The occurrence of derived Neandertal traits in Sima vs. their absence in penecontemporaneous samples from southeastern Europe is fairly interesting. It might suggest that the Neandertal suite of traits first appeared in western Europe.
We tend to think of Old World H. heidelbergensis as a parental species which produced -at least in the western part of the Old World- two descendant species, sapiens and neanderthalensis, but clearly that is not the whole story. Unrelated to the current paper, but perhaps worthy of note is that these two descendant species make their appearance far apart in time, with Neandertaloid traits already in evidence very early in Europe, and modern human ones late in east Africa. We may wonder about what was taking place in the temporal gap between 600 and 200 thousand years ago, and the spatial gap between Europe and Africaa.
PLoS ONE 8(2): e54608. doi:10.1371/journal.pone.0054608
New Radiometric Ages for the BH-1 Hominin from Balanica (Serbia): Implications for Understanding the Role of the Balkans in Middle Pleistocene Human Evolution
William J. Rink et al.
Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 from Mala Balanica cave, Serbia. This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene. Inferences drawn from the morphology of the mandible BH-1 place it outside currently observed variation of European Homo heidelbergensis. The lack of derived Neandertal traits in BH-1 and its contemporary specimens in Southeast Europe, such as Kocabaş, Vasogliano and Ceprano, coupled with Middle Pleistocene synapomorphies, suggests different evolutionary forces acting in the east of the continent where isolation did not play such an important role during glaciations.
Link
Quite interesting. Good to know that it fits into the general picture of fewer Neanderthal traits in the East, before a rather late spread of Neanderthals east of central Europe.
ReplyDeleteThere have been Middle Pleistocene finds in North Africa (and the Levant?) that early on were designated erectus rather than heidelbergensis. However, if they also show the trend of growing brain size and smaller dentition, one should perhaps view heidelbergensis more as a supergroup with the common development of very important shared traits (also in Africa), but local differences in globally not-so-important features (cold adaptation in the northwest; retention of more archaic features in some localities).
As I have mentioned numerous times, unless one wants to invoke rather unlikely parallel development, the important shared evolving traits make it highly likely that there were multiple events of (likely bidirectional) gene flow between Europe, the Levant, and Africa until around 300,000-400,000 ya - as expected from climatic considerations.
What if some of these early hominids (like Neanderthal) dealt with environmental changes or non-friendly hominids by moving as a group?
ReplyDeleteMaybe they were intelligent enough to have a sense of their Neanderthal-ness and cared enough to preserve it by relocating if needed.
I have wondered the same thing about Heidelberg-Rhodesiensis similarities. Could it be that these were not simply (or exclusively) general evolutionary trends among contemporary hominids, but footprints here and there of a wandering Heidelberg-Rhodesiensis-Neanderthal population?
"unless one wants to invoke rather unlikely parallel development, the important shared evolving traits make it highly likely that there were multiple events of (likely bidirectional) gene flow between Europe, the Levant, and Africa until around 300,000-400,000 ya."
ReplyDeleteAnd possibly more recently. The idea that the human species (or any other species) has evolved from a single isolated population should by now be laid completely in its grave. Species evolve by the mixing of genes that have become fixed in various sub-populations (subspecies?).
"and the spatial gap between Europe and Africa."
ReplyDeleteand the possible different routes out of Africa i.e. a possible atlantic coast northwards route and an eventually more successful arabian route.