Skipping the first couple of completely irrelevant paragraphs which he usually includes for reason that escape me, He goes on to discuss a paper “The evolution of modern human brain shape” http://advances.sciencemag.org/content/4/1/eaao5961
So the RTB model would seem to include not only interbreeding with Neanderthals but also pre-modern homo sapiens? Are they linking Adam to the first “modern brain shape” homo spapien? It’s a bit over the head of a simple silicate chemist like myself, but the original paper notes that " It is intriguing that the evolutionary brain globularization in H. sapiens parallels the emergence of behavioral modernity documented by the archeological record"
Sure we have a more globular brain than Neanderthals and pre-modern Homo Sapiens. But is that what RTB sees making us human? a more globular brain than 300,000 years ago? It is a very weak argument.
RTB (Faz Rana) doesn’t even look at the case being made that Homo Erectus had language, culture, tool making industry extending back to 2 million years ago. Significant evidence is making the case that what it means to be human evolved slowly over two million years along side advancing cognitive skills, language, and culture.
Large scale Interbreeding between many human species over a long period of time is a real problem for the RTB model.
I really don’t understand that. You’re supposed to buy into evolution but not breeding between species? How did life transition from species to species without any interbreeding? If it’s biologically possible, is it wrong? We have Neanderthal DNA because breeding was biologically possible between our species and theirs. There’s no telling what other mating was going on. Some biologically capable of procreation, others not. Don’t understand the moral implications or why it’s considered such a big deal.
The RTB model as I understand it allows for interbreeding between homo sapiens and neanderthals, and presumably Dennisovans as well. But this is the first time I’ve seen the distinction between modern homo sapiens and archaic homo sapiens put so clearly. If they believe adam was created de novo as the first modern homo sapiens with a globular brain 100-35 kya then presumably they would also allow for interbreeding with archaic homo sapiens as well. Which to my way of thinking would make it even more difficult to test for differences between their model and the standard evolutionary model.
Same here. Interesting article @AJRoberts. This is an interesting twist. I think this is suspect though:
There are no intermediate globular specimens between archaic and modern humans, as would be expected if this trait evolved . Alternatively, the distinct clusters are exactly as expected if modern humans were created .
Seems to me that the discovery of archaic Homo sapiens without this trait is exactly an intermediate form. That is a minor point though. I’m honestly curious to see how this plays out.
Yes the RTB models do have interbreeding but to them it is breeding between humans and animals - bestiality. However the evidence is showing that all genus Homo were humans so interbreeding was human with human mating.
According to RTB, a globular brain means image of God. And a non-globular brain doesn’t. Seems like “image of God” is pretty arbitrary in that shape of the head in various species of the genus Homo would be the distinguishing characteristic to be called human and made in the image of God. I think that we will find that a globular brain will be a defining characteristic of recent modern homo sapiens but it will have nothing to do with what makes us human. What makes us human are behavioral characteristics like empathy, language, culture, industry, technology. All these behavioral characteristics were evolving at a slow pace for millions of years.
How else could procreation happen? Generally in the case of bestiality there’s no chance of impregnation. If procreation is biologically possible, is that really human/animal?
No settled definition but certainly broader than just Homo Sapiens of the past 40,000 years. Given the lack of consensus on what defines human, using it just for Homo Sapiens of the last 40,000 years is not supportable.
There isn’t such a sharp division between species to disallow successful interbreeding. Neanderthal, Denosivans, Homo Sapiens, and archaic Homo Sapiens were all separate species given genome sequencing. And there were numerous interbreeding events between all of these species. The results are left in all of our genomes. Interbreeding makes all these species human as they were, during this time period, culturally and technological similar. We are certainly a mix of a mix of a mix.
Wow. “Growing Neanderthal Minibrains.” Grade-school science fair projects sure are a lot more sophisticated nowadays than what I remember when I was a kid.
From Fuz’s paper: “the confluence of evidence (anatomical, behavioral, and genetic) pinpoints the origin of modern humans (us) between 150,000 to 100,000 years ago, with the appearance of modern human anatomy coinciding with the appearance of modern human behavior.” This is the current RTB model, so the dates of 100-35 kya are NOT correct.
Sorry AJ, I should have stated more clearly that I got those figures from the original paper:
“Brain shape, however, evolved gradually within the H. sapiens lineage, reaching present-day human variation between about 100,000 and 35,000 years ago.”
Fuz also noted that "Likewise, this result coheres with the most recent dates for mitochondrial Eve and Y-chromosomal Adam around 120,000 to 150,000 years ago. I note that those dates don’t have any overlap with the dates from the paper on brain shape. Is that an issue?
While I’m apologising, I’d also like to point out that the reason I saw Fuz’s article is I greatly enjoy the articles RTB puts up and make a point of checking your site daily.
So the other non-modern humans that populated the world at the time, such as Neanderthals, Denosivans, pre-modern sapiens were not humans? Even though behaviorally all the species were pretty much doing the same things including mating and having children in significant quantities that their genes persistence in our genomes today.