I’ve read a number of articles today about the new paleontological findings in Asia and Australia and what they mean for theories of the origin of the human species. I have a few observations.
First, we have a very great need for a new, rigorous definition of “species”. The conventional definition of species is that members of the same species may interbreed and produce fertile offspring.
Using that definition the statement that modern humans (Homo sapiens sapiens) have some percentage of Neanderthal or Denisovan DNA is gibberish unless Neanderthals and Denisovans aren’t different species from ours at all but members of different subspecies of the same species. In other words Homo sapiens neanderthalensis not Homo neanderthalensis.
This stuff is all pretty controversial because of its bad history. Its discussion was first broached more than a century ago by a bunch of German racists desperate to prove the primacy of white Europeans. I don’t believe that at all but it makes just touching on the subject hard.
The most recent results have cast some doubt on the notion that modern humans originated in sub-Saharan Africa. The problem: the oldest fossil remains of modern humans aren’t from sub-Saharan Africa at all but from Morocco.
My opinion for more than 50 years has been that
- Our genus Homo originated in sub-Saharan Africa.
- Its possible that there are no species other than ours in the genus.
- Neanderthal, erectus (Peking Man, Java Man), and other variants are all members of the same species as we are.
- Our species is a lot older than has been thought.
- While it might have originated in sub-Saharan Africa, Asia is actually just as good a candidate.
so I’m pretty gratified with the recent findings since they tend to confirm what I’ve been saying all along.
Now if only some evidence confirming my views on language families is found…
Speaking of neanderthals, I don’t know if you’ve seen this population genomics study that identifies what appear to be the pre-Norman Kingdoms of Ulster, Leinster, Munster and Connacht:
https://www.biorxiv.org/content/early/2017/12/08/230797
There hasn’t been as much work on Ireland as compared to the rest of the Islands. The report indicate higher Viking presence than previously believed (whatever that means, because I understood Vikings were not simply raiders, but settlers and nation-builders).
It depends what you mean by originate. Fully modern anatomically humans did originate in sub-Saharan Africa some 200,000 to 300,000 years ago. Behaviorally modern humans are much more recent, but also originate in sub-Saharan Africa. All bets are off as you go back a few million years. Many of the fossils are plainly African, but there are many fossils from Eurasia that might line on the family line.
Biology has changed a lot since I went to school, but wasn’t “species†always a bit of a flexible term? I.e., for populations A, B, and C you might find that A and B can interpreted successfully, B and C can interbreed successfully, but A and C could not. A and C are different species according to the interbreeding rule, but what about B?
With 2% Neanderthal DNA in Europeans, rather than 25%, I think we have to conclude that Neadrathals and Sapiens were almost distinct species. There are lots of reasons populations might not mix, but unless Sapiens had an amazingly successful eugenics campaign, I think a biological reason is most likely.
Actually, that’s something I suspect is the case, too. I suspect that there’s a deep-seated problem with the different.
Gustopher:
I’ve sometimes read that the average Neanderthal population in Europe was on the order of 10,000 people. So it’s not implausible that over a few thousand years populations of say 50-100,00 Cro Magnons might have obliterated them genetically.
As for Just How the Neanderthals failed … My guess, anyhow … Come winter time, from observation last century of hunter gathers, they tend to break up into individual or small family groupings. Suppose such groups back in ice Age days had three or four persons in them — Mom, Dad, a kid or two, Uncle Harvey. Cro Magnons weighed less on average than Neanderthals and likely got by on smaller quantities of meat and vegetation, so we might suppose Cro Magnon groups of the same size would find it easier to survive a hard winter. Or alternatively that Cro Magnon groups might have been one or two people larger, allowing for more hunters, or maybe more care for individuals hurt during hunting, etc.
I.e., being somewhat smaller gave modern Homo Sapiens an edge over Neanderthals during periods when food was shsort — which describes most of an Ice Age.