Prehistoric humans ‘understood interbreeding hazards’
PREHISTORIC HUMANS avoided inbreeding as they knew of its dangers at least 34,000 years ago, a study has found.
They developed surprisingly sophisticated social and mating networks, and deliberately sought partners beyond their family, research published in the journal Science suggests.
It has led to speculation this could partly explain why anatomically modern humans proved more successful than other species such as Neanderthals that did not avoid inbreeding.
The study – led by Cambridge University and the University of Copenhagen – warned the theory should be treated with caution and that further research was needed.
Academics examined genetic remains of four anatomically modern humans from Sunghir, an Upper Palaeolithic site in Russia.
Unusually for finds from this period, the people found buried appear to have lived at the same time and were buried together.
To the researchers’ surprise, the individuals were not closely related in genetic terms; at the very most, they were second cousins.
This is true even in the case of two children who were buried head-to-head in the same grave.
Objects and jewellery found buried with the remains suggests they may have developed rules, ceremonies and rituals to accompany the exchange of mates between groups, which perhaps foreshadowed modern marriage ceremonies and may have been similar to those still practised by hunter-gatherer communities in parts of the world today.
Lead author Professor Eske Willerslev, a fellow at St John’s College, Cambridge, said: “What this means is that even people in the Upper Palaeolithic, who were living in tiny groups, understood the importance of avoiding inbreeding.
“The data that we have suggests that it was being purposely avoided.
“This means that they must have developed a system for this purpose.”
Professor Martin Sikora, of the University of Copenhagen, said the theory should be treated with caution.
“We don’t know why the Altai Neanderthal groups were inbred,” he said. “Maybe they were isolated and that was the only option; or maybe they really did fail to develop an available network of connections.”