At least 34,000 years ago, it seems that early humans recognized that inbreeding was not desirable, and created some fairly sophisticated social and sex networks in order to avoid it, a new study has discovered.
This study was first reported in the publication Science, and evaluated genetic data from remains of anatomically humans that lived throughout the Upper Palaeolithic period when these modern humans coming from Africa had first colonized the regions of western Eurasia. These finding have suggested that these prehistoric people deliberately sought after partners who were not member of their immediate families, and indications are they were most likely linked to a much wider group network from where sexual mates were picked, so that inbreeding would be avoided.
Dangers of Inbreeding Recognized
Obviously, this indicated that our ancestors most likely were well aware of the perils associated with inbreeding, and therefore avoided it on purpose at a remarkable early period in prehistory.
The complexity, symbolism, and time which had been invested in the jewelry and other objects that had been found buried along with the remains suggests they probably developed rules, rituals and ceremonies to go along with these sexual mate exchanges, and could have been something like those that were practiced within the hunter-gatherer communities.
The researchers also believe that this early creation of these complex mating groups might explain in part the reason that anatomically modern humans were successful in surviving while other species, like the Neanderthals, did not survive. Thus, what is needed for such a conclusion is more ancient genomic data from early humans as well as Neanderthals.
All this research has been conducted by a global academic team and has been led by the University of Cambridge located in the UK, and also the University of Copenhagen, located in Denmark. They managed to sequence genomes from four people Sunghir, which is a very notorious Upper Palaeolithic site located in Russia and is thought had been inhabited around 34,000 years ago.
The human fossils that were buried at Sunghir is indeed a valuable source of data because we see usually that findings that come from this period, those people appear to have lived around the same time and had been buried together. To the surprise of these scientists is that these people were not closely related by family and were second cousins at the very most. This was true particularly where two children had been buried head-to-head within the very same grave.
What this all indicates is that even folks from the Upper Palaeolithic period, and were living in very small groups, recognized the importance of not having inbreeding within the community. The information gather from the site suggests that it was avoided on purpose.
And because of this awareness, they obviously organized a system to avoid inbreeding. If small hunter-gatherer tribes had been randomly mixing, a much higher incidence of inbreeding would have been observed.
Small Units Linked Up With Larger Networks
Ancient humans along with other hominins like the Neanderthals appear to have dwelled within small family units. These small population sizes make inbreeding within these units much more likely, whereas among the anatomically modern humans this practice ceased, and the reason is not known.
It is believed that these tiny family bands linked up with some larger networks that facilitated an exchange of mates between the groups to maintain diversity.