Ape Evolution

[HappyCoder]

Just a quick note of clarification...

 

As soon as there is evidence against something in science it is adapted to fit the new evidence... things tend not to be wrong, just incomplete...

 

My take on what is science....

 

Yes. A little after posting this I realized I probably sounded like I was trying to imply that evolution could be false. Imcomplete is probably a better wording than wrong. Thank you for pointing that out.

[CDarwin]

Australopiths from 2-6 million years ago, Homo after that.

 

6 mya is a little old. More like 4. The known hominid genera preceding that were Ardipithecus, Orrorin, and Sahelanthropus. And of course the transfer from Australopithecines to Homo wasn't instantaneous.

 

If I might pile pedantry on pedantry.

[SkepticLance]

Phi for All said

 

"and now I know why creationists keep using this argument. You keep giving them permission to use it with statements like this. Sometimes clarification is really just equivocation in an ape suit."

 

I do not want to be pedantic, but denying that humans evolved from apes is denying scientific truth. Humans are part of the Great Ape taxonomic group, and our ancestors were also apes. I don't care what arguments creationists use. We should not deviate from telling it as it is.

[Daecon]

When someone says "ape" people assume to be referring to today's modern apes.

 

While the common ancestors were technically apes, they aren't "apes" as the word is used to describe specific creatures of today.

[ecoli]

6 mya is a little old. More like 4. The known hominid genera preceding that were Ardipithecus, Orrorin, and Sahelanthropus. And of course the transfer from Australopithecines to Homo wasn't instantaneous.

Apologies, you're right about being early on the 6 million mark... but I was taught that human evolution around 2 million years ago probably did occur (relatively) rapidly.

[Luminal]

Will modern apes evovle into Humans? If evolution is true then at some point this should happen.

 

Of course, because we all know evolution can only occur in a single direction. It's not as if modern apes are well suited for survival in their particular habitat and humans for theirs or anything silly like that.

 

It is a fortunate fact indeed that all Europeans eventually emigrated to the Americas, or it might make your entire presupposition seem absurd.

[iNow]

All right, everyone has stated that humans come from apes. Now the 2nd question. Will modern apes evovle into Humans? If evolution is true then at some point this should happen.

 

 

From someone who knows much more about this than me or you:

 

[CDarwin]

Apologies, you're right about being early on the 6 million mark... but I was taught that human evolution around 2 million years ago probably did occur (relatively) rapidly.

 

But it overlapped the Australopithecines by a good bit. Homo stretched from around 2.5 mya to now, while the robust Australopithicines continued until about 1.2 mya.

[ecoli]

But it overlapped the Australopithecines by a good bit. Homo stretched from around 2.5 mya to now, while the robust Australopithicines continued until about 1.2 mya.

Robust, but "inferior" to Homo in their throwing ability. I'm actually a little surprised that Australopiths were able to hang around even that long.

 

ps - in case you didn't get the hint, I curious for a source on that.

[CDarwin]

Robust, but "inferior" to Homo in their throwing ability. I'm actually a little surprised that Australopiths were able to hang around even that long.

 

ps - in case you didn't get the hint, I curious for a source on that.

 

Oh, sure. http://www.archaeologyinfo.com/species.htm Good ol' Archaeology Info would do the trick.

 

I've never heard any comparisons of the two genera's throwing capacity. Personally, I find it more surprising that the robusts didn't last longer than they did. They were well adapted to a life in the forest edge, and there continued to be forest edges even after they went extinct. My best guess would be competition with baboons did them in.

[Rev Blair]

Will modern apes evovle into Humans? If evolution is true then at some point this should happen.

 

Why should this happen? Evolution is not some directed thing where every species can be expected to go through some hierarchy of development until they become us. Instead, it is more or less random...some trait is favourable under some conditions so individuals with that trait breed more.

 

That's a gross oversimplification on my part, I know, but no other species is going to evolve into humans. Maybe they'll develop bigger brains or become bipedal. Maybe not. Whether they do or not though, they are in no way on a path to evolving into humans.

[ecoli]

Oh, sure. http://www.archaeologyinfo.com/species.htm Good ol' Archaeology Info would do the trick.

 

I've never heard any comparisons of the two genera's throwing capacity. Personally, I find it more surprising that the robusts didn't last longer than they did. They were well adapted to a life in the forest edge, and there continued to be forest edges even after they went extinct. My best guess would be competition with baboons did them in.

 

It's interesting that you've never heard this comparison. I'm taking a class, the professor of which proposes that Homo's ability to throw is the basis for human uniqueness.

 

It's an interesting theory (and I think it's probably the correct one): http://en.wikipedia.org/wiki/Paul_M._Bingham

[CDarwin]

It's interesting that you've never heard this comparison. I'm taking a class, the professor of which proposes that Homo's ability to throw is the basis for human uniqueness.

 

It's an interesting theory (and I think it's probably the correct one): http://en.wikipedia.org/wiki/Paul_M._Bingham

 

Interesting. It's an umbrella theory, though, and those have the problem of explaining why the major characters of human uniqueness (bipedality, enlarged brains, speech) appeared at such widely spaced times. There's also always the "why not chimpanzees" problem. This is what Craig Stanford's theories run into a lot. Chimps throw too; why wouldn't improved throwing ability translate into better ability to control cheaters and thus be selected for in them as well?

 

But I'm just going off a paragraph in a Wikipedia article. I'll try scouring the databases.

[SkepticLance]

I have a personal 'umbrella' theory too. I think that technology drove evolution from apes into humans. Began with our ape forebears, with a tribe of apes adopting simple technology - rather like that which modern chimps use. Maybe banging stones to break nuts, or using wooden skewers to dig bugs out of rotten wood, or something similar.

 

The difference is that the ape tribe that became our forebears hung onto and developed the basic technology, and became dependent on it for survival. That meant that those best adapted to the use of tools were the ones to pass on their genes. This leads to bigger brains, upright stance, good manipulative fingers etc. Other consequences of technology (after millions of years of evolution) include the use of alternative means of keeping warm (clothing, fire, sleeping under straw) which would permit the loss of hair, and the benefits that come from loss of hair. Use of fire and cooking permits the reduction in gut size etc.

 

Of course, this is a simplified picture and the drivers of human evolution would include other factors. However, it makes sense to me that the main thrust leading to the evolution of that unique species called Homo sapiens was the use of ever more complex technology and adaptations to use technology plus adaptations that came from the benefits of technology.

[PhDP]

Human uniqueness, what an arrogant concept. We're a pretty normal species in a group that was not especially successful (primates), within a big clade that's also not very successful (mammal).

 

I'm not surprised that CDarwin has never heard of the theory, Bingham published very little about his theory, and he wasn't cited often.

[SkepticLance]

To Phil

 

I stand by my claim of human uniqueness. We are a very strange ape!

 

We are the only terrestrial mammal in our size range that is functionally hairless. We have the biggest primate brain - by far. We are the only truly upright ape. We have the strongest legs and weakest arms for our size of any ape. We have the smallest gut for our size of any primate. We are the only primate able to run long distances. In fact, for human athletes our stamina is better than almost any other mammal (major exception being the horse). We are the only primate with complex language. The only ape that forms long term (mainly) monogamous pair bonds. etc etc.

[HappyCoder]

The difference is that the ape tribe that became our forebears hung onto and developed the basic technology, and became dependent on it for survival. That meant that those best adapted to the use of tools were the ones to pass on their genes. This leads to bigger brains, upright stance, good manipulative fingers etc. Other consequences of technology (after millions of years of evolution) include the use of alternative means of keeping warm (clothing, fire, sleeping under straw) which would permit the loss of hair, and the benefits that come from loss of hair. Use of fire and cooking permits the reduction in gut size etc.

 

So evolution contributes to technology, technology contributes to evolution. That makes sense.

[CDarwin]

The difference is that the ape tribe that became our forebears hung onto and developed the basic technology, and became dependent on it for survival. That meant that those best adapted to the use of tools were the ones to pass on their genes. This leads to bigger brains, upright stance, good manipulative fingers etc. Other consequences of technology (after millions of years of evolution) include the use of alternative means of keeping warm (clothing, fire, sleeping under straw) which would permit the loss of hair, and the benefits that come from loss of hair. Use of fire and cooking permits the reduction in gut size etc.

 

That's an older idea, actually. Darwin first proposed it in The Descent of Man, before there was an extensive fossil record. The problems are A) Why not chimps? and B) How do you explain the big distances in time between events? The earliest humans didn't have particularly large brains. In fact it was Homo erectus before brain size began to expand independant of increase in body size. They also didn't have fingers totally well adapted to manipulation.

 

Personally, if I might comment, I tend to think of the major events of hominid evolution as having happened for seperate reasons in different ecological contexts. Bipedality was perhpas a slightly more efficient form of locomotion that knuckle-walking in the forest edge environment that early humans colonized, for example. Stone tools were advantageous to exploit food resources there like ungulate carcasses and tubers that wouldn't be as important or available to arboreal apes in the deep forest.

 

As for explanations for human intelligence, I tend to prefer social theories like Bingham's to technological ones. I would submit that what makes humans 'special' is less our advanced reasoning skills than our advaced communication skills. Stone tools weren't made in a day. They required complex social units passing information from generation to generation and from population to population. Human brains are fine-tuend for intelligent communication with other brains. Culture may not be uniquely human, but it is by far our greatest weapon.

 

We are the only truly upright ape. [/Quote]

That depends on how you want to define "truely upright." Gibbons spend almost their entire lives upright. Humans are the only apes that are upright like humans, it's true.

 

The only ape that forms long term (mainly) monogamous pair bonds. etc etc.

 

Eh... gibbons form serial monogamous pair bonds, which is the type that most "monogamous" humans tend to form as well (divorce and remarraige). The majority of human cultures are actually polygynous (usually only for those who can afford more than one wife). So I don't know if you can really say much about monogamy being a uniquely human trait. Different theorists had made way too much out of what is basically a cultural practice (and a pretty rare one at that).

 

Humans are certainly different. You can't get around that. But we're not necessarily more different than many other species.

[CharonY]

Also you can derive more or less unique feature from about every species. In a way you can state that every species is unique, but I assume that does not really say much.

[SkepticLance]

To CDarwin

 

I don't want to over-state my 'umbrella' theory. Certainly evolution is a complex process, and many variables are likely to be involved. However, I think adaptation to an increasing facility with technology has to be one of the most important.

 

Why not chimps? I suspect the difference was pure luck. One tribe of early ape was subject to a set of circumstances that led to advancing technology and the chimps forebears were not. Luck plays a role in evolution that is often underestimated.

 

You also need to understand what I mean by technology. Chimps have technology when they bang the stones together to crack nuts. I suggest our early forebears simply developed a range of such techniques. They became, through evolution, expert tool users, but remained inexpert tool makers until much later in evolution.

 

Upright gibbons? Yes, but not upright supported by hind legs, most of the time, as humans do. Gibbons have highly developed arms and use them to support the body more than legs. When I said 'most upright' I meant in the way designed to free the arms and hands for tool use.

 

Monogamy for humans. It is, of course, not perfect, but is unusual for primates. I doubt it is simply cultural. The habit is too widespread. Name me a culture where most women do not want a husband or equivalent.

 

All species are unique in some way. Correct. But no other primate is as unique in as many ways as humans. I see no problem with being proud of our uniqueness and abilities as a species.

[ecoli]

Personally, if I might comment, I tend to think of the major events of hominid evolution as having happened for seperate reasons in different ecological contexts. Bipedality was perhpas a slightly more efficient form of locomotion that knuckle-walking in the forest edge environment that early humans colonized, for example. Stone tools were advantageous to exploit food resources there like ungulate carcasses and tubers that wouldn't be as important or available to arboreal apes in the deep forest.

Yet, bipedalism can't completely account for human uniqueness, because we can see that Australopiths aren't around anymore, and it doesn't confer any special advantage to bipedal birds either.

 

As for explanations for human intelligence, I tend to prefer social theories like Bingham's to technological ones. I would submit that what makes humans 'special' is less our advanced reasoning skills than our advaced communication skills. Stone tools weren't made in a day. They required complex social units passing information from generation to generation and from population to population. Human brains are fine-tuend for intelligent communication with other brains. Culture may not be uniquely human, but it is by far our greatest weapon.

I would agree. Technology is not unique to humans, but the scale at which we produce them are. The scale of technological production is directly related to the scale of our social cooperation.

This trend is not only seen on an evolutionary timescale, but in recent recorded history as well.

 

Eh... gibbons form serial monogamous pair bonds, which is the type that most "monogamous" humans tend to form as well (divorce and remarraige). The majority of human cultures are actually polygynous (usually only for those who can afford more than one wife). So I don't know if you can really say much about monogamy being a uniquely human trait. Different theorists had made way too much out of what is basically a cultural practice (and a pretty rare one at that).

Humans aren't always social monogamists. The historical record shows (and I've learned this from Bingham as well) that sexual promiscuity in humans (polyandrogany) was common during periods of scarce resources. By obscuring paternity, female mothers forces are large pool of males to contribute resources to raising her children.

 

Humans are certainly different. You can't get around that. But we're not necessarily more different than many other species.

Not more different, but different in different ways... at a species of 7 billion members, where the only species that makes structure visible from space, that can concsiously affect the existence of millions of other species, change the climate of our planet... If human behavior isn't unique, than nothing is.

 

I'm not surprised that CDarwin has never heard of the theory, Bingham published very little about his theory, and he wasn't cited often.

 

Yet the correctness of a theory is not necessarily an indication of how often its cited. As theories go, this one is in the early stages. If it continues to stand up to the evidence, than I'm sure Bingham will work on promoting it (thousands of students take his class each year and it's offered as an online course to international students as well... so I guess he's going with the direct educational route).

[Paralith]

Monogamy for humans. It is, of course, not perfect, but is unusual for primates. I doubt it is simply cultural. The habit is too widespread. Name me a culture where most women do not want a husband or equivalent.

 

That question doesn't really support monogamy, Lance. Of course human women want husbands. But do they want one husband all to themselves for the rest of their lives, or will they be happy to be the second wife to a rich and influential husband? Monogamy may be widespread in modern times, but behaviors that only became more prevalent recently are not good representatives of the majority of our evolutionary history. I think humans, like many other animal species, including other primates, are facultatively polygamous, with the current environment favoring the option of monogamy.

 

All species are unique in some way. Correct. But no other primate is as unique in as many ways as humans. I see no problem with being proud of our uniqueness and abilities as a species.

 

I see a problem with it. As a scientist this opinion will tend to color your observations with the subjective bias of humans being somehow more special and/or more important than other life on this planet, which biologically is simply not the case. In point of fact, this opinion that has existed for most of human history has biased primate research to those primates which are most similar to humans, and to looking for characteristics in them that are most similar to what we understand.

 

Besides, are you even familiar enough with the intimate characteristics of all the other primate species to say with certainty that they all lack a human-sized amount of relatively unique qualities? Also, humans may be the only hominid around today, but remember all those extinct species that make up the Homo genus. Many of the characteristics that most clearly separate humans from other animals were also had by those extinct relatives of ours.

[ecoli]

I think humans, like many other animal species, including other primates, are facultatively polygamous, with the current environment favoring the option of monogamy.

yup... we're monogamous when times are good. This behavior is common in animal species.

 

I see a problem with it. As a scientist this opinion will tend to color your observations with the subjective bias of humans being somehow more special and/or more important than other life on this planet, which biologically is simply not the case. In point of fact, this opinion that has existed for most of human history has biased primate research to those primates which are most similar to humans, and to looking for characteristics in them that are most similar to what we understand.

 

Besides, are you even familiar enough with the intimate characteristics of all the other primate species to say with certainty that they all lack a human-sized amount of relatively unique qualities? Also, humans may be the only hominid around today, but remember all those extinct species that make up the Homo genus. Many of the characteristics that most clearly separate humans from other animals were also had by those extinct relatives of ours.

 

Biologically, we aren't that unique, yet those differences has led to an animal who's scale of non-kin dependent social cooperation has definitely made a unique mark on the planet. so, we are not unique biologically... our physiology is not that special. Our brains are special, but only because small physical changes has allowed us to cooperate on great scales.

[CDarwin]

I don't want to over-state my 'umbrella' theory. Certainly evolution is a complex process, and many variables are likely to be involved. However, I think adaptation to an increasing facility with technology has to be one of the most important.[/Quote]

 

Probably, yes. For some factors of human evolution.

 

Why not chimps? I suspect the difference was pure luck. One tribe of early ape was subject to a set of circumstances that led to advancing technology and the chimps forebears were not. Luck plays a role in evolution that is often underestimated.

 

But the selective pressure for better tool use is there among chimps already. Yet there has been no pressure for bipedality from it, there has been no pressure for particularly weighty brains because of it, and there has been no pressure to develop more dexterous hands. Why? You've also skirted my point about the timing of events. Why did bipedality proceed enlarged brains by 5 million years if they both had the same driver?

 

There's a satirization of umbrella theories offered in Man the Hunted called "Man the Dancer." I'll elaborate when I get back.

 

Upright gibbons? Yes, but not upright supported by hind legs, most of the time, as humans do. Gibbons have highly developed arms and use them to support the body more than legs. When I said 'most upright' I meant in the way designed to free the arms and hands for tool use.

 

When gibbons walk on the ground they do so bipedally on their hind limbs. But like I said, you're right that only humans are upright like humans. I'm not arguing. I would argue that bipedality is "designed to free the arms and hands for tool use" because there's no evidence for that.

 

Monogamy for humans. It is, of course, not perfect, but is unusual for primates.

Titi monkeys do it (more consitently that humans). Gibbons, as I said. There are other examples from the prosimians.

 

I doubt it is simply cultural. The habit is too widespread.

 

It appears widespread, but the majority of cultures practice simultaneous polygamy in some circumstances and almost all the ones that don't practice serial polygamy.

 

Name me a culture where most women do not want a husband or equivalent.

 

That's not the same as monogamy. Every chimp female wants to be in a group too. Every gorilla female wants to be in a troop with a male.

 

All species are unique in some way. Correct. But no other primate is as unique in as many ways as humans. I see no problem with being proud of our uniqueness and abilities as a species.

 

I don't think it's a terribly important issue which species is more "unique," but consider tarsiers.

 

They leap on hindlegs twice as long as their forelegs and longer than their bodies. They have eyes larger than their brains and heads that can rotate like an owl's. They are the only primates to subsist entirely on animal matter. They are the smallest primates taken as a group. They posses a fused tibia and fibula. They have a partially enclosed eye socket and dry nose like a monkey but the tiny brain and primitive body of a prosimian. And they have a bony canal surrounding their auditory meatus like an Old World Monkey even though they can't be uniquely related to them. Weird, weird little animals.

 

I'll get to ecoli when I get back from moving rocks. Bleh.

[SkepticLance]

Paralith said

 

"Of course human women want husbands. But do they want one husband all to themselves for the rest of their lives, or will they be happy to be the second wife to a rich and influential husband?"

 

As a woman, you can answer that one better than I can. No woman truly understands men, and no man truly understands women. A terrible generalisation, I know, but true to a degree. So I ask you ; "Is being a co-wife as desirable for a woman as being a sole wife?" If the answer is yes, I am going hunting for my number two!

 

Paralith also said

 

"I see a problem with it."

 

It is perfectly possible to be proud of something and also research it dispassionately. Blindness is overcome with professionalism. Besides which, anthropology is not my professional activity. I am involved in industrial chemistry and microbiology. It pays more!

 

CDarwin asked

 

"Why did bipedality proceed enlarged brains by 5 million years if they both had the same driver?"

 

Since we have a lack of facts, there is no obvious answer. However, I am going to offer an outrageous and shameless speculation instead. Please don't shoot me!

 

The difference between chimps and pre-humans could have been something as simple as the retention of tools. Imagine our forebear using a stone to smash rotten wood for grubs. By pure chance, it happens to be a very superior stone. Instead of throwing it away, the ape hangs onto it and carries it along. The advantages of always having a superior tool with oneself become apparent and the entire tribe gets into the habit of carrying their favourite tool, and this continues for mutiple generations. This ties up one hand - no longer suitable for locomotion, hence driving adaptation to more upright stance and bipedal locomotion. However, it would not, immediately, necessarily drive evolution of a larger brain.

 

OK. Terrible speculation, but at least it shows that there are possible explanations. Beside, speculating can be fun.

 

CDarwin said :

 

"I don't think it's a terribly important issue which species is more "unique,"

 

Nor do I. However, I mention it only to support my case that there is a special and unique driver for human evolution.