicates intelligence in mammals. You'd be stuck looking for mammal-like organisms on other worlds. Birds and octopodes have very different brain structures; they don't really have cortexes. And were you to look for them in these animals and to confuse having a cortex with being intelligent, you might expect all birds and all octopodes to be about as smart as garden slugs -- which would fly in the face of observations of some pretty intelligent behavior in both birds and octopodes.

Yeah well you gotta go with what you know. I don't see too many bird scientists here on earth.

[Christopher]

The problem with assuming thumbs is that it assumes hands, and hands assume limbs, and limbs assume a full other development path that includes mammals and reptiles, etc. Counter that with dolphins being considered "relatively smart" compared to the rest of the animal kingdom but vastly different from humans, and I think we find a lot of space for variation in the evolution of cognition.

That's not to say that opposable thumbs aren't a good way to approach the problem. I like the idea. I mean, we'd have to invent a whole new way of playing Nintendo if we didn't have thumbs!

[tjohnson]

The problem with assuming thumbs is that it assumes hands, and hands assume limbs, and limbs assume a full other development path that includes mammals and reptiles, etc. Counter that with dolphins being considered "relatively smart" compared to the rest of the animal kingdom but vastly different from humans, and I think we find a lot of space for variation in the evolution of cognition.

That's not to say that opposable thumbs aren't a good way to approach the problem. I like the idea. I mean, we'd have to invent a whole new way of playing Nintendo if we didn't have thumbs!

But an animal without limbs, like a snake, does not need a complex nervous system to survive, Basically it just needs to recognize food, strike and swallow it. Compare this to living in a cold climate where you have to hunt animals, use their skins as clothing, build shelters, make fires, etc. None of this is possible without not only hands, but fingers and thumbs that allow very fine movements and use of objects. Intelligent aliens would have to manipulate objects and so would need hands and fingers, unless they can do it with telekinesis but we all know thats impossible right??

[dan2100]

Actually, I did mention that earlier -- #31 where I wrote of "celphalic quotients." This was, by the way, the wrong term. The correct term is "encephalization quotient." And my point was and remains that "encephalization quotient" over long spans of time was higher and on an upward trend in cetaceans and proboscideans -- if the fossil record is to be trusted -- for a long time and that the primate leap over them might look like a blip on the radar and not a foregone conclusion. (Encephalization is a bit more trickier than brain size -- it's a brain to body mass ratio.)

You should also be careful in looking for a cortex. That might only be something that only indicates intelligence in mammals. You'd be stuck looking for mammal-like organisms on other worlds. Birds and octopodes have very different brain structures; they don't really have cortexes. And were you to look for them in these animals and to confuse having a cortex with being intelligent, you might expect all birds and all octopodes to be about as smart as garden slugs -- which would fly in the face of observations of some pretty intelligent behavior in both birds and octopodes.

Yeah well you gotta go with what you know.

But you don't know is my point.

I don't see too many bird scientists here on earth.

But how do you know that, off Earth, scientists might not have evolved from a bird-like or octopus-like line?

Edited May 4, 2010 by Dan Ust

[tjohnson]

But how do you know that, off Earth, scientists might not have evolved from a bird-like or octopus-like line?

I think I addressed that in my post to Christopher somewhat. If you are asking is it possible that scientists could evolve from bird-like animals then my answer would be yes, BUT, there wings would have to morph into arms and they would have to evolve fingers to make tools etc. etc.

[Christopher]

But an animal without limbs, like a snake, does not need a complex nervous system to survive, Basically it just needs to recognize food, strike and swallow it. Compare this to living in a cold climate where you have to hunt animals, use their skins as clothing, build shelters, make fires, etc. None of this is possible without not only hands, but fingers and thumbs that allow very fine movements and use of objects. Intelligent aliens would have to manipulate objects and so would need hands and fingers, unless they can do it with telekinesis but we all know thats impossible right??

Well, I think the dolphin example suggests brains can get bigger even with relatively limb-less bodies. I could also imagine a snake beginning to use its body to achieve tasks by wrapping and squeezing things. Now, whether on another planet there are cold climates and it is necessary to hunt animals... that itself implies a system similar to Earth, and you cannot make that assumption. Perhaps just nosing things would be sufficient to release heat from plants that exist in the wild. And then we could even go further and ask whether the use of tools and fine motor skills is the primary contributor to brains, or if it is a socializing/cultural aspect that allows teamwork and carry-over of environmental knowledge. If teamwork, similar to dolphins and other primates, is a focal point for cognitive growth, then brains could evolve in just about anything.

It is a tough pickle. But on other planets, they don't know what a pickle is. The question is, is it still tough for them without the pickle?

[dan2100]

But how do you know that, off Earth, scientists might not have evolved from a bird-like or octopus-like line?

I think I addressed that in my post to Christopher somewhat. If you are asking is it possible that scientists could evolve from bird-like animals then my answer would be yes, BUT, there wings would have to morph into arms and they would have to evolve fingers to make tools etc. etc.

I'm not sure what would be reused were something bird-like to become more of a tool-using animal than currently. As you're probably aware, birds do use tools. Aside from the more stunning recent findings of tool-making and use in crows, many birds already build nests, which involves gathering materials and, often refashioning them to build a complicated structure. This is done, in examples I've seen, mostly using the beak with the claws usually being used merely to hold and transport rather than pick or reshape. Were I to speculate on further refinements of this, I imagine that the wings would NOT "morph into arms." I think the likely path might be more along the lines of the beak evolving further and maybe better coordination with the legs and claws. This might leverage, in some birds, a very flexible kneck (compared with humans, that is).

But this is just my guess. It's not meant so much as a knockdown proof of how evolution of bird-like animals toward technological civilization will actually take place, but more to show that your view seems wanting. In other words, I don't expect ET to have hands and look basically human -- even if they might be covered in feathers.

[tjohnson]

But an animal without limbs, like a snake, does not need a complex nervous system to survive, Basically it just needs to recognize food, strike and swallow it. Compare this to living in a cold climate where you have to hunt animals, use their skins as clothing, build shelters, make fires, etc. None of this is possible without not only hands, but fingers and thumbs that allow very fine movements and use of objects. Intelligent aliens would have to manipulate objects and so would need hands and fingers, unless they can do it with telekinesis but we all know thats impossible right??

Well, I think the dolphin example suggests brains can get bigger even with relatively limb-less bodies. I could also imagine a snake beginning to use its body to achieve tasks by wrapping and squeezing things. Now, whether on another planet there are cold climates and it is necessary to hunt animals... that itself implies a system similar to Earth, and you cannot make that assumption. Perhaps just nosing things would be sufficient to release heat from plants that exist in the wild. And then we could even go further and ask whether the use of tools and fine motor skills is the primary contributor to brains, or if it is a socializing/cultural aspect that allows teamwork and carry-over of environmental knowledge. If teamwork, similar to dolphins and other primates, is a focal point for cognitive growth, then brains could evolve in just about anything.

It is a tough pickle. But on other planets, they don't know what a pickle is. The question is, is it still tough for them without the pickle?

Well why haven't dolphins and primates evolved the specialized brain tissue that we humans have? What have we done that encouraged this to evolve?

[tjohnson]

But how do you know that, off Earth, scientists might not have evolved from a bird-like or octopus-like line?

I think I addressed that in my post to Christopher somewhat. If you are asking is it possible that scientists could evolve from bird-like animals then my answer would be yes, BUT, there wings would have to morph into arms and they would have to evolve fingers to make tools etc. etc.

I'm not sure what would be reused were something bird-like to become more of a tool-using animal than currently. As you're probably aware, birds do use tools. Aside from the more stunning recent findings of tool-making and use in crows, many birds already build nests, which involves gathering materials and, often refashioning them to build a complicated structure. This is done, in examples I've seen, mostly using the beak with the claws usually being used merely to hold and transport rather than pick or reshape. Were I to speculate on further refinements of this, I imagine that the wings would NOT "morph into arms." I think the likely path might be more along the lines of the beak evolving further and maybe better coordination with the legs and claws. This might leverage, in some birds, a very flexible kneck (compared with humans, that is).

But this is just my guess. It's not meant so much as a knockdown proof of how evolution of bird-like animals toward technological civilization will actually take place, but more to show that your view seems wanting. In other words, I don't expect ET to have hands and look basically human -- even if they might be covered in feathers.

I ask you the same thing I asked Christopher - what do you think lead to the evolution of the highly specialized human nervous system?

[dan2100]

But an animal without limbs, like a snake, does not need a complex nervous system to survive, Basically it just needs to recognize food, strike and swallow it. Compare this to living in a cold climate where you have to hunt animals, use their skins as clothing, build shelters, make fires, etc. None of this is possible without not only hands, but fingers and thumbs that allow very fine movements and use of objects. Intelligent aliens would have to manipulate objects and so would need hands and fingers, unless they can do it with telekinesis but we all know thats impossible right??

Well, I think the dolphin example suggests brains can get bigger even with relatively limb-less bodies. I could also imagine a snake beginning to use its body to achieve tasks by wrapping and squeezing things. Now, whether on another planet there are cold climates and it is necessary to hunt animals... that itself implies a system similar to Earth, and you cannot make that assumption. Perhaps just nosing things would be sufficient to release heat from plants that exist in the wild. And then we could even go further and ask whether the use of tools and fine motor skills is the primary contributor to brains, or if it is a socializing/cultural aspect that allows teamwork and carry-over of environmental knowledge. If teamwork, similar to dolphins and other primates, is a focal point for cognitive growth, then brains could evolve in just about anything.

It is a tough pickle. But on other planets, they don't know what a pickle is. The question is, is it still tough for them without the pickle?

I think there's some evidence for social cooperation driving increases in brain complexity and, presumably, intelligence. I don't have a source handy, but I've read about views that living in a complex society means that the animal might be more favored that evolves a means to model other members of the society -- their behavior and the like. Obviously, even more complicated cooperation can come about from this. Weighing somewhat against this is, of course, that many animals, including many primates, live in complex societies, but they're not all walking around with complex brains of the sort we see in humans.

Also, regarding tool use, I think it one has to wonder about tool use in much smaller brained hominins. I believe the first evidence for tool use in homonins is about 2.5 million years ago with the Olduwan toolkit. Hominins from around this time, ergaster and habilis, if my memory's correct, were pretty small-brained. Also, chimps use tools in a way that seems similar to how some early hominins or pre-hominins might have used them. Presumably, tool use in primates is not something new and doesn't require huge brains (or really complicated ones or really high encephalization quotients).

Of course, GS is arguing over very fine control -- and one gets the idea of chimps gathering termites with a blade of grass perhaps being finer limb control than a dog digging in the yard, but not as good as a neurosurgeon (or presumably H. Erectus and Neanderthals). But if we're speculating about the road to intelligent brains and to technological civilization, I think, again, there are many paths to the top of the mountain -- and not all of those paths run the way of having a human-like body plan. Again, I don't see why an elephant-like animal or an octopus-like animal would never ever ever ever ever be able to evolve into something capable of technological civilization and remain very un-human-like in its body structure.