Even though we've found widespread Neanderthal and Denisovan introgression in all modern non-subsaharan humans, and sub-saharan Africans have been found to have introgression from a third archaic hominid... people keep coming up with reasons why Neanderthals went extinct. Recently the one about dog domestication being mankind's trump card over Neanderthals has been revived again:
Newsflash: Neanderthals did not go extinct, and neither did Denisovans. We are all hybrids of "archaic homo sapien," it's direct descendent "homo sapien sapient" and at least 3 other archaic populations. It's probably more like 6 archaic populations, since the Denisova hominid is hybrid of eastern Neanderthal, another line that split off from the neanderthal/human line a million years ago, and yet another line that split off as much as 3 million years ago. Plus 90% of people outside of sub-Saharan Africa have assimilated a microcephalin gene from still another mysterious hominid that split off from our line 1.7 million years ago or more.
I assume the reason that this hasn't hit home with scientists who still want to explain the demise of neanderthal in a species vs. species manner is that only 4% to 10% of our nuclear DNA is at present contributed to these other hominids. One has to wonder where they think the other 90% comes from.
You see, nuclear DNA is not the same as mtDNA or yDNA in that it is not so finite. In other words, just because a person has 90% homo sapien sapient nuclear DNA doesn't mean that it all came from descendents of mito Eve or Y-Chromosome Adam.
Furthermore, mito Eve and Y Adam were not anatomically modern humans. True anatomically modern humans don't show up until around 115,000 years ago in Africa and the Levant, and both of our proposed progenitors are far older than that. Previous to the first anatomically moderns in the fossil record, we had "almost modern" homo sapiens from North, South and East Africa all the way to South China and mito Eve and Y Adam most likely came from separate tribes anywhere within that zone. They may have been on separate continents for all we know for 100% certain. In fact the first undisputably modern HSS was found in Australia and is dated to 50 thousand years ago, but he is not our ancestor: his DNA split off after Neanderthal but before mito Eve or Y Adam.
This specimen, Mungo Man, is more gracile than the anatomically modern humans that came directly after him all over the world. The European version of anatomically modern human from that era, once dubbed "cro-magnon," is much more robust and many of the specimens have neanderthal derived features. Even in Australia, the successors of Mungo Man are more robust and archaic than that 50,000 year old skeleton was. Mungo Man may have been the descendent of a far ranging, endurance running type of HSS because he stood about 6'6 and had such a lithe bone structure.
A piece of Mungo Man's DNA has imbedded itself in a chromosome of some people living today, so although we know that he didn't contribute to our mtDNA or yDNA lines, we are sure that at least one person in his genome was one of our ancestor's paternal grandmas or maternal grandpas. This population of anatomically modern human passed on its nuclear DNA to us as well as the freakish strand in our chromosome, but because it was not the direct maternal or paternal line to any modern humans it does not show up in mtDNA or y Chromosome studies.
If the freakish accident that caused it to embedd something into out cromosome hadn't happened, we wouldn't have even known that it ever mated with us. Evidence of Mungo Man does not show up in our nuclear DNA because his nuclear DNA is pretty much the same as ours. We have no way to discern whether our nuclear makeup comes from y-DNA Adam, Mito Eve, Mungo Man, or any of the other ghost populations of anatomically modern human and near-anatomically modern human. Most likely our nuclear DNA came from all of them, not just Adam and Eve.
What's more, some researchers have found that the MAJORITY of our immune system was inherited from archaic hominids, not HSS.
So if you're only 8% Neanderthal and 2% Denisovan. that doesn't mean that you're 90% human the way we think of human today.
It's more like 8% Neanderthal, 2% Denisovan, 12% African archaic, 8% Levantine archaic, 5% Indian archaic, 5% Indonesian Archaic, 10% Central Asian Archaic, 10% Mungo Man, 10% extinct y Haplogroup F*, 10% cro-magnon, 10% extinct mtDNA M*, and maybe even 10% late surviving Rhodesian Man, late surviving Idaltu Man, or even Red Deer Cave People (if you believe they're modern humans early OOA like some scientists want you to to).
Plus we have a microcephalin gene from a homo erectus soloensis descendent or a 3 foot furry hobbit.
Incidentally, some of these ancient hominids whose nuclear DNA would be virtually indistinguishable from ours were a lot different looking from us than Shanidar Neanderthal was. Some Neanderthals had chins, and some of our "anatomically modern" ancestors didn't, for instance. Some of their skulls are at least as divergent from ours as neanderthals was, and it is more due to their skeleton that they are placed within our ancestral line.
So what am I getting at?
Neanderthal may have contributed as much to your personal genomic make-up as any other of your ancestral ice age populations. Some of your ancestors of about the same era were probably even uglier and alien-looking than your Neanderthal great grand-uncle was.
Also, "pure" homo sapien sapient is extinct: there was 100,000 years of human lineages splitting off from our line between the departure of Neanderthal Man and the birth of Mito Eve and yDNA Adam. Those millions of lineages created millions of populations and most of them have left no modern direct descendents, just like Neanderthal...and though their mtdna and y haplogroups don't survive, they're contributions to our modern genomic make-up are hidden in our nuclear DNA, immune systems, chromosomes. etc.
Since every instance of the mtDNA and Y lineages that survive contain archaic introgression, isn't it obvious that we are all hybrids and that "pure" homo sapien sapient suffered the same fate as "pure" Neanderthal?
Joe Lyon Layden is a prehistoric fiction author and primitive musician. To receive a free copy of this entire novella "The Man from Parkho Khatune Bears Favor," as well as three free songs and monthly updates, freebies, and discounts on Joe's ongoing work, please sign up for the newsletter below.