A paper that came out in September 2017 by Professor Ulfur Arnason calls for a new paradigm and it’s making some waves. Professor Arnason is a neuroscientist at the University of Lund in Sweden and in the paper he places the LAST COMMON ANCESTOR of Homo sapiens sapiens (modern humans) and the Neanderthals somewhere in EURASIA, not Africa. Professor Arnason argues that the ancesotrs of the African KhoeSan and Mbuti people formed the first exodus of modern humans INTO AFRICA out of ASIA AND EUROPE. If he’s right then his research calls the Out of Africa theory (OOA) into question, once again, as so much research is now doing but it’s all being ignored, summarily!
Common belief is that the ancient human ancestors of modern humans lived somewhere in Africa and Homo sapiens evolved there first and migrated out of Africa to Europe and Asia. Most scientists hold the belief that the exact dating of this emergence out of Africa of our ancient ancestors remains to be resolved but they are ever so sure they will discover a date soon. However, the research of Professor Arnason suggests that the origination of Homo sapiens sapiens was in EURASIA NOT IN AFRICA!
Neanderthals and modern humans seem to have parted ways, at least genetically, sometime before 500 kya (thousand years ago). Arnason argues that this date places the first of our species somewhere in Eurasia and he adds this to what we know about the geographical range of Neanderthals.
Professor Arnason said, “The EXCLUSIVE occurrence of Neanderthals in EUROPE and ASIA and their ABSENCE from Africa restricts their origins to EURASIA,” and indeed it DOES! He went on to also say, “As a consequence, the origin of their sister-group (Homo sapiens sapiens; modern humans) should be placed in the SAME CONTINENT (ie: EURASIA).” He goes on saying that this hypothesis would then be in “compliance with the LCA (last common ancestor) understanding that the LCS of any two sister groups CANNOT be separated, neither in time nor space.” Amen to that!!
Neanderthal remains have NOT been found in Africa but only in Europe and Asia. This fact alone strongly suggests that Neanderthals emerged in Eurasia and if this is the case then the ancestral group they diverged from (archaic Homo sapiens) would also have been living in Eurasia, not Africa! This is the LOGICAL CONCLUSION!! And in my mind this logical conclusion has the MOST merit!!!
Homo erectus is the best candidate, as far as we know, for being the immediate ancestor of modern humans. Homo erectus is found virtually everywhere and this is why I call this species the “great explorer and adventurer.” And we know they did so as early as 1.8 million years ago! Further, there is INCREASING EVIDENCE that early human ancestors of BOTH modern humans AND Neanderthals were already present in Eurasia BEFORE the split that gave rise to Neanderthals, Denisovans, and modern humans. Additionally, we also already know that humans (Homo sapiens) lived in populations that emerged in EAST ASIA long before they appeared in Africa’s fossil record. For instance, fossil remains of archaic modern humans have been found repeatedly in CHINA and these have yielded dates of between 80-178 kyr (thousand years old).
Professor Arnason also makes reference to the data emerging from the 2016 study known as “The Simons Genome Diversity Project.” This study is considered to be a landmark genetic study. It suggests that by 200 kya modern humans were ALREADY diverging into new genetic groups!! This study supports a model in which Africans and non-Africans began to part ways (diverge) genetically close to the date associated with the earliest accepted fossils of modern humans which is around 195 kya based on the Omo fossils.
It is confusing to understand why two populations in the same region would suddenly stop intermixing for tens of thousands of years and make such a “clean break” from each other. Such “clean breaks” are typically seen after migration events and as Professor Arnason points out the deepest divergence was only observed when contrasting the genomes of the Koesan people and non-Africans!
The professor also notes that the Mallick Study in 2016 and others showed that the ancestral Hss population had begun to develop genetic substructures more than 200 kya and that age is compatible with the commonly accepted estimates of the basal divergence of extant Hss. Further analysis demonstrates that the basal divergence among extant Hss fell between non-Africans (represented by the French genome) and Africans (represented by the KoeSan and Mbuti genomes).
Professor Arnason also points out that the Simon’s Genome Project shows evidence of an additional Homo sapiens sapiens divergences involving the Yoruba who are a West African population usually believed to be the living descendants of the population responsible for founding all non-African lineages!
With this new data we can extrapolate two competing models. One “Out of Africa” but another “Out of Eurasia.” In the first model (OOA) we can see modern humans emerging in Africa with the three subspecies (Neanderthals, Denisovans, Homo sapiens) arising on the continent of Africa sometime earlier than 500 kya. Neanderthals and Denisovans would have had to have migrated out of Africa immediately after they diverged from Homo sapiens and they would have had to have NOT left any fossil remains or genetic signature.
Professor Arnason postulates that hundreds of thousands of years after other humans left Africa the ancestors of the Khoisan and Mbuti would have had to diverge away from the ancestors of the Yoruba people which would be about 200 kya in his estimation. These African population then would have had to remain separated on the same continent until the ancestral population of the Yorube migrated out of the continent and colonized Europe and Asia at least 70 kya.
In regards to the second model he proposes (the Out of Eurasia Model) the professor argues that the archaic ancestors of modern humans must have reached Eurasia BEFORE the divergence of Neanderthals, Denisovans, and Homo sapiens. Neanderthals and the Denisovans, he postulates, would have remained in Eurasia NEVER encountering Africans! Then about 200 kya Homo sapiens would have broken away from the greater Eurasian population and migrated INTO AFRICA and became the ancestors of the KhoeSan and the Mbuti people. And there had to have been a second migration around 70 kya which carried the ancestors of the Yoruba people INTO AFRICA.
It must be noted, however, that the evidence for an African divergence between Neanderthals (Hsn) and modern humans (Hss) is absent in terms of Hsn NOT being found in Africa. That means NO Neanderthal remains have been found in Africa. The professor also notes that the “molecular problems related to the Out of Africa Hypothesis are of a similar nature as these results have been interpreted just in accord with the preconception of a basal Hss divergence in Africa, a supposition that automatically followed the hypothetical placement of the Hsn/Hss divergence in that continent (Africa).”
Population divergence estimates suggest strongly that there was a significant early period reduction in interbreeding between non-Africans and the KhoeSan compared to that between non-Africans and the ancestors of the Mbuti. This same pattern of divergence is also found in the data for estimates of the Yoruba/KhoeSan and the Yoruba/Mbuit interbreeding estimates. When this information is placed into the CORRECT CONTEXT it strongly suggests that the ancestors of the KhoeSan and Mbuti parted ways long BEFORE then estimated age of 131,000 YBP (years before the present) of the 50% coalescence mark! This disparity may indicate two separate migration routes taken FROM ASIA INTO AFRICA and at somewhat DIFFERENT times.
The divergence seen between the French non-African DNA and the KhoeSan DNA indicates the divergence took place around 173,000 YBP and the divergence between non-Africans and the Mbuit took place about 171,000 YBP. Yet, this agreement between the two dates disappears at the 50% coalescence mark and shows instead that there was a non-African/KhoeSan divergence 131,000 YBP and a non-African/Mbuit divergence around 112,000 YBP.
The professor postulates that the migration routes INTO Africa taken by the KhoeSan were a southern route via the Bab el Mandeb Straights while the Mbuti and Yoruba took the Sinai route. However, he doesn’t rule out the possibility that the KhoeSan and Mbuti may have taken the same route into Africa.
Early human fossil remains found in China easily fit with the Out of Eurasia and into Africa hypothesis! That is due to the fact that there is a continuous existence of modern humans present in Asia with NO requirement for some hypothetical population from Africa that somehow later went extinct. This Out of Eurasia model also readily encompasses the EVIDENCE that Neanderthals and Homo sapiens interbred over the course of about 220 kya in EUROPE and 130 kya in SIBERIA which, by the way, is problematic for the current OOA theory!!
In the article at the link below in the comment section a comment is made claiming that there have been found fossil remains dated at 1,200,000 years ago that show the presence of Homo sapiens in the northern Iran plateau in caves in the former Iranian state of Tajikistan. I have not heard of such discoveries but I’m going to look into them and see if this is true or not. The commentator says this info is breaking info in a report by a Mr. R. Fenton but that his claims need scientific corroboration and more work. The commentator is apparently with the Sambalpur University’s history department in Odisha, India.
Another commentator points out that the typical maps showing migrations out of Africa of early modern humans and H. erectus show they went straight across the land when IN FACT the more LOGICAL route is along coastlines!! After all, these people needed WATER I’m sure!!
By the way Professor Arnason is calling his theory the “Askur/Embla Hypothesis.”
In my mind Professor Arnason’s hypothesis adds evidence for the Multiregional Theory of human evolution, that is, ancient human ancestors were EVERYWHERE AND NOT JUST IN AFRICA!!! Enough of the nice little PC Out of Africa theory already! The FOSSIL and now the GENETIC EVIDENCE SAY OTHERWISE!!!
Finally let me remind you that recently a growing number of researchers believe there were several migrations INTO Africa from Eurasia so this hypothesis is not so far-fetched. And also let me remind you that over the course of time many allegations and challenges have been made concerning the dating of AHA remains found in Africa with one of the most common being anything found outside of Africa (such as in Mexico) that predates the African dates is shut down and summarily dismissed. And further, who can forget those allegations made by some researchers claiming they were told by their bosses or university overlords to “add a zero” to the dating! In my mind the millions….zillions years old dates are QUESTIONABLE at best!! I’ll have more to say about the Out of Eurasia theory in upcoming posts.
BTW Bruce Fenton who wrote the article for Ancient News has a book out entitled “The Into Africa Theory of Human Evolution” which you can find at the Amazon.com link below.