How can two Neanderthal communities live within ten days’ walk and still remain strangers for 50,000 years?
In the Rhone Valley, the rock shelter of Grotte Mandrin, there is a partial set of Neanderthal cranial and dental fragments, known as “Thorin,” which has brought to be an unusually sharp tool in examining the social geometry of late Pleistocene Europe. The presence of ancient DNA on a molar root dates Thorin to tens of millennia outside of a lineage that was otherwise segregated during the last known Neanderthals, at a time when they occupied a landscape commonly visited by other human groups. This is to say that it is not the site of the record of the who lived there, but rather the extent to which some groups managed to evade each other.
Thorin population had 50,000 years with no other Neanderthals before and after the exchange of genes as stated by Ludovic Slimak who was the co-first author and the researcher who discovered Thorin. Even more telling of what the genome suggests of behavior as opposed to biology is the second comment of Slimak: We have 50 millennia in which two populations of Neanderthals, some ten days walking apart, lived and totally failed to notice one another. This is inconceivable to a Sapiens and demonstrates that Neanderthals would have biologically envisioned our world in completely different ways than we Sapiens do.
It was not a question of solitude, as such, but of time. The remains of Thorin are found in layers of sediments that at first made archaeologists believe that he was a late survivor, but his hereditary composition was similar to Neanderthals that were much older. Slimak had worked seven years to discover who was right, archeologists or genomicists. The impasse drove the team to an independent check: an isotope assay of the teeth of Thorin showed an existence of a cold-climate life in line with late Neanderthals, which established an uneasy mix an late man bearing an early genomic signature.
The relevance of that combination is that it weaker the view of Neanderthals as a monolithic, well-mixed population that faded away as modern humans expanded. Thorin lineage seems to have branched off the lineage to other late Neanderthals circa 105,000 years ago. The genome is a fragment of one of the oldest populations of Neanderthals in Europe, according to Martin Sikora, who is one of the senior authors of the work. Supposed that this division continued until the time when the Neanderthals were to be eliminated by the record, then at the end of Europe in time there would have been several Neanderthalian “neighbourhoods” that were not habitually interchanging mates-or, consequently, ideas.
Demographic fingerprints are also contained in genomes. The evidence of Thorin sequence is indicative of recent inbreeding, which is likely to be seen in small groups which are closed over many generations. Genetic narrowing does not require a radical external shock to have any consequence; genetic narrowing is capable of silently decreasing the spectrum of variation when climates vary, pathogens diffuse, or resource patches change position. In that perception, isolation is a process, sluggish, accretionary, and imperceptible to the naked eye unless it has been tested with DNA.
Another contextual aspect of Grotte Mandrin is the fact that the sediment is recorded to have been occupied by both the Neanderthals and modern humans at different sediment levels. The methodological engineering trick here is to enable behavioral questions to be posed at the level of individual occupations, not as opaque millennial means. However, the lineage of Thorin does not have any traces of interbreeding with the Homo sapiens despite the fact that the modern human groups lived within the same general area at various periods.
The most familiar element of the extinction story, contact is thus refocused by Thorin. Exchange did not necessarily occur close to each other. In at least one of the Neanderthal populations, the persistence was accompanied by a form of social closure which is extreme in nature and led to the creation of a pocket of independent descent that persisted until very late in the history of the Neanderthals.
