Evolution without mutation

We can find living chimpanzees, even though they are endangered, or fresh bones of dead chimps. But researchers have not found fossils of their (direct) ancestors.

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satt_fs wrote:

rosborne979 wrote:
satt_fs wrote:
It is quite a disturbing fact that any fossils of chimps are not found yet.

Why?

Multiple fossils of Australopithecus to Cro-Magnons have been found, but fossils of chimps are not. I think this is very strange.

The recent fossil record of humans is itself quite sparse. The volume written about wat fossils we do have makes it seem like they are abundant, but I've read that all of the early hominid fossils could be laid out on a reasonably large dining room table. Chimps of the same vintage -- assuming they were reasonably similar to what they are today, which is really a pretty big assumption -- would have been limited in their range and numbers by the availability of suitable habitat: they need trees. It may well be that hominids outnumbered African great apes throughout the separate histories of the bunch -- and still there are only a few hominid fossils to show for it.

There is also the possibility that chimps and gorillas descended from a so-called "hominid" ancestor -- that is, one that walked upright and returned to an arboreal existence when tropical forests recovered during one of the interglacial periods of recent geological history. Admittedly, it sounds (and may well be) far-fetched, but there's not much to contradict the conjecture. And we have a bunch of groups of early upright-walkers that clearly didn't evolve into humans.

It's an interesting puzzle, to be sure...

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satt_fs wrote:

We can find living chimpanzees, even though they are endangered, or fresh bones of dead chimps. But researchers have not found fossils of their (direct) ancestors.

I always assumed that since they weren't looking for fossil chimps, that when they found them they simply tossed them aside.

As far as I know, there hasn't been any attempt to find fossil chimps, so I guess I'm not surprised that none have been found (or at least reported).

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rosborne979 wrote:

I always assumed that since they weren't looking for fossil chimps, that when they found them they simply tossed them aside.

I don't think so. An anthropologist told me about the fact. If anthropologists are aware of the current absence of fossils of chimps, it is very unlikely that they should simply throw them away, if any.

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satt_fs wrote:

rosborne979 wrote:
I always assumed that since they weren't looking for fossil chimps, that when they found them they simply tossed them aside.

I don't think so. An anthropologist told me about the fact. If anthropologists are aware of the current absence of fossils of chimps, it is very unlikely that they should simply throw them away, if any.

It's the first I've ever heard of such a concern (other than from you, and you have expressed this concern several times). Are there many in the anthropological community who think the lack of chimp fossils is interesting, or is it just a minor curiosity, like why there aren't any mouse fossils, or gibbon fossils, or squirrel fossils?

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I read quite a bit about it (the lack of chimp/gorilla/gibbon fossils) relatively recently, from a book by a pair of molecular anthropologists (that is, not fossil fetishists). They've dated the human/chimp/gorilla split to a little under 4 myo, and there is no known fossil evidence of chimps or gorillas during this time.

These are the folks who posited the alternative conjecture -- chimps and gorillas evolving from a bipedal ancestor -- I mentioned above. They don't push the idea hard, just mention it as something that is consistent with the existing fossil record, which has lots of varieties of bipedal apes in Africa over the past 4 million years, but no clearly arboreal apes until (for all intents and purposes) modern times.

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patiodog wrote:

I read quite a bit about it (the lack of chimp/gorilla/gibbon fossils) relatively recently, from a book by a pair of molecular anthropologists (that is, not fossil fetishists). They've dated the human/chimp/gorilla split to a little under 4 myo, and there is no known fossil evidence of chimps or gorillas during this time.

These are the folks who posited the alternative conjecture -- chimps and gorillas evolving from a bipedal ancestor -- I mentioned above. They don't push the idea hard, just mention it as something that is consistent with the existing fossil record, which has lots of varieties of bipedal apes in Africa over the past 4 million years, but no clearly arboreal apes until (for all intents and purposes) modern times.

Ah, I see. So they need some fossil chimps to determine where the split occured. And hopefully to support their idea that the great apes derived from the hominid line.

If I had to guess why chimp fossils are less abundant than hominid fossils (which are already exceedingly rare), I would guess that the living population of chimps was relatively smaller than the various hominid lines, and therefor, fewer chiimp fossils.

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Yeah, that's my thought as well. But if, say, Australopithecus robustus was actually a gorilla ancestor - how cool would that be?

Might lead to changes in policy on primate research, though...

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patiodog wrote:

Yeah, that's my thought as well. But if, say, Australopithecus robustus was actually a gorilla ancestor - how cool would that be?

Why? I guess I'm not up to date on my linneages... is A.Robustus considered to be a direct human ancestor?

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patiodog wrote:

But if, say, Australopithecus robustus was actually a gorilla ancestor - how cool would that be?.

A nice fantasy. :wink:

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rosborne979 wrote:

patiodog wrote:
Yeah, that's my thought as well. But if, say, Australopithecus robustus was actually a gorilla ancestor - how cool would that be?

Why? I guess I'm not up to date on my linneages... is A.Robustus considered to be a direct human ancestor?

No. It's generally considered to be a dead end. Truth be told, though, the fossil record is so scanty that we don't know what specimens are dead ends. It's all highly conjectural.

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whoa whoa. We have plenty of apes and "chimp" fossils. Its just that the times that these critters represent,make the fossil record smewhat incomplete. We dont usually find arboreal and forest floor dwelling fossils because the bones atre scattered and decay in a humic environment. However, if you look up fossils like "proconsul" (of which there are about 20 species), Moropithecus,Dryopithecus, Kenyapithecus, and Aegyptopithecus, Im sure youll find that there is fossil evidence from before about mid Miocene and a bit later into the early Pliocene.
"pithecus" means ape, so AUstralopithecus is an ape "southern ape", so its not a stretch at all.
A dark little secret of hominid paleo is that everybody who works on pongids(apes) is desirous of getting their own specimen named as unique. Ive never seen but one proconsul and , Ive been told that if you see one the others dont differ by more than intra species variation or what we commonly term intra polymorphism. I dont have any of my references handy, so Im winging it here . However, you should google "proconsul" and maybe the web has some fossils from musea..

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Dryopithecus (don't know about the others, though I think Aegyptopithecus fits in here, too) is so old that it could be a common ancestor of all the apes -- us included -- or a related dead end ---- if you go by the date of the man/ape split got from the molecules. Trouble is, the molecule people and the bone people are several million years apart on this.

Correct me if I'm wrong, though, but doesn't Dryopithecus have the typical primate shoulder -- oriented downward, like a baboon, rather than outward, like man, apes, gorillas, and gibbons? If so, then the remarkable shoulder that belongs so uniquely to the so-called "brachiators" would have had to evolve at least twice -- and possibly more, if dryo et al. are not regarded as ancestors of all the nonhuman great apes.

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hey, I said I was wingin it here. I was just dumping names from the Peabody list I have burnt into memory. (I have little need for pongid fossils). The important thing was that theyre all Miocene to early Pliocene with fossils about 14 to 20 MYA. Proconsul species were given the pongid linneage titles. (Mostly from teeth and skull casts. Maybe proconsul will provide more.

The fact that their environments were mostly humic forests, doesnt bode well for fossilization. Ive never looked at the conditions that seemed to favor proconsul specimens

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No, it doesn't. The earlier fossils fit very nicely with the old scheme that has apes and man branching about 26 million years ago. The molecular date -- which, so far as I can tell, has been very finely calibrated -- is at around 3.7 million years ago. No news from chimps, gorillas, or bonobos since then.

(I wonder, given similar environment, if we have anything on orangs -- 12 million years ago, by the DNA, if memory serves -- during the same period. Mayhaps it's time to do a bit of reading...)

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Heres one that looks like some exciting summer reading. I know these folks, theyve made a lifes work from proconsul.
Webpage Title

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and yet another

The issue of constant mutation rates has been tested and Paabos Neanderthal has been calendrically re-evaluated based upon a limited neandergenome hunt. Im gonna get me some references on allomorphic differentiation and population divergence among differing yet related species. I think stuff like insects and small mammals and birds should be well studied by now, do you know any refs that arent front loaded with intros to population genetics?

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Didn't realize there was such a late pre-man/ape candidate fossil. Cool.

Looking over a couple of bibliographies to see if I can track down a good reference...

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Here's something on the topic -- not exactly on target, but something... Not feeling sharp enough to really look into it right now.

PDF here

Search with link to PDF here -- first record is the relevant one

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Very, very odd thinking - we need a fossil chimp to disprove the 'spontaneous' creation of the chimpanzee?

I will reiterate what someone a lot smarter than me (and there are plenty of candidates) wrote recently. If there was a complete fossil record we would have no problem in verifying our origins. And, if there was NO fossil record the application of Darwin's theory (and the use of DNA testing these days) would STILL make it obvious.

Lucky us. We have both. Two paths leading straight to the same conclusion.

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Evolution without mutation

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