She's a little older now, but still acceptable as far as I'm concerned.
http://img.photobucket.com/albums/v421/Jajoba/RaquelWelch.jpg
By the way, in regard to using a time machine for scientific research, see my post number 87.
Posted on 02/26/2006 3:25:01 AM PST by Pharmboy
Thanks
Can't find a link for it right now, but one theory I've seen is that the Caucasus Mountains and an Ice Age might have caused the isolation of the gene pools in the first place. Recall that high but normally passable mountains separate the Black Sea on the West and the Caspian to the east. It's a long way around the water barriers if for some reason you can't get over the mountains.
In this scenario, humanity expands north across the Caucasus only to have a population isolated there as Ice Age conditions close the passes. That's the birth of the cold-adapted Neanderthals.
It may be too specific for the available data.
Hmmm...if that's what female neanders looked like, build me a time machine.
I am not a paleontologist, and I hate to disagree with one, so I will let other paleontologists do so instead. In post #211 I linked three relevant journal articles. One of these goes directly to what I suspect your teacher alluded to:
The Neanderthal taxonomic position: models of intra- and inter-specific craniofacial variationThe morphological distances between Neanderthals and modern humans, and between Neanderthals and Late Paleolithic/early anatomically modern specimens, are consistently greater than the distances among recent human populations, and greater than the distances between the two chimpanzee species. Furthermore, no strong morphological similarities were found between Neanderthals and Late Paleolithic Europeans. This study does not find evidence for Neanderthal contribution to the evolution of modern Europeans. Results are consistent with the recognition of Neanderthals as a distinct species. [bold print added]
The second, although I don't think it's precisely what your teacher had in mind, is a difference between modern humans and Neanderthals that is without question greater than the difference between any two modern humans: Surprisingly rapid growth in Neanderthals. What this study finds is that Neanderthals reached full maturity (adulthood) by about age 15. No modern human reaches full maturity by age 15.
Finally, there is the implicit distinction of the FOXP2 allele that exercises a crucial function in human speech and language. This mutation is dated to hundreds of thousands of years after mtDNA dates the last common ancestor between Neanderthals and modern humans. Every modern human relies on this mutation to speak properly; it is implicit that this mutation was absent among Neanderthals.
But, as has been noted over and over, there is sharp disagreement in paleoanthropology circles about all of this.
I do find that article rather interesting. I had actually skimmed it once before, but this is the first that I read it.
First, I would very much agree with you that the portrait of Levantine human evolution and also specifically of the relationship between HN and HS in the Levant is much more complicated than that in Europe.
Second, I would reiterate that I don't outright reject the multiregional hypothesis. I do think it has a whole lot of work yet to be done if it is to prevail, but in truth I am agnostic in that regard.
Third, and to be more precise, I do not reject posited admixtures of Homo sapiens and other hominids in either the Levant or in Southeast Asia during the 120,000 B.P. to 85,000 B.P. timeframe; nor do I reject posited multilocus emergence of modern human populations in a zone stretching from East Africa to Southeast Asia. In both case, I am 'agnostic' at this time.
Fourth, and where I think some confusion arises, based on the totality of the evidence to date, and overwhelmingly so, I do reject at this time posited admixture of HS and HN in Europe in the 45,000-30,000 B.P. timeframe.
Speaking more generally, I personally think that at certain points this article appears to flirt with Lamarckism, but I will attribute that to the writing style of the author rather than any of the underlying cited research.
Moreover, I'd be curious to have this placed in a more modern context. Not that 2002 is very long ago at all! But there have been a lot of significant discoveries in just the past 5-6 years and I wonder to what degree they are incorporated here.
But, in short, to reiterate, I do agree that the portrait in the Levant is more complex and more inconclusive. I will also admit that I am less well-versed in areas of hominid evolution other than the Neanderthal/Cro Magnon era in Europe. The latter has sparked my interest more and so I've looked into it in more detail.
And a question you might be able to help out with: Isn't the most recent view that Europeans originated from humans that travelled somewhere over to South or Southeast Asia and then came back over to the Levant and Europe? I might be mistaken in this regard, but that seems to be my vague recollection. I'm gonna have to look that up if you can't help out!
If you're talking about the discussion of environmental influences on the knobbiness of bones, etc., that's not really Lamarckism. The author is not arguing that such differences, if acquired by repetitive stresses, are passed to offspring, nor is he citing people who do. But I don't think the idea has much merit. The discussion of of the emergence of specific Neanderthal differences in very young specimens undercuts it.
Some have pointed out the Dmanisi, Georgia fossils as evidence for a back-to-Africa migration of erectus types. I suspect that was enough earlier to be irrelevant to the S-N split.
She's a little older now, but still acceptable as far as I'm concerned.
By the way, in regard to using a time machine for scientific research, see my post number 87.
Well, the work she's had done certainly agrees with her...
Sorry, I missed this question earlier. I won't have a chance now to comment on this until late tonight or tomorrow morning. But I'll get back to it.
PS. I'm not altogether well-versed on this particular question, but I'll give it my best shot!
Yes, I read over those sections again and you're right that Lamarckism isn't the best description for what I was getting at (which is what you inferred). And I also concur that the line of reasoning has little merit, not only due to the emergence of Neanderthal features in very young specimens, but also due to the failure of non-Neanderthal populations in the exact same environments to develop equivalent features.
Thanks. I'll see what I can find also. And I do appreciate your help.
Arguments from morphology alone are as silly as phrenology, and would lead to hundreds of ridiculous inferences if applied to modern humans. Arguments from absence are only as strong as the evidence suggests exhaustiveness, and here is does not remotely do so. N. sites have been found at recent as 30,000 years ago (subject to some error in the dating, to be sure - maybe 35ky bp really), some in regions long since passed by H. settlement (e.g. in the Balkans). As for the idea that N. couldn't talk, it is extremely implausible on its face. There are no significant anatomical differences detectable in anything connected to speech.
Moreover, the supposedly so rapid spread of H. through the range of N. is a time scale of 7,000 years. 7000 years ago, a few farmers had evolved villages in the fertile crescent, and not a single human grouping on the globe today existed. In other words, 7000 years in the tiny cockpit of Europe is forever, for all purposes of ordinary history and diffusion of peoples. It is rather like saying the Germans displaced the Babylonians, and there is no evidence they interbred. Except the time scale is twice as long. There is no reason to expect a subset of mankind to last 7000 years unaltered in the first place.
As far as I know, "Lucy" was australopithicus..
While an ancestor of modern humans, she was not what I would consider "human".. by any stretch of the imagination..
I don't see any reason that Homo sapiens would want to go on a romp with Neanderthal any more than he'd want to do it with Bonobo apes.
It is worth noting, BTW, that I personally question whether the "Neanderthal" population in the Levant was of a genetic continuum with the "Neanderthal" population in Europe. But, regardless, my personal doubt in that regard is not the prevailing view at this time.
OK, lemme see if I can explain this properly. If someone identifies any errors then they are welcome to correct me.
The prevailing view is that Homo erectus emerged in Africa roughly 2 million years ago. Then, Homo erectus was the first hominid known to have dispersed out of Africa into the Levant and Southeast Asia, roughly 1.8 million years ago. That's the easy part, then things get dicey.
Although not universally accepted, the prevailing view now is that Homo erectus in Africa evolved into Homo antecessor by roughly 900,000 years ago, and that this was the last common ancestor of Neanderthals and modern humans. By roughly 800,000 years ago, Homo antecessor spread into southwestern Europe (i.e., Spain).
By around 500,000 years ago this population then evolved into Homo heidelbergensis (who was previously thought the last common ancestor of Neanderthals and humans, before the discovered of H. antecessor). There's some dispute about the proper classification of H. heidelbergensis. Many paleoanthropologists regard H. heidelbergensis as an intermediate "chronospecies" - that is, a species that has altered so much over the passage of time that if members of the species had lived at the same time as members of the same species hundreds of thousands of years beforehand they would be regarded as different species, although technically they are the same species. (This might be confusing. If you want, I can try to explain the concept a bit more.)
In any event, by about 200,000 years ago H. heidelbergensis had evolved into H. neanderthalensis. The Neanderthals then spread throughout Europe from west to east, and later into the Levant, when an Ice Age pushed the H. sapiens out of the Levant back into Africa. So the arrow of speciation is as follows:
Homo erectus -> Homo antecessor-> Homo heidelbergensis -> Homo neanderthalensis.
Meanwhile, back in Africa, Homo antecessor continued evolving until early Homo sapiens emerged as two subspecies roughly 200,000 years ago. There is some controversy as to the correct relationship between H. sapiens and a set of fossils previously known as Homo rhodesiensis, now thought to date roughly 300,000 years ago. Some paleoarchaeologists regard this as an intermediate species, others as a chronospecies perhaps in continuity with H. heidelbergensis (this was the pre-H. antecessor view), and others as an archaic Homo sapiens.
In any event, one of the known H. sapiens subspecies went extinct around 150,000 years ago and the other became us. According to mtDNA studies, the most recent common ancestor of all humans alive today lived in Africa 171,500 years ago (give or take a bit). The currently prevailing view is that this Anatomically Modern Homo Sapiens (AMHS) migrated out of Africa roughly 100,000 years ago and replaced other hominid populations throughout Asia and Europe.
So, the arrow of speciation of AMHS modern humans would be:
Homo erectus -> Homo antecessor-> "Archaic" Homo sapiens (arguably Homo rhodesiensis or Homo heidelbergensis) -> Homo sapiens sapiens
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.