Posted on 02/26/2006 3:25:01 AM PST by Pharmboy
Maybe they just didn't have time to get to know each other.
The question of what Neanderthals and Homo sapiens might have done on cold nights in their caves, if they happened to get together and the fire burned down to embers, has intrigued scientists since the 19th century, when the existence of Neanderthals was discovered.
A correction in the way prehistoric time is measured using radiocarbon dating, described last week in the journal Nature, doesn't answer the enduring question, but it might at least help explain why no DNA evidence of interbreeding has been found: the two species spent less time together than was previously believed.
The old radiocarbon calculation is now known to be off by as much as several thousand years, the new research shows. That means that modern Homo sapiens barged into Europe 46,000 years ago, 3,000 years earlier than once estimated. But the radiocarbon dating under the new calculation also shows that their takeover of the continent was more rapid, their coexistence with the native Neanderthals much briefer.
snip...
Was that advantage cognitive, technological or demographic? Their personal ornaments and cave art, now seen to have emerged much earlier, are strong evidence for an emergence of complex symbolic behavior among the modern newcomers, a marked advance in their intelligence.
That doesn't mean they didn't interbreed with the Neanderthals.
snip...
"Since these two species may have been able to interbreed, as many closely related mammal species can," Dr. Harvati said, "a restricted coexistence interval may be easier to reconcile with the observed lack of Neanderthal genetic contribution to the modern human gene pool and with the paucity of convincing fossil evidence for hybridization."
The caves, it would seem, still hold their secrets.
(Excerpt) Read more at nytimes.com ...
It's worth noting that the geneticist who if I'm not mistaken first tested modern Europeans for Neanderthal mtDNA sequences, Brian Sykes, expected to find them and was very surprised that he did not.
Phil?? Phil Connors?? Now don't say you don't remember me because I sure as heck fire remember you...
Plus the genetic differences appear not to be great enough to guarantee inter-group infertility, even at this chronological remove.
Well, it could be compared to contemporary human DNA, but that would be a waste of time considering the differences between Neanderthal DNA 20,000 years old and modern human DNA would require divergence of our ancestors half a million years ago. Human mitochondrial DNA 20,000 years ago would not be appreciably different from human mitochondrial DNA now.
Mitochondrial DNA is not capable of determining whether populations could interbreed. I trust that you weren't really paying attention when you suggested this? In order to determine capability to interbreed we would need to characterize the full Neanderthal genotype in all its chromosomes. We will never be able to do this. The mitochondrial genome is quite small, being a single loop of DNA containing about 17,000 base pairs. The human genome contains about 3 billion base pairs over multiple chromosomes.
It's Bill Mumy's sister!
Thanks for noticing. You didn't damage anything, did you?
No, but be carefull plowing the cornfield, there's all kinds of stuff out there...
While your field may have nicer equipment and more initials after their surnames, you're still human, extrapolating 'facts' from evidence based upon your prejudices. So, you're no different than the British expeditionists in that regard (the point I was trying to make earlier in the thread).
If we're to believe your field's assertion that a contemporaneous human speciation is proven by tool use, the objects made by tools, and the tools themselves, then it should follow that a native's fertility statue, carved by flint or stone, versus a Frenchy's Boulle etagere, made by planes, saws, chisels, drills, etc., must mean they were made by different species of man.
I suspect your field will eventually get it sorted out. Afterall, the mystery of Piltdown Man was ultimately solved.
Well, I thought it was still debatable, but I will defer to you. Also, there is so much PC-ness in this and related issues, along with agendas that it's hard to dig out the facts and best interpretations.
Obviously your information regarding mtDNA is correct, but I think you have not followed the tone of the threads on this.
The limited data is being used to bolster the position that the differences are great enough to show:
1. no genetic admixture happened
2. no genetic admixture was possible.
Both conclusions appear to me to go way beyond the evidence.
As for the use of contemproary mtDNA, I disagree that the differences would be trivial.
Thanks, blam. GREAT link...
While your field may have nicer equipment and more initials after their surnames, you're still human, extrapolating 'facts' from evidence based upon your prejudices. So, you're no different than the British expeditionists in that regard (the point I was trying to make earlier in the thread).
If we're to believe your field's assertion that a contemporaneous human speciation is proven by tool use, the objects made by tools, and the tools themselves, then it should follow that a native's fertility statue, carved by flint or stone, versus a Frenchy's Boulle etagere, made by planes, saws, chisels, drills, etc., must mean they were made by different species of man.
I suspect your field will eventually get it sorted out. Afterall, the mystery of Piltdown Man was ultimately solved.
Nicer equipment and more initials means little. What we have is 150 years of advances in method and theory! The folks exploring Africa in the early days did not have the type of training we now expect; they were largely wealthy explorers or amateurs funded by wealthy Brits. They did not have the vast amount of data and the organizing theory that we have. Also, there was not a core of trained archaeologists (of a variety of subspecialties) worldwide ready to pounce on the least mistake. These are significant differences.
Your comment on tool use does not apply.
Piltdown again, eh? You realize, of course, that a good many anthropologists didn't trust that find from the beginning? By about 1932, Friedrichs and Weidenreich had both published research suggesting the lower jaws and molars were that of an orang--and they were correct. Piltdown was pretty much dead after the South African finds beginning in 1924.
No, Piltdown is not a good example. If you really want to see mistakes that never get corrected, try some of the creationist websites.
As for the use of contemproary mtDNA, I disagree that the differences would be trivial.
Upon what basis?
THAT'S funny...and she looks like she's about to say "mooghla?" which means "why not?"
Yer DNA would confuse the crap out of them "perffessers"!
Why?
I'm not trying to be argumentative here, but set me straight.
Prior to DNA analysis, your field pretty much based its theories about early humans on age of the remains, skeletal structure, and tool design/use. Tools were/are given much weight in your field when differentiating species.
If a group of humans 50,000 years ago ran after their prey hunting it with spears and another group gathered it by hand (say, living near a stream during salmon spawning), how can one theorize a different species from the tools and techniques each group used to gather food?
I realize there's more to the theories of human speciation than just tools, but this is the point that piques my interest the most in archaeology.
You'll probably tell me it's the totality of the evidence, but I'm not willing to allow tools as evidence here since even today it's difficult to qualify cultural superiority through tool use.
Well, since you seem serious I'll see what I can do.
You are right that tools have been used in the past as one of the main factors, but that is becoming less and less the case as better fossils are found. These tools have the advantage of being made of stone, so they last a long time. And sometimes they are quite numerous.
But with the advent of several forms of radiometric dating and all of the nice fossils from eastern Africa, stone tools became much less important for species determination (although important for their role as tools).
Also playing a role as more information come to light are the cultural sites; the refuse (bones, etc.) tell a lot about diet and hunting activities.
A good website that tells a lot about tool use in relation to hunting and food production is here: Link.
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