IMG Source - Ancient-Origins.net
In 2009 Ian Tattersall published Human origins: Out of Africa wherein he argued passionately that humanity evolved in Africa and only recently spread across the world.
"Our species, Homo sapiens, is highly autapomorphic (uniquely derived) among hominids in the structure of its skull and postcranial skeleton. It is also sharply distinguished from other organisms by its unique symbolic mode of cognition. The fossil and archaeological records combine to show fairly clearly that our physical and cognitive attributes both first appeared in Africa, but at different times. Essentially modern bony conformation was established in that continent by the 200–150 Ka range (a dating in good agreement with dates for the origin of H. sapiens derived from modern molecular diversity). The event concerned was apparently short-term because it is essentially unanticipated in the fossil record. In contrast, the first convincing stirrings of symbolic behavior are not currently detectable until (possibly well) after 100 Ka. The radical reorganization of gene expression that underwrote the distinctive physical appearance of H. sapiens was probably also responsible for the neural substrate that permits symbolic cognition. This exaptively acquired potential lay unexploited until it was “discovered” via a cultural stimulus, plausibly the invention of language. Modern humans appear to have definitively exited Africa to populate the rest of the globe only after both their physical and cognitive peculiarities had been acquired within that continent."
In just more than a decade since he wrote those words, ~half a dozen human species have been discovered and good, high coverage genomes have been produced for two of them. It has been discovered as a result that almost all people alive today are hybrids with one or more extinct hominins. In Europe and Asia, we are hybridized with H. neanderthalensis. In E. Asia , Australia, Oceania, and the Americas, we are hybridized with H. denisova. In Africa some people are hybridized with another hominin, perhaps H. erectus or H. ergaster, something old enough we cannot yet extract DNA from fossils.
As a result of the incredible discoveries we have made in these last few years, every single statement Tattersall confidently made in the above opening excerpt from the Abstract to that seminal paper is proved false.
H. sapiens is not particularly autamorphic, with ~2 dozen closely related species of similar morphology. Neither is our cognition any more singular, as at least two other species of our genus are now shown to have produced striking art, had tailored clothing more than 50kya, and certainly showed similar aptitude in making tools, hunting, and ability to spread into novel habitats. The earliest date for modern humans has more than doubled and is no longer found in Africa, but the Levant. The first hominin did not arise in Africa at all, but in the Balkans. Graecopithecus freybergi arose ~7mya and careful examination of it's teeth reveal features that are only found in Homo. That conformation was not sudden and unprecedented but clearly derived from essentially constant hybridization with our hominin cousins. Symbolic behaviour is perhaps the least changed of his assertions, but beads ~160kya show it began much earlier than he claims, and the fact several hominins undertook it makes his assumptions about language moot. Finally, modern humans did not develop any of those traits and features alone, nor only in Africa, but have participated in such developments that were undertaken across the entire range of hominins by Sapiens, Neanderthals, and Denisovans, at least.
Neanderthals seem to have disappeared by ~40kya, Erectus by ~25kya, and Denisovans no later than ~15kya. Given that no less than 40% of the Neanderthal genome is extant today in modern populations, it is clear that species didn't die out, so much as it was simply incorporated into the hybrid hominin population. It would be hard to argue with any evidentiary basis that the same didn't happen with Erectus and Denisova as well.
We appear not to be a species, but to be instead a heterotic population of hybrids, derived from at least four closely related species. This should knock the wind out of the sails of racists, if nothing else. The only racial purity potential to any living people might be relic in Africa, but given our hypersexuality and obvious exogamy, that appears to be extremely unlikely. The rest of us are hybrids.
Since the last half million years or so when modern humans first arose in the Levant, we've participated with our fellow hominins in a roving love fest roughly centered in the Pontic Steppe between the Black Sea and the Caspian, where three of the four species are all known to have been present from time to time. Perhaps the hypersexuality of Sapiens catalyzed the subsumation of our variety into one hybrid population, but it seems the others did not wait on us to show up, and started early interbreeding with each other several times before we made our debut.
Anyway, I have been fascinated researching our prehistory recently and thought I'd share some of what I've learned in the past week for those who might be interested.
Highest Denisovan DNA in Philippine Negritos
Microscopic Examination of Denisova Cave
Amazing Sculpture, Jewelry, Bone Needles from Denisova
This should get you started on the journey I have been on in the last week that shook the foundations of what I believed about humanity. One thing that has become clear to me is that humanity is not come out of Africa, or Europe, Asia, or anywhere but Earth. I hope you are as excited by these discoveries as I have been.