Remarks on the Origins of Homo sapiens
The topic of human origins is not directly related to the main subject of our group. Nevertheless, a few remarks may help in understanding the broader picture.
Ancient DNA research has confirmed that modern humans (Homo sapiens) were closely related to Neanderthals. They can be considered sister species (or subspecies) that ultimately descend from the same common ancestor, Homo erectus. Geneticists have also identified another related group known as the Denisovans. We learned about Denisovans mainly through ancient DNA studies, since the few fossil remains alone were insufficient for clear classification.
One of the most surprising results of genetic research is that modern Africans have virtually no Neanderthal or Denisovan ancestry, whereas modern Eurasians do. Any such ancestry found in Africa today appears to be the result of recent back-migration from Eurasia.
This observation complicates the traditional narrative of human origins. Fossil evidence shows that Homo erectus was already present in Eurasia about two million years ago, as demonstrated by discoveries at Dmanisi archaeological site. Therefore, it is theoretically possible that the three later human groups—modern humans, Neanderthals, and Denisovans—developed in Eurasia from intermediate populations such as Homo heidelbergensis.
Despite this possibility, the phylogenetic trees of Y-DNA and mitochondrial DNA still strongly support an African origin for modern humans. The most basal haplogroups, A and B, are found exclusively in Africa.
The geneticist David Reich discusses these apparent contradictions in his book Who We Are and How We Got Here as well as in various interviews.
Overall, it seems increasingly likely that human origins were more complex than the simple “Out of Africa” model suggests. One possible scenario is that early human populations may have had deep roots in Eurasia, later moved into Africa around 400–500 thousand years ago, and then re-expanded out of Africa about 100 thousand years ago.
This complexity is one reason why caution is needed when discussing the origins of very old and widespread haplogroups, such as haplogroup E.
Further research—especially additional ancient DNA samples—will be necessary to clarify these questions.
