What is the precise cause of tool-using sapience?

[Bulldog Psion]

Hi all, here's a thread that I hope will create some interesting brainstorming and speculation, and all, hopefully, in a friendly way. I can't think of how this could link easily into politics, so it should "float" in that sense relative to the rules. As for religion, all I can do is ask people -- please don't bring it in. It will just get the thread locked.

Anyway, I'm wondering about what exactly caused tool-using sapience to arise in our species. I'm using a narrow definition here because I don't want to get into the whole "dolphins are sapient too" thing that could derail my point.

What I'm wondering is what exact setup is needed to prompt evolution into a tool-using sapient with language, complex social organizations, eventual high technology, and at least the potential to eventually create a spacefaring civilization. Call my definition of sapience old-fashioned if you want, :smallwink: but that's what my thoughts are about here.

Anyway, here are my thoughts and some questions, in no particular order.

1. It seems plain to me (pace vegetarians) that our species is a highly adaptable omnivore with a definite but not exclusive taste for meat. We also have the drive for dominance and expansion you'd expect from an apex predator (please note that apex predator doesn't imply a hypercarnivore -- it's quite possible to be an omnivorous apex predator, as humans, and grizzly bears -- who eat only 10% meat, prove).

2. I also think it's likely that "out of the trees" hypothesis explains our bipedalism and our manipulative hands, at least to some extent. I'll tie this in with another idea further down the line.

3. There is speculation that bipedalism drives sapience, as it frees the hands for use. However, this begs another question -- why, then, is there no evidence of tool-using sapience in numerous other bipeds? Particularly, I'm looking at dinosaurs -- they had relatively clever bipeds with binocular vision and relatively dexterous hands for a long time. Tens of millions of years. Yet we have no sign of tool-using, city-building sapience among them.

4. Is it possible that dinosaurs evolved a tool-using sapient and it is simply too long ago for the traces to be preserved? I find this difficult to believe; stone buildings, stone artifacts, and even certain metal tools should survive in some form if fossilized bones survive. But I may be wrong.

5. It seems to me that bipedalism -- freeing the hands for use -- and sapience are linked, but not inevitably. Is it plausible that a complex set of circumstances led to tool-using sapience in humans, basically related to climate? Here's my current, probably idiotic, theory --


Humans were largish, slightly omnivorous tree-dwelling apes at some point, evolving a fairly upright body plan.
These pre-humans also developed grasping hands for climbing, and likely binocular vision for depth perception in the trees.
Climate change, hypothetically, caused the forest to shrink and grasslands to grow.
These large, relatively clever apes were deprived of the habitat needed to support their large body size (fruits, for example, became scarcer over time)
They were forced onto the ground, but the grasslands are relatively poor in non-protein foods for a great ape.
The proto-humans had adaptations to survive, however. Large brains got larger, social organization increased, and grasping hands were used to make weapons.
Weapons were necessary because of trophic demands too high to be supplied by eating grass or termites in the absence of forest with rich fruit resources.
Humans are too slow and lack the raw physical fighting power to take down prey efficiently. Therefore, selective pressure favored those best able to hunt with tools -- large brains, tool use with hands, and the ability to plan together to make ambushes, etc. to compensate for lack of speed.
Being placed in this situation also favored those groups able to defend good hunting grounds against other humans -- with tactical advantage lying with those with able to think up better plans (pressure for bigger brains), make better tools (improved manual dexterity), and work together well (improved, detailed communication).
The results were a tool-using sapient.


This theory would lead to four main conclusions, IMO:

A. Why we got sapience at all. We happened to have a suite of abilities that were well adapted to it, by chance -- upright stance freeing hands for tool use, largish brain ready to expand, dexterous hands -- and were forced to use them for survival by climate change that eliminated a previous environment (forest) and placed our ancestors into a situation where they could only get enough food by hunting (grassland).

B. This would explain why bipedal dinosaurs with manipulating hands didn't develop tool-using sapience. They may well have had the preconditions for it -- grasping hands, binocular vision, maybe even complex social organization (packs) with some complex communication already going on. But if they were already well adapted to their environment, and weren't suddenly thrown into a situation where they were required to develop tool-use and language or die, there was no selective pressure to develop those traits beyond the level they were already at.

C. If this is so, it would indicate that tool-using sapience requires a pretty special set of circumstances to arise. The preconditions may be fairly common -- manipulating appendages, largish brain, etc. But a disaster big enough to require evolution into a "tactical omnivore," but not so big as to cause outright extinction, is needed to give the final shove onto the road towards tool-use, language use, and technology. Most species with the necessary adaptations either continue for a long, long time without needing to take that step, or are eradicated by a disaster too big to adapt to. Humans just happened to be an animal with the necessary features exposed to just enough pressure to make the evolutionary transition.

D. This will probably be the most controversial idea, but I assume that continuing evolution along the "tool-using, language-using path" was driven primarily by competition against other humans, the most effective competitors for resources against something as cunning and versatile as an emergent tool-using sapient.

I'm also assuming it would be harder for an obligate herbivore or a hypercarnivore to make this jump because their more specialized dietary needs would tend towards driving them extinct if conditions shifted, rather than powering evolution. Omnivores would be best positioned for this, and I think everything indicates that we are indeed adapted to be highly versatile omnivores.

Thoughts? Ideas? Observations? Am I being plausible, or am I full of hot air? :smallbiggrin: Or fuller than usual, I should say.

[The Grue]

...This would explain why bipedal dinosaurs with manipulating hands didn't develop tool-using sapience. They may well have had the preconditions for it -- grasping hands, binocular vision, maybe even complex social organization (packs) with some complex communication already going on. But if they were already well adapted to their environment, and weren't suddenly thrown into a situation where they were required to develop tool-use and language or die, there was no selective pressure to develop those traits beyond the level they were already at.


Just thought I'd mention that corvids (particularly crows) hit a few of your requirements for sapience as well; tool use and construction, complex social hierarchies, and (rudimentary) language. Since it's commonly accepted that the modern avian is descended from theropod dinosaurs, I would argue that there may in fact be a species of tool-using, proto-sapient dinosaur - notably, one whose forelimbs are not capable of fine manipulation.

[shawnhcorey]

Chimpanzees use tools. Are they sapient?

From Ape to Human in a Nutshell

From 18 million years ago to about 6 million, Africa was covered entirely in jungle. This gave rise to many apes species. So many species that it is nicknamed the Planet of the Apes.

About 6 million years ago, Africa dried up and the jungles were replaced with open woodland. Our ancestors left the trees and spent a large portion of their time on the ground. This was when we evolved walking upright. The best reason why was giving by Dr. Gen Suwa in one of his CARTA talks: he asked the specialists in chimpanzees and bonobos and he said that apes spend about half their time on the ground walking upright. It seems our ancestors did it for the simplest reason of all: they wanted to. And their brain size was similar to that of the apes.

About 2 million years ago, the climate of Africa changed again and it went from open woodland to savanna. This was the time when the first Homo species appeared. It was when our ancestors developed stone tools and started hunter-gatherer societies.


Why did our ancestors start to use tools? Nobody knows for sure but it is almost certain that before they began tying sharpened rocks to the end of a stick and poking large animals with them, they were poke sticks at smaller animals. And just to add confusing, here is a video clip from Nova and National Geographic on chimpanzees using spears (http://video.nationalgeographic.com/video/chimp_spear).

[Gnome Alone]

There seems to be a general trend on this planet towards greater complexity and awareness. I don't think there's anything special about our use of tools; other species use then somewhat, and many species, like dolphins, do have a degree of sentience, and it seems likely that many of them could eventually become as self-aware as we are.

I mean, your specific speculations as to the origins of it are intriguing, but what I'm saying is I don't think it's all that awesomely (using that word in its actual sense here, for once) significant as a question cuz we ain't all that special. IMHO, etc.

[NichG]

I guess I'd take another tack and say, why would we expect sapience to require such precise and specific conditions to emerge? Its not like there aren't examples of things we would consider to be pre-sapient making use of contrived environmental structures - tool use isn't structurally that much different than, say, birds evolving the behavior to drop things onto rocks from high up in order to crack them open. Its not identical of course - tool use can allow adaptations in tool design and things like that, where the bird is unlikely to be able to change how the rocks are shaped to make them work better, but it seems like the precursors were well in-place. Even things like dam-building behavior or nest-building behavior are, in a sense, 'tool-use' of a very primitive form.

To my mind, there are two features that basically need to be addressed. One is, can one understand what 'tool use' specifically means in terms of novel ways of processing the relationship between behavior, outcome, environment, etc - as opposed to 'non-tool use'. The other is, given a (quantitative) definition of the previous, can one explain the modern distribution of 'tool use' across various branches of life? For example, it may be that there's a critical threshold in the amount of tool use at which point higher sapience develops very quickly, so you would only expect to see one advanced tool using species because the average time between the development of the first 'critically advanced tool user' and the second one is much longer than, say, the time to go from a 'critically advanced tool user' to a spacefaring civilization.

Timeline-wise, the oldest tools we've found seem to be in the millions-of-years range. That does suggest that it actually takes a significant timespan (in terms of evolutionary timescales) to go from shaping bits of stone to being sophisticated enough to ask this question. So then the question is, what's the characteristic timescale of the fluctuation that causes the development of environment-shaping behaviors of this sort? My personal guess is that if you cast a wide enough net, the structural motifs of 'tool use' in the sense of taking and manipulating a bit of the environment to be more useful to you are really really old, and a lot more common than just homo sapiens.

That said, my own wild guess for the cognitive features necessary to start a runaway process is the development of symbolic/representational cognition. There seem to be different types of learning - a sort of Pavlovian stimulus-response is one type and its pretty common; the other however is something where the features of the world can be internally represented in a sort of modular fashion (symbols representing bits of the world) and furthermore can be exchanged or re-arranged to 'figure out' situations which the creature has never before directly encountered during their lifetime and for which they don't have an instinctual response.

In other words, its the cognitive feature that allows 'information' to be retained and transmitted within a species on a scale longer than what each individual member of the species has personally encountered/learned. This could be through language, but could also be through e.g. 'teaching' and mimicry. That kind of thing means that now you have a new evolutionary process operating on a timescale much shorter than genetic evolution, which is exactly the sort of thing you'd expect to create a kind of gap (because everything above threshold suddenly develops much faster, and the information-exchange character of it means that the population pulls itself along so you don't end up leaving behind straggler species for very long).

[Bulldog Psion]

There seems to be a general trend on this planet towards greater complexity and awareness. I don't think there's anything special about our use of tools; other species use then somewhat, and many species, like dolphins, do have a degree of sentience, and it seems likely that many of them could eventually become as self-aware as we are.

I mean, your specific speculations as to the origins of it are intriguing, but what I'm saying is I don't think it's all that awesomely (using that word in its actual sense here, for once) significant as a question cuz we ain't all that special. IMHO, etc

Well, I'm mostly interested in why that step is taken, and why animals that have some of the preconditions don't take the step.

Some theories I've seen postulate that bipedalism and the freeing of the hands is enough to drive further evolution towards tool-using sapience. To which I answer, then why not the bipedal dinosaurs, which were physically set up for it and had literal aeons to evolve?

I don't doubt that dolphins may already be as self-aware as we are. But they're not using tools, building cities, surfing the Internet, studying evolution, or having the (remote) potential to colonize other planets. There's some explanation for why we are what we are, and nothing else has achieved similar results. A chimp using a twig to get out termites has the potential, but that potential hasn't expanded into a remote fraction of what we see in H. sapiens sapiens. There must be a reason, and this is my attempt to postulate it.

Nothing special about our use of tools? Well, I'm going to have respectfully disagree with you there, though of course I'm open to being persuaded I'm wrong. But at the moment, I fail to see perfect equality of function and power between a broken grass stem or a pebble, and a supersonic jet, the Internet, the moon landings, or an electric grid. It's like positing there's no functional difference between a single drop of water and the ocean. I mean sure, anything can be dismissed that way -- "eh, a galaxy is no big deal, after all kitchen matches exist" -- but it seems like it just deflates the purpose of discussing anything if even the largest differences are written off as trivial at the outset.

[The Grue]

I don't doubt that dolphins may already be as self-aware as we are. But they're not using tools, building cities, surfing the Internet, studying evolution, or having the (remote) potential to colonize other planets. There's some explanation for why we are what we are, and nothing else has achieved similar results. A chimp using a twig to get out termites has the potential, but that potential hasn't expanded into a remote fraction of what we see in H. sapiens sapiens. There must be a reason, and this is my attempt to postulate it.

I'm curious why you can extrapolate humanity's ability to colonize other planets, but you're unwilling to take a similar speculative leap for other animals - like, say, the tool-using great apes or, as I mentioned earlier, corvids.

[NichG]

Nothing special about our use of tools? Well, I'm going to have respectfully disagree with you there, though of course I'm open to being persuaded I'm wrong. But at the moment, I fail to see perfect equality of function and power between a broken grass stem or a pebble, and a supersonic jet, the Internet, the moon landings, or an electric grid. It's like positing there's no functional difference between a single drop of water and the ocean. I mean sure, anything can be dismissed that way -- "eh, a galaxy is no big deal, after all kitchen matches exist" -- but it seems like it just deflates the purpose of discussing anything if even the largest differences are written off as trivial at the outset.

Well, I'd say a ribosome is more functional/powerful than a supersonic jet, for example. The difference between 'oh, there are ribosomes' and 'oh, we build supersonic jets' is the layer of understanding in 'build'. Biology doesn't learn from inventing ribosomes, except for having ribosomes now, but sapient development not only gets the product but also learns a set of generalized principles that apply towards future projects. It makes the processes of development go at different rates, which is why it has only taken us a million years to start catching up on what took a billion years to figure out via genetic algorithms.

[Gnome Alone]

I'm just saying we got there first, but I (if I could, y'know, live a few million more years) wouldn't be surprised when dolphins, chimpanzees, elephants, corvids, et cetera, catch up to us.

In self-awareness and the capacity for higher abstract thought, one manifestation of which is tool use. Not necessarily that there'll be the exact same kind of development but something with a family similarity? I'd bet on it.

The differences are quantitative, not qualitative; that's what I meant by "nothing special."

[Eldan]

First of all:


Humans are too slow and lack the raw physical fighting power to take down prey efficiently. Therefore, selective pressure favored those best able to hunt with tools -- large brains, tool use with hands, and the ability to plan together to make ambushes, etc. to compensate for lack of speed.

Meeeep. Humans can hunt unarmed on foot and very, very efficiently. Even a single human. Especially in a savannah climate, there is no animal that can match the endurance of a trained human hunter. There are still societies out there where single hunters kill antilopes by just walking after them until it drops dead from exhaustion.

There is an interesting theory that whta drove sapience in humans were other humans. Apes live in small groups, by nature and there is always competition. Between group members (for food, mates, social position) and between groups (for territory, access to resources, etc.). Chimpanzees, effectively, go to war against other tribes. And in such an environment, intelligence may help a lot, in ways it would not necessarily be required for hunting.

Another factor that ties into group is culture. Elders teaching things to the younger. Apes, again, do it to a certain degree.

[ace rooster]

I work with horses, and have in the past worked with sheep, cattle and obviously dogs. The only thought process that I use that I have not seen an animal use is the capacity for abstract language with syntax.
Herd animals obviously comunicate with each other readily, but are limited to showing each other the solution to a problem, and so cannot help each other when difficulties are not visually apparant. For example a critical flick of the wrist to get a bug out of a tree that is very easy to miss, and difficult to get just by looking. If someone can explain it then it is much easier. I believe this is why primitive language was selected for.
The other point is that language effectively gives you a map for your thoughts and experiences, allowing you to recall a specific piece of information without being in the correct context. When I think "kitchen" I can picture a particular place, without having to go through a maze of associations to trigger that memory. Using syntax we can connect things that have no context relation, just by putting the words together. For example, a hippo sitting painting a house. This would never happen, but from the language we can picture it instantly. This is very important because it allows us to build modular tools, and very neatly black box the function of each module.

I would think a basic syntax would be selected for to coordinate hunting or raiding tactics, but complex tool use would be required for the development of complex language. The basic syntax would permit complex tools that would make a more advanced language useful. Everything spirals from there. Humans were just the perfect storm of conditions to trigger this spiral.

The other possibility is that it is just a byproduct of our ability to track prey without scent, which is our main method of hunting (chase it till it dies, no joke. The guy's spear is ceremonial).

[shawnhcorey]

Apes live in small groups, by nature and there is always competition. Between group members (for food, mates, social position) and between groups (for territory, access to resources, etc.). Chimpanzees, effectively, go to war against other tribes. And in such an environment, intelligence may help a lot, in ways it would not necessarily be required for hunting.

Chimpanzees are aggressive and will not share food. Bonobos are non-aggressive and will share food with complete strangers. So which were our ancestors like? According to Dr, Gen Suwa, a paleoanthropologist who specialized in the analysis of cranial and dental remains from ancient hominds, our ancestors canine teeth were small, like the bonobos, and not large, like the chimpanzees. His conclusion is that our ancestors were non-aggressive.

Brain size, on the other hand, are more significant when determining how our ancestor thought. Brain size was fairly constant from 6 million years ago until about 2 millions years ago. After 2 millions years, brain size increased. For most researchers, this is thought to be because Africa climate varied from wet to dry and back. This would force each generation to find new food sources. Larger brains were needed to find new food sources and process them.

[Kato]

First off: I'm sure if you can find a satisfying answer to that, you'll get a Nobel prize :smallwink:

And now some random notes:


4. Is it possible that dinosaurs evolved a tool-using sapient and it is simply too long ago for the traces to be preserved? I find this difficult to believe; stone buildings, stone artifacts, and even certain metal tools should survive in some form if fossilized bones survive. But I may be wrong.
Without much knowledge in archeology... That's something I also wonder at times. Without spawning any crazy theories, I don't think it is unlikely any remnant of a dinosaur civilization could be destroyed in the last 65 mio years. It's a lot of time and from a more or less random guessing point of view: I think even if you try to set a mark that last that long there's a good chance it won't be recognizable after so long... And also we do a lot of digging for old stuff to learn about the past, it may just be we've been digging in the wrong places?
Of course, iirc I don't think we've ever found a fossil of a dinosaur with hands which are suited for the use of tools which is kind of a handicapped if you... well, want to use tools. Which obviously raises te question, as you say, why they never got aroudnd to it in so long a time.

But it seems very unlikely dinosaurs were ever faced with any (drastic) environmental changes which would have triggered a necessary evolutionary spurt or anything. There are constantly changes in the world, from what I recall, and if those were what bipedal, predatory, large-ish dinosaurs needed they should have gotten them, I'd wager.
My guess is... we got lucky :smalltongue:


I mean, your specific speculations as to the origins of it are intriguing, but what I'm saying is I don't think it's all that awesomely (using that word in its actual sense here, for once) significant as a question cuz we ain't all that special. IMHO, etc.
I think while it is pretty hard to get a good grasp of the sentience of an animal, we humans still happen to be way ahead of most, if not all... Why is a very difficult question, and I'm surely not saying they couldn't catch up, but right now without getting into philosophical things, we are the second dominating species in the world, which sets us quite a bit apart from others. (Right after cats, obviously :smalltongue:)


[...] His conclusion is that our ancestors were non-aggressive.

Again, without too much background knowledge, it seems not entirely conclusive. Maybe it's just me being cynical, but humans evolving from a non-aggressive ancestor seems unlikely to me :smallbiggrin: Obviously, teeth do say something about the owner, but saying our ancestors were more peaceful because they gad smaller teeth just seems like indicative evidence... you can bite pretty hard with small teeth as well.

[Frozen_Feet]

Tool use isn't structurally that much different than, say, birds evolving the behavior to drop things onto rocks from high up in order to crack them open. Its not identical of course...

Actually, it is identical, in case of corvids and several other species of birds. The behaviour is not genetic, it is learned and culturally transmitted in a flock. For even clearer example of corvid intelligence, Japanese crows have learned to crack nuts open by placing them before cars.... while traffic lights are red, and the cars are still.

I think we can safely conclude this behaviour can't be genetic, as traffic lights are a contemporary invention and there was nothing like them in existence when Japanese crows evolved to be like they are now.

Same goes for dolphins. Not only do they use tools they themselves make from materials found in the seas, they have also shown capacity to learn and benefit from human-made inventions, as shown in dolphins pursuing fishes towards nets cast by fishers.

If tool-use and self-awareness are taken as evidence for sapience, then several species of dolphins, corvids, apes and monkeys qualify. Some of these species appear to have their own languages and cultures too, and can be taught human forms of communication. Still not quite on the level of humans, but not so far as many people would like to pretend either.

[Eldan]

Chimpanzees are aggressive and will not share food. Bonobos are non-aggressive and will share food with complete strangers. So which were our ancestors like? According to Dr, Gen Suwa, a paleoanthropologist who specialized in the analysis of cranial and dental remains from ancient hominds, our ancestors canine teeth were small, like the bonobos, and not large, like the chimpanzees. His conclusion is that our ancestors were non-aggressive.

Brain size, on the other hand, are more significant when determining how our ancestor thought. Brain size was fairly constant from 6 million years ago until about 2 millions years ago. After 2 millions years, brain size increased. For most researchers, this is thought to be because Africa climate varied from wet to dry and back. This would force each generation to find new food sources. Larger brains were needed to find new food sources and process them.

That may be a driver for our brains, but even primates as a whole are quite intelligent. More so hominids. and there, competition theories sound like reasonable explanations.

Also, by competition, I don't necessarily mean aggression. Even Bonobos need some system to distribute food and social status.


But it seems very unlikely dinosaurs were ever faced with any (drastic) environmental changes which would have triggered a necessary evolutionary spurt or anything. There are constantly changes in the world, from what I recall, and if those were what bipedal, predatory, large-ish dinosaurs needed they should have gotten them, I'd wager.

Again, birds. Amazing radiation, giant diversity. The dinosaurs never died out.

[shawnhcorey]

Also, by competition, I don't necessarily mean aggression. Even Bonobos need some system to distribute food and social status.

Yup, they share their food equally.

Also, I don't know where this idea that tool-use is an indication on sapience. A better indicator would be the mirror test (https://en.wikipedia.org/wiki/Mirror_test). But if you want to insist on tool use, there a quite a number of animals that create and use tools (https://en.wikipedia.org/wiki/Tool_use_by_animals).

[Eldan]

The mirror test is a sense of self, sure. But personally, I find problem solving tests a lot more interesting. Corvids, man. That's where it's at. Intelligent flying stealth dinosaurs.

[NichG]

Generally we use a loaded term like 'sapience' (or 'life' for that matter) when we feel like there's something missing in our understanding but have a (possibly misplaced) confidence that when we see examples we can sort things cleanly into two categories. So something like 'tool use' or 'language' or even 'sense of self' are much sharper terms and more useful to discuss than debating which of those qualify something for 'sapience'.

An even more useful thing may be to pin down what exactly we're actually trying to understand here. Let me take a rough shot at it:

If I look around me in my environment, I can see objects that have been assembled that have similar or complexity to things developed through direct biological evolution, but which use very un-biological design processes and motifs. These un-biological motifs can be quantified in terms of things like the degree of modularity and interchangeability between components, degree of 'recruitment' (using an existing part of the design for a secondary or tertiary purpose), etc. So in some quantifiable way, I can identify that there are at least two distinguishable processes of 'complex structure generation' going on around me.

Furthermore, if I look at the source of these complex structures, its just humans. The next most complex thing built by creatures on Earth is much much simpler, so there's a large complexity gap that suggests that the explanation may be qualitative and not just a matter of degree.

My attempt at a more precise question then is 'what are the key features that are responsible for the emergence of this new mechanism and the corresponding complexity gap?'.

So the data that is on the table so far in this thread is:

- Self-awareness (mirror test) is not unique to humans
- Problem solving is not unique to humans (crows, etc)
- Tool use is not unique to humans (crows, etc)
- Communication/exchange of learned behaviors is not unique to humans
- Societal structures are not unique to humans, nor are aggression/cooperation pressures
- Abstraction/symbolic information transfer may be unique to humans (crow example can be taught via mimicry, painting hippo example still doesn't have a counter-example outside of homo sapiens)
- Humans are the only species we know of in which the generation of secondary 'assembled' objects has even started to approach the complexity of the underlying biological components.

That about sum it up?

[Eldan]

Acutally, chimpanzees seem to be able to understand quite a high degree of abstraction. A group of them was successfully thought the use of currency. And then concepts of inflation.

[NichG]

'Using' versus 'understanding' is often a tricky distinction in this sort of thing though. For example, biofilms use certain molecules to do surveys of population levels of different bacteria within the film and then based on those molecules, the film as a whole can undergo different dynamics (quorum sensing) - but it'd be pretty hard to argue that biofilms 'understand' what they're doing in this case.

The Japanese crows using something that has only entered their environment within the last century in order to solve a problem seems to be a pretty good case for 'understanding' there, since that timescale is a little short for genetics to discover and encode that particular behavior.

For the chimp study, the various links I can find suggest that the currency system was effectively taught to them by the researchers. So does that make it an intermediate case - unable to innovate abstractions, but capable of understanding abstractions if introduced externally?

[erikun]

First, I don't see tool use as the end-all and be-all of humanity. That strikes me as misguided thinking from back when people were first trying to definte the animal/human distinction. There are a lot of things that make humans different from other animals, but tool use because the go-to choice because it was the easiest to observe or test for. However, just because something uses tools does not mean it is more likely, or has a greater chance, at possessing other human attributes. I mean, there are insects that use tools. (http://en.wikipedia.org/wiki/Tool_use_by_animals#In_insects) I highly doubt that anyone is going to claim ants or wasps are the closest creature to human intelligence, though.

Tool use is a good impromptu intelligence test for measuring the creativity/memory/reasoning of a creature (or genetic tendencies, as the ants likely are) but I don't find them to be more than that.

Also, do not discount random variables. It could very well be that the factors for tool use and the factors for sapience were simply at the same place for proto-humans. Just because humans possess both does not mean that one needs to have been caused by another (any more than hairless bodies would be a cause of tool use).



As for dinosaurs, it has been a very long time and it is very hard to find evidence of any sort of civilization from that long ago. I mean, what are the oldest forms of human civilization known? Most of them are either existing cities or structures (make of rock) or paintings/bones in natural caves, neither of which would survive being under several hundred feet of rock. Arrowheads are easy to pick out when found in dirt, and probably impossible to identify from surrounding identical rock.

The biggest issue with finding proof would be to find remains, though, and that will likely end up impossible. Most fossils were preserved in some way, and unless we locate a dino-Pompeii, we are unlikely to find that kind of proof. You do not put a city in the middle of a bog or tar pit for obvious reasons. We can say with relative certainty that dinosaurs did not build steel skyscrapers, nor nuclear power plants, nor wiped out most other living creatures and burnt a bunch of fossil fuels, but I don't see any way of confirming if they had stone arrowheads and hunted that way.

Then again, I find it unlikely. The natural weapons of a dinosaur would make such weapons probably unnecessary.



As for sapience itself, I'm more likely to think that a social group would have a greater impact on it than tool use. A social group pressures creatures to work together and communicate, and as such, groups that work together better are more successful. The ability to communicate improves this social group connection, as does the ability to pass along knowledge. I'd find it more likely that language use, especially complex language use, would encourage the development of sapience moreso than other factors.

This doesn't mean that sapience and tool use are completely independent. Getting a bigger brain to use language better would allow a creature to use tools better as well, so they are likely complementary. However, that doesn't mean one is dependent on the other.

Human omnivorism probably helped this as well, for several different reasons. First of all, I find it more likely that intelligence would develop in a creature with weaker phycial traits, or at least less capability of being successful in its environment. An apex predator may have plenty of energy and food to develop a big brain, but little reason for doing so. It's already an apex predator, and has little reason to change. A scavenger/omnivore, though, is going to get a lot more use out of greater intelligence, being more capable of finding resources and surviving. Take a look at a lot of the apparent intelligent non-human animals, and you don't find many high-level carnivores in them. Crows, rats, and octopuses are all relatively weak and vulnerable to predators, but it's their mental capabilities that allow them to survive.

Omnivorism probably helped humanity's survival through a large population, more than anything else. A carnivore is going to be limited by the amount of prey in the area, but an omnivore is not. I've heard that early human hunter-gatherer societies got 60% of their food and nutritious from the gatherers, which is pretty telling of their survival. Human's ability to drink milk also included a population boom, thanks to the new food source. The larger population not only helps survival, but also helps with the evolution and improvement in an animal - more population means more chance to change, and thus a faster change in the population. If we're talking about mental improvement and a tendency towards sapience, then a population that can take advantage of many food sources will be much more likely to achieve it than a population that is limited to only one food source.

[shawnhcorey]

The oldest human civilization? that would be the ruins in the Indus valley in Pakistan, about 12,000 to 10,000 years ago. It was the first place where irrigation agriculture was practised. Before that, our ancestors were hunter-gatherer with some gardening.

The biggest difference between humans and animals is not that we do something that an animal can't but we do so much more. An adult chimpanzee will take years to learn how to fish for termites but a human can do it in minutes. Our intelligence to so far beyond them, it might as well be magic.

[Rawhide]

What is the precise cause of tool-using sapience?

So disappointed that no one has answered with "black monolith".

[Kato]

So disappointed that no one has answered with "black monolith".
Heh, or more recently:clothing.

[NichG]

I wonder if we're missing a sort of 'critical mass' phenomenon here. Lets say you're considering some feature like 'tool use' or the ability to abstract. Now, rather than saying either 'yes this species has this' or 'no this species doesn't have it', imagine if you're in a situation where, say, 10% of the species is born with the right combination of factors to understand abstractions or use language or something like that. Especially if we're talking something where a large portion of the benefit comes from interactions (like language), having 10% of the species smart enough to use language and the rest being unable to doesn't confer that much gain, but at 20% maybe thats enough for the language users to find each-other and form some sort of stratified society. Or at 30% or whatever.

So if we're talking things where a good chunk of their advantage is synergistic, that might be enough that whatever the particular feature is that is needed for a runaway process of advancement won't be completely unique - you wouldn't be able to find what it is just by asking 'what things do only humans have?'. Instead, you'd expect it to be sitting around at low levels but maybe present in many different species, just never above some certain population fraction which'd be the whatever the critical threshold is for the runaway process.

What you might expect to see though is fluctuations that are characteristic of the nearby instability - micro-civilizations that didn't get very far before they fell apart. This might show up as a higher degree of variability between observations of different tribes or social groups of the same species - basically, if all wolf packs are basically the same but some groups of chimps use the currency idea and others don't, or things like that, it could indicate distance from the transition.

[Soras Teva Gee]

Meeeep. Humans can hunt unarmed on foot and very, very efficiently. Even a single human. Especially in a savannah climate, there is no animal that can match the endurance of a trained human hunter. There are still societies out there where single hunters kill antilopes by just walking after them until it drops dead from exhaustion.

Yeah people need to stop assuming humans are either inferior or average in the physical realm. We're actually the more like the freaking Terminator or Energizer Bunny because we do not ever stop.

[Eldan]

People also forget that the abilty to throw things accurately over a distance is a damn superpower.

[Rawhide]

Unfortunately, the following image does contain multiple different swearwords. So, don't open it if you'd rather not see them, and remember that they cannot be repeated or used here.

>Relevant link.< (http://i.imgur.com/hINj1xf.png)

[Solse]

Basically, humans are pretty damn awesome. There's a reason we're the dominant species on Earth.

[The Grue]

Basically, humans are pretty damn awesome. There's a reason we're the dominant species on Earth.

Are we? One could argue that cockroaches or tardigrades are the dominant species, we're just the most visible.

[Mando Knight]

Are we? One could argue that cockroaches or tardigrades are the dominant species, we're just the most visible.

Ubiquity isn't dominance. Cockroaches and tardigrades have nowhere near the effect on the world that humanity does.

[The Grue]

Ubiquity isn't dominance. Cockroaches and tardigrades have nowhere near the effect on the world that humanity does.

And yet we've only just arrived. Tardigrades have been around, more or less unchanged, for five hundred million years. How arrogant of us to assume we're the most important, most impressive, most dominant thing to arise on this world when we're barely a blip on the geological timescale.

Sure it seems that way to us - but how objective is our own view of ourselves in the absence of any contrary perspective?

[NichG]

Dominance isn't a very meaningful thing between niches. We don't really compete with bacteria for example (infectious disease is a tiny fraction of bacterial biomass).

As far as the versatility of resources we consume though, we're ahead of most (all?) other multicellulars

[The Grue]

My point is that if our definition of "dominance" starts with the assumption that Homo sapiens sapiens is the dominant species, of course our definition is going to support that assumption. It's not something we can really look at objectively.

"Ubiquity is not dominance" - okay, why not? "Versatility of resources consumed is the benchmark for dominance" - okay, why that and not something else? If the only reason for these is because otherwise some other species would be labelled "dominant", isn't that circular reasoning?

[NichG]

My point is that if our definition of "dominance" starts with the assumption that Homo sapiens sapiens is the dominant species, of course our definition is going to support that assumption. It's not something we can really look at objectively.

"Ubiquity is not dominance" - okay, why not? "Versatility of resources consumed is the benchmark for dominance" - okay, why that and not something else? If the only reason for these is because otherwise some other species would be labelled "dominant", isn't that circular reasoning?

I'm not saying that versatility of resources consumed is the benchmark for dominance, I'm saying that its a distinctive feature. As I said, 'dominance' is ill-defined between niches because there isn't actually any competition going on. What you can define however is the degree to which different things modify the environment, adapt different resources, etc - these are measures of influence and complexity and may serve to highlight the characteristics that explain the phenomena we're interested in (namely, what we tend to call 'sapience' or 'intelligence').

'Are we better than bacteria?' is a meaningless question as phrased, and it causes the problem that the answers become more about pride versus humility rather than anything scientifically relevant. Down that particular rabbit hole, you have the problem that it becomes more about the questioner and respondent than the things the question is supposedly trying to investigate - namely that it focuses on whether or not we support humility as a virtue or pride in our own species and things like that. Which makes it easy to get distracted away from talking about the scientific content

'What qualitative differences exist between how we interact with the world and how bacteria interact with the world?' is a better question, though. Or more generally 'what are the different modalities of life and how do they differ?'. For example, individual types of bacteria exist which use pretty much any energy source we know of - some photosynthesize, some break down this or that food source, some use mechanical energy, and there's even an extinct line that was found to have used radioactive isotope decay - but no single bacterium uses all of thses. Multi-cellulars as a class of organism also have a similarly wide variety of inputs.

Humans as a single species, via the prosthetic of technology, process and make use of as wide a variety of things as an entire deep branch of the phylogenetic tree. That seems to be a notable feature, whatever you want to say about 'dominance'. Furthermore, its a feature directly tied to our technology - if you don't count our technology as part of us, then we can't make use of that many more distinct resources than other multi-cellulars. Now, that brings up a question - what about other symbiotic relationships. An individual bacterium might fix sulfur or photosynthesize or eat radioactive decay or whatever, but can you find biofilms that do all of these things, or what if you take entire ecological sub-systems to be the 'individual' of the theory and treat all lower trophic levels as 'technology' for the highest trophic level? That becomes something that needs to be carefully teased out - I don't have a simple answer for it.

So yeah, I would say 'humans do things which are anomalous compared to other species' is a very solid statement. The tricky thing is to tease out exactly what they are, what the boundaries are, and what is actually relevant to the phenomenon to be explained (namely, run-away technological development/sapience/etc)

[Miklus]

I recently read a book about this and I just want too add something I found surprising.

Humans started banging rocks together about 2.5 million years ago (Oldowan culture). Then it took one million years before someone figured out a slightly more efficient way of banging those rocks together (Acheuléen culture). Only in the last 50.000 years or so do we see creativity like wall paintings, jewlery, figurines and so on. Learning how to make tools did not exactly happen overnight.

Both the Oldowan and Acheuléen culture made the so-caled hand-axes, witch consists of a pointy rock held in the hand. Tools don't get much more primitive than that. The difference between them is that in the latter, the rock is sharpend on both sides. It is symetrical. That took one million years to come up with! That's 1,000,000 years of banging rocks together before someone thought "maybe I should try sharpening the other side too...?".

I think toolmaking is a lot harder than we think. Crows, breavers and even chimpanzees are nowhere near human levels.

[Frozen_Feet]

If we want to argue about the dominant species, then both in terms of biomass and effect on environment, it's the Formicidae family, ie. ants that win both contests.

According to recent estimations, various ants make up around 50% of animal biomass and provenly can build colonies that span continents and have environmental effects on national levels.

[shawnhcorey]

Both the Oldowan and Acheuléen culture made the so-caled hand-axes, witch consists of a pointy rock held in the hand. Tools don't get much more primitive than that.

Actually, there is one tool more primitive but since it's made from wood, there are no remains: the digging stick.

[NichG]

If we want to argue about the dominant species, then both in terms of biomass and effect on environment, it's the Formicidae family, ie. ants that win both contests.

According to recent estimations, various ants make up around 50% of animal biomass and provenly can build colonies that span continents and have environmental effects on national levels.

Curiously, Wikipedia's numbers suggest that the total human biomass exceeded the upper bound estimates for ants somewhere between 2005 and 2012, when we went 287 million tons to 350 million tons (ants are at 30-300 million tons on that table). Termites, however, are at 445 million tons. Meanwhile, bacteria weigh in at 350000-550000 million tons. They're basically tied with 'everything that isn't bacteria' for biomass (of which most is plants).

As far as effect on environment, that sounds like ants and humans are probably roughly tied, since, well, nations also have environmental effects on national levels... But we're both behind 'transforming the entire planetary atmosphere into something highly toxic' - e.g. the oxygen event.

[Eldan]

Plus, ants are a lot of different species, not one.

[Ravens_cry]

Actually, there is one tool more primitive but since it's made from wood, there are no remains: the digging stick.
Sometimes scientists get very lucky and find really ancient wooden artefacts (http://en.wikipedia.org/wiki/Sch%C3%B6ningen_Spears).

[Kato]

While I'll admit the whole "dominant species" thing is kind of hard to make out, but e.g. the fact we can pretty effectively genocide most other species if we want to (though, total ant genocide would probably be hard to achieve) is a factor. Or, we could really kill 90% of earth's species if we wanted to, even if it took us with them. That would be pretty hard for most others. (And yes, the fact that we even can communicate about doing this - and decide against it - is part of our dominance)

I'll admit it's a biased opinion but in my book we pretty much rule a pretty large chunk of this rock and do with it as we please.

[NichG]

While I'll admit the whole "dominant species" thing is kind of hard to make out, but e.g. the fact we can pretty effectively genocide most other species if we want to (though, total ant genocide would probably be hard to achieve) is a factor. Or, we could really kill 90% of earth's species if we wanted to, even if it took us with them. That would be pretty hard for most others. (And yes, the fact that we even can communicate about doing this - and decide against it - is part of our dominance)

I'll admit it's a biased opinion but in my book we pretty much rule a pretty large chunk of this rock and do with it as we please.

The oxygen event is the counter-example to that - namely, another group of species (cyanobacteria) basically did go and kill off 90% of earth's species by making the atmosphere poisonous (e.g. ~20% oxygen rather than nearly devoid of oxygen).

[MLai]

That said, my own wild guess for the cognitive features necessary to start a runaway process is the development of symbolic/representational cognition. There seem to be different types of learning - a sort of Pavlovian stimulus-response is one type and its pretty common; the other however is something where the features of the world can be internally represented in a sort of modular fashion (symbols representing bits of the world) and furthermore can be exchanged or re-arranged to 'figure out' situations which the creature has never before directly encountered during their lifetime and for which they don't have an instinctual response.
Like tool use, that specific requirement is also not that special. Monkeys can do math.
In research, monkeys perform addition using numerical symbols. (http://www.livescience.com/44986-monkeys-do-math.html)

I don't consider sapience as some sort of sharp divide separating humans from animals. There is no line; it is a gradual spectrum of increasing intelligence.
Language is also not a magic button. Dolphins most certainly have complex syntax. We've already proven that their chatter is purposeful; we just aren't smart enough to translate it.
Even prairie dogs are smart enough to say "Watch out, fat human wearing yellow t-shirt incoming!" I don't think we need to wonder about dolphins.
http://www.treehugger.com/natural-sciences/researcher-decodes-praire-dog-language-discovers-theyve-been-calling-people-fat.html

And I think that there is indeed a great possibility that certain dinosaurs were as smart as Homo erectus, and under the right conditions could have evolved into civilization rather than mammals.
Your ability to play through Darksiders 2 proves you can solve puzzles ravens can solve in less time! Achievement unlocked!

[NichG]

Like tool use, that specific requirement is also not that special. Monkeys can do math.
In research, monkeys perform addition using numerical symbols. (http://www.livescience.com/44986-monkeys-do-math.html)

I don't consider sapience as some sort of sharp divide separating humans from animals. There is no line; it is a gradual spectrum of increasing intelligence.
Language is also not a magic button. Dolphins most certainly have complex syntax. We've already proven that their chatter is purposeful; we just aren't smart enough to translate it.
Even prairie dogs are smart enough to say "Watch out, fat human wearing yellow t-shirt incoming!" I don't think we need to wonder about dolphins.
http://www.treehugger.com/natural-sciences/researcher-decodes-praire-dog-language-discovers-theyve-been-calling-people-fat.html

And I think that there is indeed a great possibility that certain dinosaurs were as smart as Homo erectus, and under the right conditions could have evolved into civilization rather than mammals.
Your ability to play through Darksiders 2 proves you can solve puzzles ravens can solve in less time! Achievement unlocked!

The outcomes are clearly different though, which is the thing that remains to be explained. Whatever feature or distribution of features it was, our species underwent a runaway process where the feedback on those features - biologically, culturally, whatever - continued to amplify them. Chimps, dolphins, prarie dogs, etc meanwhile, have not underwent this runaway process. That runaway process is the sharp divide in the data.

The question then is, where is the corresponding divide in the feature space? It could just be a matter of degree - average species intelligence of '70 units' doesn't have enough synergistic interactions to go runaway, but average of '80 units' does. That's a very weak hypothesis though, because it basically makes no real predictions about the nature of that particular transition.

Still, maybe this isn't in fact an individual-level phenomenon. So far its pretty clear that 'researchers can teach monkeys things that researchers can simplify sufficiently', but I wonder if that says more about the monkeys or the researchers? Teaching someone something is actually a very non-trivial task (and yes, there are animals that teach things to their young, but as far as I know those are generally very specific things); what if the monkeys can learn just fine, but the information degrades faster than their population grows when they try to teach it to their offspring (in the sense that fewer than one monkey per parent successfully learns it on average)? Maybe to see this, we really would need to take a tribe of monkeys, teach one generation to add and use symbols, and then see how that information behaves over the next couple generations; whether it was retained, or was lost.

It does suggest an interesting computational experiment too - rather than trying to evolve good individual cognitive abilities in simulo, try to evolve the ability to be taught and to teach via population-level pressures.

[MLai]

It does suggest an interesting computational experiment too - rather than trying to evolve good individual cognitive abilities in simulo, try to evolve the ability to be taught and to teach via population-level pressures.
So you're saying if the monkeys who learned math with numbers can teach their children how to do math with numbers (without researcher help) in order to get the cookies, then you'll be impressed?

[NichG]

So you're saying if the monkeys who learned math with numbers can teach their children how to do math with numbers (without researcher help) in order to get the cookies, then you'll be impressed?

No, then I'll have to look for a new hypothesis to explain the runaway process observed in humans. Its not about being impressed or not. Its about explaining the big honking signal in the data - the fact that we've built a globe-spanning network of cables, put stuff into orbit, etc, and are talking to eachother using quantum mechanical devices designed and built a few atoms at a time, whereas crows and monkeys - however sophisticated their intelligences might be - are still mucking around with twigs and stones. Its not that they just have slightly more primitive computers than we do or something, there's a clear gap in what the various species have actually produced and accomplished. That gap is the phenomenon that its pretty clear we only have a murky understanding for.

If it turns out that e.g. language, tool use, abstract symbolic thought, or social propagation of information over multiple generations can't be used to explain the gap, it means that we'd need to look elsewhere for the explanation.

[The Grue]

No, then I'll have to look for a new hypothesis to explain the runaway process observed in humans.

Given that the runaway process is your hypothesis, I don't think that's how it's supposed to work.

[Kato]

The oxygen event is the counter-example to that - namely, another group of species (cyanobacteria) basically did go and kill off 90% of earth's species by making the atmosphere poisonous (e.g. ~20% oxygen rather than nearly devoid of oxygen).
Who says they weren't the dominant species back then? :smallwink:
Still, they didn't plan to do it. Without derailing into another topic, we can make conscious decision to exterminate species, they most likely did it by accident.



Even prairie dogs are smart enough to say "Watch out, fat human wearing yellow t-shirt incoming!" I don't think we need to wonder about dolphins.
http://www.treehugger.com/natural-sciences/researcher-decodes-praire-dog-language-discovers-theyve-been-calling-people-fat.html


Impressive, but taking information from prairie dogs and projecting them on dolphins seems a bit of a jump. Yeah, I know, dolphins are generally regarded as very smart and without any basis I won't dispute that, but merely being able to communicate doesn't mean someone is highly intelligent. Intelligence is complicated. Maybe someone should figure out an animal SAT :smallsigh: :smalltongue:

[NichG]

Given that the runaway process is your hypothesis, I don't think that's how it's supposed to work.

Well, the gap is the data - namely that we've got computers, cars, skyscrapers, and the space shuttle, but the next closest thing we can find in animals is something like 'a bent wire' or 'a sharpened stone' or 'a digging stick'. That gap isn't a hypothesis, its observational fact. What is a hypothesis is the 'why' behind that gap - we've had a number in this thread, from omnivorism to language.

(Edited for clarity.)


Who says they weren't the dominant species back then? :smallwink:
Still, they didn't plan to do it. Without derailing into another topic, we can make conscious decision to exterminate species, they most likely did it by accident.


Well, this is why I say 'dominance' is a bad metric for this kind of question. They were the dominant species back then. By biomass, they are still the dominant species - there's about twice as much cyanobacteria as there is human in the world.

[Knaight]

Well, the gap is the data - namely that we've got computers, cars, skyscrapers, and the space shuttle, but the next closest thing we can find in animals is something like 'a bent wire' or 'a sharpened stone' or 'a digging stick'. That gap isn't a hypothesis, its observational fact. What is a hypothesis is the 'why' behind that gap - we've had a number in this thread, from omnivorism to language.

It's worth noting that for the vast majority of human history*, we didn't have this. It took a very long time to even get fairly basic stone tools, substantially longer to get any real tool making, etc. As such, we don't really know if it's even an intelligence gap - plenty of other species are where we were 100,000 years ago. There's a real possibility that they could figure out complex tools on their own, given time.

*Technically prehistory.

[Ravens_cry]

Even going pretty back, even to pre-history, Hominids, and, even more so, humans out tooled other critters. It's surprising when we see animals use tools, but they really don't compare at it compared to even the least developed tech of humans.

[NichG]

It's worth noting that for the vast majority of human history*, we didn't have this. It took a very long time to even get fairly basic stone tools, substantially longer to get any real tool making, etc. As such, we don't really know if it's even an intelligence gap - plenty of other species are where we were 100,000 years ago. There's a real possibility that they could figure out complex tools on their own, given time.

*Technically prehistory.

Well, I'm certainly willing to consider the proposition that whatever key features that emerged came about ten thousand years ago instead of a hundred thousand or a million. The thing is, we can't really go and do lab experiments on homo habilis or homo erectus to see exactly what the extent of their intelligence and social structure were; we're stuck looking at the various species that currently exist on modern earth, along with fairly limited archeological data on extinct things (in comparison to the sort of controlled behavioral experiments we can do on crows and chimps as have been discussed in this thread).

[shawnhcorey]

It's worth noting that for the vast majority of human history*, we didn't have this. It took a very long time to even get fairly basic stone tools, substantially longer to get any real tool making, etc. As such, we don't really know if it's even an intelligence gap - plenty of other species are where we were 100,000 years ago. There's a real possibility that they could figure out complex tools on their own, given time.

*Technically prehistory.


Even going pretty back, even to pre-history, Hominids, and, even more so, humans out tooled other critters. It's surprising when we see animals use tools, but they really don't compare at it compared to even the least developed tech of humans.

Stone tools are fairly recent, only about 1.5 million years ago. Before that, our ancestors were short and couldn't run. The question is how did they survive the carnivores of the open woodlands they lived in? They must have had tools of some kind to protect themselves, but what, nobody knows.

[Ravens_cry]

Stone tools are fairly recent, only about 1.5 million years ago. Before that, our ancestors were short and couldn't run. The question is how did they survive the carnivores of the open woodlands they lived in? They must have had tools of some kind to protect themselves, but what, nobody knows.

I believe even the earliest hominids are believed to have used stone tools, such as these (http://en.wikipedia.org/wiki/Olduwan), though I wouldn't be surprised if they used other, less preservable, tools.

[Miklus]

My book also claims that the human brain is asymetrical, that the two halves are specialized. This is supposed to explain why most people are right-handed. Chimps have an equal number of left- and right-handed individuals. This could have more to do with language than toolmaking, I suppose.

As to why more animals don't develop larger brains... Having a large brain comes at a huge cost. It takes a huge amount of protein and energy to run. Worst of all, the young are helpless for far longer than normal. A tiger can take care of itself at two years old, a human depends on the parents until the mid-late teens.

Most animals have the tools they need build-in anyway. It's only when some poor ape suddenly finds itself stranded on the savanna without trees that it have to think its way out of trouble.

[shawnhcorey]

My book also claims that the human brain is asymetrical, that the two halves are specialized. This is supposed to explain why most people are right-handed. Chimps have an equal number of left- and right-handed individuals. This could have more to do with language than toolmaking, I suppose.

No, it has to do with bigotry. Left-handed people are considered sinister and are abused by society. That's why there's so few of them.


As to why more animals don't develop larger brains... Having a large brain comes at a huge cost. It takes a huge amount of protein and energy to run. Worst of all, the young are helpless for far longer than normal. A tiger can take care of itself at two years old, a human depends on the parents until the mid-late teens.

A chimpanzee or bonobo needs 4 to 5 years before they can make it on their own. An orangutan needs 7 to 8 years.


Most animals have the tools they need build-in anyway. It's only when some poor ape suddenly finds itself stranded on the savanna without trees that it have to think its way out of trouble.

The great apes are hardly helpless without trees. Any predator that attacks a solitary ape runs the risk of a life-threatening injury.

[TSGames]

So disappointed that no one has answered with "black monolith".

The very first thing I did was to search the page for the word "monolith". I'm very glad that someone referenced it.

[hamishspence]

And I think that there is indeed a great possibility that certain dinosaurs were as smart as Homo erectus, and under the right conditions could have evolved into civilization rather than mammals.

Ground Hornbills followed a similar path - but not as far:

http://darrennaish.blogspot.co.uk/2006/08/bucorvids-post-cretaceous.html

[Frozen_Feet]

No, it has to do with bigotry. Left-handed people are considered sinister and are abused by society. That's why there's so few of them.


Uh, you got the causal link backwards. Left-handed people were considered sinister because there were so few of them in the first place. Handedness is a strongly genetic trait, and even in cultures where they are not discriminated against, left-handed people still make up at most 20% of the people.

More to the point, even if you were right about bigotry affecting the number of left-handed people, it would not explain why some people have dominant right or left hand in the first place. Natural ambidextirity is very rare and learning it takes a lot of effort. So the reason for either hand to be dominant almost certainly is linked to make-up of human brains.

[shawnhcorey]

Natural ambidextirity is very rare and learning it takes a lot of effort. So the reason for either hand to be dominant almost certainly is linked to make-up of human brains.

Although you can learn to be ambidextrous, natural ambidextrous is natural; you just do it. :smallsmile:

Humans are not the only ones who are handed. Most horses are left-handed; that's why you mount a horse on its left. Most birds are also left-handed. Handed goes back a long ways and is not just a human trait.

[Ravens_cry]

Heck, many molecules are handed, including many that make up our body. This even affects perception in unusual ways, with a certain molecule in one configuration smelling like spearment and in another like caraway.

[Eldan]

Heck, many molecules are handed, including many that make up our body. This even affects perception in unusual ways, with a certain molecule in one configuration smelling like spearment and in another like caraway.

Though that really has nothing to do with handedness in animals. It's just referred to by the same term. Molecules, after all, don't have hands. It's a configuration of bonds that can be mirrored.

[Ravens_cry]

Though that really has nothing to do with handedness in animals. It's just referred to by the same term. Molecules, after all, don't have hands. It's a configuration of bonds that can be mirrored.
True, but it's one of my favourite parts of chemistry and biology, how much shape matters once you get to the really small scale. You look at a single cell and each one is a metropolis of biochemical factories. You say nanotechnology, I say life, a far cry from the bag of protoplasm they were once thought.
I know, a tangent, but still awesome.:smallbiggrin:

[Mith]

My two cents for a start of sapience is a mirror test, and problem solving. Most mammals that I can think of fit that criteria. I had a pet goat who had his horns removed, since he was about face to face with me and horns are sharp. Since he couldn't scratch his back, he would look for the right sized stick and use it to scratch his back. Then he would eat it because he was a goat:smallbiggrin:

Anyways, the precise cause of sapience likely originates with brain size, and I would argue that either the drive for complex groups and scavenger mentality is more likely to gain results then a solitary carnivore.

[Frozen_Feet]

Brain-size is a flawed argument, because some of the most intelligent animals we know of are birds, with, well, bird-brains. It would be more accurate to talk of brain-size in proportion to body mass, as that has much stronger correlation with cognitive ability. Even then, the structure and inner workings of the brain are important factors, as evidenced by cognitive variance within humans. Some handicapped people have brains of average size, but still don't mentally advance past childhood. This creates an interesting comparison point with several mammals that are estimated to be on par with human children, like pigs to give an example.

[Ravens_cry]

Brain size may matter, just not in the ways we think. Still, correlation is not causality. Heck, Neanderthal's had bigger brains than us, and while they were no dummies, they weren't quite us either.

[MLai]

Brain size may matter, just not in the ways we think. Still, correlation is not causality. Heck, Neanderthal's had bigger brains than us, and while they were no dummies, they weren't quite us either.
I don't think the decline of Neanderthals had much to do with their "intelligence."

[Spiryt]

Brain-size is a flawed argument, because some of the most intelligent animals we know of are birds, with, well, bird-brains. It would be more accurate to talk of brain-size in proportion to body mass, as that has much stronger correlation with cognitive ability. Even then, the structure and inner workings of the brain are important factors, as evidenced by cognitive variance within humans. Some handicapped people have brains of average size, but still don't mentally advance past childhood. This creates an interesting comparison point with several mammals that are estimated to be on par with human children, like pigs to give an example.

Well that's kind of like saying that engine displacement doesn't matter, because carburettor is dead etc. though. :smallwink:

Everything matters, and brains-size does as well, among other things.

[shawnhcorey]

Well that's kind of like saying that engine displacement doesn't matter, because carburettor is dead etc. though. :smallwink:

Everything matters, and brains-size does as well, among other things.

A motorcycle can out preform a Mac truck but its engine displacement is considerably smaller. Relative size is more important than absolute size.

[NichG]

Brain size/relative brain size may be a necessary condition of achieving certain behaviors, but its not really a plausible 'cause' in its own right, since we know that brains aren't just homogeneous lumps of tissue - they're structurally differentiated, and there are different brain regions that are represented to different degrees in different species. Having a big brain might be necessary in order to fit in more different functions, but you still need to figure out what those particular functions are.

Its sort of like saying that the cause of being able to run certain computationally costly modern apps is that your phone has 'more transistors these days'. Its related, but its not really the cause per se - its whether or not those transistors have been used to make a faster CPU or add a GPU or whatever.

[Ravens_cry]

Well, there must be a reason they did get bigger, in our kind of intelligence any way, as having a huge brain with such a small body has many disadvantages. It has large relative feeding requirements and it causes all sorts of havoc during birth, for example.

[Spiryt]

A motorcycle can out preform a Mac truck but its engine displacement is considerably smaller. Relative size is more important than absolute size.

Motorcycle absolutely won't outperform truck as far as pulling or carrying anything goes...

But brain=engine was of course very abstract comparison, and I fully agree that brain has to 'just' be big relative to the whole body.

Still it most probably has to be of certain size for high intelligence and sapience.

Even very small people still have big, human sized brains, after all.

[Knaight]

Heck, many molecules are handed, including many that make up our body. This even affects perception in unusual ways, with a certain molecule in one configuration smelling like spearment and in another like caraway.

As has been stated above, chirality is very much not the same thing as handedness in animals (including people). That said, carvone is pretty excellent, and a good example of chirality where both results are actually nice.

[Ravens_cry]

As has been stated above, chirality is very much not the same thing as handedness in animals (including people). That said, carvone is pretty excellent, and a good example of chirality where both results are actually nice.
Yeah, I know. Bit of an off topic, but still, yes, nice.