Originally posted by C Elegans
ROFLMAO Hi Gwally Since I think you're far more knowledgable than I am about hominid evolution, I'd be interest in your opinion of the finding of the Toumai skull.
I am hardly and expert, but here goes.....
I am struck by the fossils that were found – a jaw fragment, cranium, and some teeth. Heh, heh. Just what was found with Piltdown! I assume these were in better context….
What we have to remember is that Chimps are just as evolved as Humans. They didn’t stop evolving millions of years ago just because we split off from them. No, the common ancestor of chimps and humans would have to be somewhat different from both. Even though the author of the Nature article that CE posted ascribes to homoplasy (first paragraph, second post), he still expects that an early hominid will have smaller canines and larger brains than the early ancestor of the chimps (last two paragraphs of first post). That small contradiction aside, he goes on to make his case for homoplasy based on this skull. Yes, paleoanthropologists can predict general characteristics of theorized ancestral populations, but specific characteristics (size of brow ridge, size of canines) require evidence.
Does the Toumai skull push the date of the Chimp/Human ancestor back to 6 or 7 million years? Maybe. But if homoplasy and adaptive radiation are taken to the extreme, it is possible that the forerunner of the chimp once had a larger brain, smaller canine, and more upright posture, and that 6 million years of adaptation to the Chimp’s econiche has brought it to where it is today. The Chimp/Human common ancestor may
post-date Toumai. Its geographic location apart from other early hominid fossils (last paragraph, CE’s third quote-post) could just as easily prove my point as well as theirs.
Concerning the “missing link.” My physical anthropology teacher told me that there was no such thing as a missing link. That was 18 years ago when he said that. Humans and Chimps are already sufficiently linked through fossil evidence. They are only now quibbling about
which fossils form the most direct link.