The Man In A Suit - Alien Evolution

[gumboot]

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.

 

[SezMe]

I see no reason why they could not resemble terrestrial octopi, for example.

 

[Mojo]

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?

 

[Mikemcc]

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.

 

[gumboot]

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.

 

[gumboot]

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.

 

[McHrozni]

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

 

[gumboot]

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.

 

[StankApe]

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.

 

[McHrozni]

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.

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

 

[gumboot]

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.

 

[Halfcentaur]

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.

 

[Halfcentaur]

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.

 

[Roboramma]

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

 

[Roboramma]

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)

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

 

[Mojo]

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.

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.

 

[dlorde]

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.

 

[dlorde]

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)

 

[dlorde]

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.

 

[Cayvmann]

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.