A small number of DNA samples from Neandertals about 30,000 years ago, when they were probably sharing territory with humans, seem to be clearly different from modern humans (about 25% as different from humans as chimps are).This is what I wasn't able to find. Thank you, Rick. Everywhere I looked just seemed to talk about the differences in skulls, etc., but then there would be notes about some of the "Neandertal" defining features still being extant in (some) homo sapiens, today.
But there was a strange thing just a few weeks ago. Someone managed to extract DNA from a 100,000 year old Neandertal. The DNA was clearly different from humans, and clearly similar to the previous Neandertal samples. But oddly, the older sample was MORE differnt from humans than the younger samples. This is not what you would expect if the two species had split prior to 100,000 years ago (the usual estimate is about 300,000) continued to evolve on their own paths. That one old DNA sample might be unrepresentative. Or there might have been mixing. Or there could be a third group mixing with the other two. Or the whole molecular clock thing could be flawed.I want to make sure I understand, because DNA stuff is so fascinating to me. To restate: So if they'd split X100,000 years ago, we would have expected the 100,000 year old Neandertal DNA to be more similar to humans, than later Neandertal DNA, because 100,000 was closer to the split (to the common ancestor)?
I agree with Cindy that the statements based on mitochondrial DNA tend to be too bold for the evidence. Her question, different species or different subtype, is hard to answer, because no one has extracted DNA from our common ancestors or from other ancient groups thought to be close enought to be in our own species (the desert is cruel to DNA). We really have no standard of how different DNA has to be to be a different species. So the opinions are stronger than the data.So some of it is a judgment call, then? I always wonder about stuff likethat, and I suppose unless/until some specimen loses or grows a tail, or extra nipples, or some other clear marker, it's going to be harder with homonid fossils.
I did know a little bit about Mitochondrial DNA from (lay) articles on the Mitochondrial Eve(s) [link] which is just the coolest (at least 'til I start reading about Y-chrom. studies on males). I just didn't grasp the wiki's point at one point, and figured Buffistas would do me better, which you all have. Thanks.