>somehow Neanderthals managed to survive across most of Eurasia for nearly 400,000 years, longer than modern humans have been on Earth.
These narrative simplifications end up just being confusing.
Neanderthals from 400kya are often classed as Heidelbergensis. These guys were less Neanderthal-ish and more similar to us... being closer to and less divergent from the sapiens-neanderthal LCA. Neanderthal-Denisovan divergence occurs at this time.. so calling them Neanderthals rather than Neanderthal ancestors is kind of messy.
There is a shortage of fossil evidence from this and earlier periods... It's called the "muddle in the middle."
In any case.... Sapiens also had ancestors at this time. We don't have fossils, but something has to be our ancestors. So if we are calling Neanderthal ancestors from this period Neanderthals... it would be more consistent to call sapien ancestors sapiens.
Individual populations may have been insular, small and most died out. But... there were people everywhere.
Humans existed over a vast range. From south Africa to Northern Eurasia. East to west. At this point in time... I think it's confusing to think of neanderthal/denisovan/sapiens as different species.
Individuals may have been inbred... but the overall genetic diversity across the whole range was greater than the genetic diversity we have today. In some sense, we are the inbred ones.
Also... population estimates are pretty dicey. We don't really know. Could have been booms and busts. Could have been ideal habitats with higher populations.
We still have a fairly poor grasp of human "natural history"
> Neanderthals from 400kya are often classed as Heidelbergensis.
Heidelbergensis is the last common anscestor of Neanderthals, Denisovans and us.
We were all around for just as long, 400kya+, and before that, it was Homo Erectus.
All of them, Erectus, Heidelbergensis, Neanderthals, Denisovans and Sapiens were walking around at the same time. There's plenty of fossil records we've uncovered that show that to be true.
It was only in the last 100k years or so that we remained and the other variants "died out".
Heidlebergensis is no longer thought to be on the sapiens lineage. It's probably the ancestor of neanderthals and denisovans. 400kya is around the time of this divergence, based on recent genomics. They were the same species at this time.
The Sapiens lineage is now thought to have diverged significantly earlier.
Erectus existed, but in pockets.
Other lineages existed also. At the very least, Homo naledi. Probably other dwarf lineages, an African "ghost lineage" and probably others.
Neanderthals and denisovans are structured... With subspecies, hybrid zones and whatnot.
There are also many sapiens lineages with no descendants. Most of them.
We shouldn't use the word "species" lightly with hominins. There's no accepted way to properly classify archaic humans.
For example, some paleoanthropologists classify most archaic humans as h. sapiens. Anatomically modern humans become h. s. sapiens, neanderthal become h. s. neanderthalensis. This incorporates the middle pleistocene hominins from mainland Asia pretty well to boot. Many of those same people also use the "conventional" binomial terminology when they're not making a very specific point, so you can't just look at usages to understand where they're coming from.
There's also a hundred other classifications, some giving neanderthals their own species, others including it with heidelbergensis, and so on. None of them has clearly "won" and probably won't while we keep publishing "new" transitional forms every couple of years.
Sure... and it would help if there was more consistency in general.
But given that there isn't, we should at least maintain internal consistency. That's what I was commenting on above. You can't use one conceptual framework for Neanderthals/Eurasia and another for Sapiens/Africa. It's confusing... and you end up with statements that are essentially false.
Neanderthal and Sapiens exist approximately concurrently. The "classic neanderthal" form doesn't predate sapiens. It only predates Sapiens if we define "Neanderthal" from the point of divergence. If we do that, we need to define Sapiens the same way. It can't be the establishment of a founder population for one and the emergence of a distinct form for the other.
I'm not advocating for one system or another... or even for the establishment of one consistent system necessarily.
Did they really die out, or did the population just merge with modern humans? Most people on the planet have some Neanderthal DNA, so clearly there was some intermixing. If modern humans were a much larger population, it makes sense that the Neanderthals only contributed a small amount of DNA to the gene pool. I could imagine that they were just slowly absorbed into the much larger Sapiens population.
Virtually every population outside of Sub-Saharan Africa has Neanderthal and Denisovan DNA between 1-4%. This includes all of Eurasia, all pre-Columbian American populations, Aboriginal Australians, Papuans, etc.
Is there any research about why Sub-Saharan Africa doesn't have Neanderthal DNA?
Is the argument that the tribe of humans from Africa was good at repelling outside invaders, but themselves expanded outwards and assimilated (and then outnumbered) the other populations, or something else?
It just seems a bit bizarre given that all humans elsewhere have relatively similar amounts (but quite a low amount) of Neanderthal DNA, which seems to suggest a reasonable amount of migration, interaction and interbreeding between populations everywhere except Africa.
There were multiple waves out of Africa but Most early anatomical human groups never left Africa as a result, there’s more DNA diversity within the continent than outside Africa
Its confusing because the non-african group grew exponentially while the intra-African continent continued to mature
The anatomically modern humans that left Africa spread rapidly and aggressively across the world basically absorbing and destroying every proto-human group and ecological niche and
now the world is ruled by the aggressive narcissistic chimeral hybrid of human (African) Neanderthal (European proto human) and denisovian (Peking man) that survived the exit snd expansion
It also doesn't hold for the African Diaspora, especially in the Americas (and probably flowing back into Africa as we speak). It's also worth considering that many of the actual traits that Neanderthal-associated genes codes for probably have analogues in the much-wider African genome.
The version of the claim I believed is that Sub-Saharan Africans (especially as of ~2000 years ago) basically don't have any Neanderthal DNA.
Your follow-up doesn't appear to contradict that (of course this wouldn't hold when populations start mixing in modern times and wouldn't have ever held 100%) so I was confused.
However the article does in fact dispute my previous belief:
>The researchers found that African individuals on average had significantly more Neanderthal DNA than previously thought—about 17 megabases (Mb) worth, or 0.3% of their genome.
This is as opposed to 1-4% of genomes for populations outside of Sub-Saharan Africa.
>They also found signs that a handful of Neanderthal genes may have been selected for after they entered Africans' genomes, including genes that boost immune function and protect against ultraviolet radiation.
>The best fit model for where Africans got all this Neanderthal DNA suggests about half of it came when Europeans—who had Neanderthal DNA from previous matings—migrated back to Africa in the past 20,000 years.
"The past 20,000 years" is pretty broad and seemingly includes modern era exchanges, but AFAIK that can't account for selecting Neanderthal genes or for how widespread Neanderthal DNA already is.
True, but I'm guessing they're referring to anatomically modern humans which have only been here for a couple hundred thousand years. Not sure that's a meaningful way to look at it since I'm assume Neanderthals also evolved somewhat during that time.
One thing that confused me in TFA is that it says that "[neanderthals were] maybe a couple of thousand breeding individuals", yet they were enough to inter-breed with sapiens at some point(s) [1]. In my mind, tribes of "far-flung populations of just a few dozen individuals" would be shy and difficult to find.
These narrative simplifications end up just being confusing.
Neanderthals from 400kya are often classed as Heidelbergensis. These guys were less Neanderthal-ish and more similar to us... being closer to and less divergent from the sapiens-neanderthal LCA. Neanderthal-Denisovan divergence occurs at this time.. so calling them Neanderthals rather than Neanderthal ancestors is kind of messy.
There is a shortage of fossil evidence from this and earlier periods... It's called the "muddle in the middle."
In any case.... Sapiens also had ancestors at this time. We don't have fossils, but something has to be our ancestors. So if we are calling Neanderthal ancestors from this period Neanderthals... it would be more consistent to call sapien ancestors sapiens.
Individual populations may have been insular, small and most died out. But... there were people everywhere.
Humans existed over a vast range. From south Africa to Northern Eurasia. East to west. At this point in time... I think it's confusing to think of neanderthal/denisovan/sapiens as different species.
Individuals may have been inbred... but the overall genetic diversity across the whole range was greater than the genetic diversity we have today. In some sense, we are the inbred ones.
Also... population estimates are pretty dicey. We don't really know. Could have been booms and busts. Could have been ideal habitats with higher populations.
We still have a fairly poor grasp of human "natural history"