(If this is already in play in another thread, apologies, and this OP can be killed.)
In the NYTimes coverage of the discovery (can’t find the cite), they went a little bit into the genetic markers that are passed down enabling the entire line of research into “percentages” of different hominid genetic material. (Is “hominid” the correct word?) And I think I remember a comment that the signs of interbreeding increased the farther the geographic spread of the population from the putative H. sapiens geographic origins.
Is this simply a confirmation of the speciation concept of environmental separation being paramount? There’s a word for that, too: what is it?
(:rolleyes: at myself) (Ancient bog-fermentation bubbles from my kind since I read about speciation now being released…)
As far as we know Homo sapiens developed in Africa. It may well be that even by this time Neanderthals were no longer present in Africa so interbreeding didn’t occur until some Homo sapiens migrated out of that continent. This would also explain why signs of interbreeding are higher further from the center of origin. Those signs come from migrations back in.
I’m not sure exactly what you’re referring to, but modern humans (Homo sapiens) didn’t interbreed with Neanderthals until they had left Africa. (They couldn’t have interbred with them in Africa since Neanderthals evolved in Eurasia.) Therefore only populations outside of Africa show these Neanderthal genes (with the exception of some limited occurrence due to back migration of sapiens into parts of Africa).
Later on, sapiens encountered the Denisovans, who were related to the Neanderthals, probably somewhere in Asia, and interbred with them. This resulted in Melanesians and Australian aborigines having both Neanderthal and Denisovan genetic material. Therefore the sapiens populations farthest from Africa in the Old World show an indication of having interbred with two separate other human lineages.
Not really. The most common model of speciation is allopatric speciation, in which populations isolated by geographic barriers gradually become genetically distinct and eventually different species. That was probably responsible for the genetic differences that developed between sapiens, Neanderthals, and Denisovans. However, it does not account for the fact that Australasian sapiens have the most genetic material from those populations. In fact, the greatest divergence between sapiens populations is found within Africa, where the oldest lineages, the Khoisan and pygmies, still persist.
Not 100% sure what you’re really asking here, but I’ll make a guess.
The Christian Science Monitor article is about fossils from some 400,000 years ago. That was about 300,000 years before modern humans expanded from Africa. So there wouldn’t be any chance of interbreeding between Neandertals and humans at that point.
Yes, scientists recently were able to extract DNA from fossils from a famous site in Spain called *Sima de los Huesos *(Pit of Bones). This is a treasure trove of fossils predating the emergence of Neanderthals by at least 100K years. The mtDNA confirmed that these folks were the progenitors of the Neanderthals. But this was all long before we got to Europe (only ~40K years ago).
I think I saw some female Denisovans on an episode of Star Trek TOS. They were pretty hot. It would seem that some male H. sapiens would have wanted to “mix” with the female Denisovans they ran into.
Even if we’re taking seriously the premise that male H. sapiens in general wouldn’t have found female Neanderthals and/or Denisovans attractive, of course that doesn’t rule out interbreeding. All you need is for male Neanderthals and/or Denisovans to find female H. sapiens attractive, and vice versa.
Genetic mixing is not produced solely by “us” wanting “their” women. It works the other way around too.
Also, the Paleolithic wasn’t like a singles bar in NYC. I would assume that, at least part of the time, you took the mate who was available at the time.
Actually, Neanderthal mitochondrial DNA, which is inherited entirely through the maternal line, has not been found in modern humans. This implies that the admixture found in the nuclear DNA of modern sapiens populations was the result of male Neanderthals mating with female sapiens (although other scenarios are possible).
So it seems that Nick Neanderthal liked Homo Sapien women and was a touch rapey? Or its just a coincidence that descendants of Nicola Neanderthal and a modern Human do not survive to this day>
Similarly Neanderthal Y-chromosome, inherited paternally, has not been found in modern humans either. Even though Neanderthal Y-chromosome has not been tested(?) we know this because all Y-chromosomes found outside Africa can be connected to a common African ancestor who lived less than 100,000 years ago.
Thus all purely agnatic Neanderthal lines and all purely uterine Neanderthal lines died out (at least among humans tested to date) but that doesn’t imply non-Y Neanderthal nuclear genes died out.
Have they concluded for sure that Neanderthal isn’t a Homo sapiens subspecies?
I mean, we are pretty sure Cro-magnon and Neanderthal interbred, and cross-species interbreeding (that results in fertile offspring) is rather rare.
From reading recent literature, it’s interesting as they seem more and more convinced Neanderthal is a species while also more and more convinced we interbred.
Because the time period of interbreeding was rather brief, compared to the overall time of existence of both species, I think the tendency is to keep them as separate species. But it’s largely an academic argument, since it concerns populations that no longer exist.
As I said in another thread, it depends on your definition of species and subspecies.
According to the Biological Species Concept, two forms are separate species if there is only limited interbreeding in nature.
Neanderthals and sapiens certainly hybridized, but that hybridization appears to have been very limited in space and time. It was only in the Middle East (probably) not long after sapiens left Africa. It did not take place generally over the entire range of overlap of the two forms.
Based on modern interpretation of the Biological Species Concept, this would make the two forms separate species. (Wolves and coyotes are fully interfertile and hybridize, but are regarded as separate species because they retain a separate identity where they overlap).
Some scientist may differ in their interpretation, and regard that the degree of hybridization means the two forms were subspecies within the same species.