Cause that first title would have not made me click the story.
Across the animal kingdom, single-species genera are somewhat uncommon. Why is there only one species of the genus Homo?
A related question. The extinction of the last surviving non-Sapiens coincides more or less with the retreat of the last glaciation period and the emergence of human civilization (see the chart midway into the linked article). These events also seem to have happened about the same time as the extinction of certain large land mammals such as the saber-tooth tiger and woolly mammoth.
Are these extinctions, large land mammals and species of Homo, connected in some way with the retreat of glaciers and/or the emergence of human civilization?
These questions are asked (but not really answered) in the first part of the book Sapiens.
It's not lost on me what happened to Native Americans in North America when Europeans showed up. Disease, competition for resources, social disruption and war drove entire tribal groups to extinction. And Native Americans are Homo-sapiens not some random archaic Hominid.
https://jaymans.files.wordpress.com/2014/05/global-genetic-d...
There are also various degrees of admixture from other human species (Neanderthals, Denisovans, something similar to H. naledii) in different human populations which also contributes to our genetic diversity.
https://upload.wikimedia.org/wikipedia/commons/thumb/b/b8/Ho...
Some argue that these factors and others would suggest classification of humans as multiple subspecies, if not separate species. It should also be noted that the well-known definition of a species as "organisms that can mate to produce fertile offspring" is not the standard for all geni and families.
As for the later stages,:
Sapiens or proto-Sapiens interbred with Neanderthals even earlier than the widely accepted cca 40kya admixture date; somewhere between 430kya and 270kya Sapiens dna enters Neandertal genome. While most of it was eventually bred out, mtDNA remained and all later Neandertal populations carried Sapiens mtDNA, with their original mtDNA disappearing
The reason for noncongruent out of Africa migration dates is that at least two occurred; other than the generally accepted cca 70kya migration, there was an earlier one which was limited to coastal areas of Arab peninsula, Indian subcontinent and SE Asia until it reached the previously unpopulated area behind the Wallace line, where it resulted in PNG and Australian aboriginal populations.
The reason for coastal-only migration until PNG was that those areas were already inhabited by Neanderthals and Denisovans whom Sapiens was unable to outcompete.
Only after Toba eruption (75kya) do those populations become weakened enough for Sapiens to outcompete them and that's when we see first successful migration to Middle East.
That seems to be what happened with Neanderthals, at least at first.
Incidentally any violence may have been from the Neanderthals because almost all of the genetic data shows Neanderthal ancestry from Neanderthal males and homo sapiens females, and not the other way around.
Even when this did happen[1], the record seems to show trickles of gene-flow from these populations entering a much larger stream of genes from a more recently out-of-Africa population.
[1] And in a big complex world, it certainly would have happened sometimes.
The only unexpected finding here is that this homo sp. got to an island that is surrounded by water. I have a feeling that this species is a Denosovian, but unless they can get some DNA out we won't know. We do know that the Denosovian knew how to travel over open ocean as they made it to Australia and PNG.
This is incorrect. We know Denisovans only from one cave in Siberia. From there we have DNA sequences, and from those we can tell Denisovans interbred with some homo sapiens, including people now in Australia and PNG (up to 6% of their DNA is Denisovan). There is no evidence that Denisovans themselves travelled that far.
What is now happening is that the out of Africa theory is absorbing new facts:
- How many different migrations of homo sapiens out of Africa have there been? (probably several)
- Did any groups who spent time in Europe migrate back to Africa and contribute new genes to the African gene pool (likely)
- Did homo sapiens who left Africa encounter and breed with other hominin species? (definitely, and those other species also originated in Africa)
David Reich's book from last year, "Who We Are and How We Got Here", covers a lot of the recent discoveries.
The making and using of stone tools leave a lot of refuse that shows up in the archaeological record. If hominids keep showing up in places only accessible by boat or Olympic class swimming then are we simply missing the evidence of the enabling technologies?
You can check out https://en.wikipedia.org/wiki/Pre-Columbian_trans-oceanic_co... for some debunking.
Most places on earth, America included, are or were reachable in small watercraft at certain times of the year, even without sail, given certain weather conditions. Only the remotest islands truly required advanced seafaring for repeat navigation.
Anyway, aside from isolated boating incidents there are far more impressive stories that are buried by popular history and its political supporters - the use of Persian as a lingua franca for trade and diplomacy as far away as China, various Indian Kingdoms throughout Southeast Asia and up to the Chinese border, entire civilizations whose expanse was extremely significant but virtually nobody has heard of, successful cultural genocides on grand scales, etc.
Unless the reason these early populations have been replaced by Polynesians is because they weren’t diverse enough and faded out...
Happy to dig up the source when I get home, but I remember specifically reading a paper not so long ago about a possible alternative to that hypothesis, namely that our current species might have originated out of Asia, not Africa. In which case it might not be so difficult to reconcile these outcomes.
If you're interested, there's a great episode of The Insight podcast with Milford Wolpoff that discusses a lot of this:
https://insitome.libsyn.com/multiregionalism-is-deadlong-liv...
For example, if a million years from now, someone was to dig up a bunch of bones from a dog kennel, what would they make of all the different bones from Irish wolfhounds down to sausage dogs?
Article is poorly researched:
I was expected a secret tribe of Neanderthals to have turned up.