Human

Photo: Entres sang les Daynes

Another study suggests that Neanderthals may have interbred with modern humans at least 40,000 years earlier than previously thought.

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An unknown species of ancient primate nearly disappeared 900,000 years ago. These ancestors of humans were on the verge of extinction approximately, according to a modern genetic analysis.

The study was published in the journal Science
and points out that this species is an unknown ancestor that lived well before Homo heidelbergensis or also Homo sapiens.

This population that lived in Africa faced a drastic population reduction, long before the emergence of our species. The population of individuals able to reproduce was reduced to just 1,280 and it took another 117,000 years to recover.

Population geneticist Haipeng Li, from the University of Sciences of China in Beijing, co-author of the study, pointed out that about 98.7% of human ancestors were “lost” in this period.

He also points out that the fossil record in Africa and Eurasia between 950,000 and 650,000 years ago is fragmented, and the discovery of this population reduction event may help explain the lack of records in that time frame.

The small population size during this period intrigues experts, indicating that these ancestors occupied a geographically restricted area with significant social cohesion to survive.

The estimate of how long this small group managed to survive is also intriguing. This period of sustained survival would suggest the need for a stable environment with adequate resources and low stress levels for the system.

“That would imply that they occupied a very localized area with good social cohesion to survive,” says Nick Ashton, an archaeologist at the British Museum in London.

“Even more surprising is the estimated length of time this small group has survived. If this is correct, then it is thought that a stable environment with sufficient resources and low stress to the system would be required,” he said.

The research was conducted with the aid of advances in DNA genome sequencing, allowing scientists to analyze the population sizes of human ancestors prior to Homo sapiens. The researchers’ method of genetic analysis provided unprecedented insight into the population dynamics of these ancient primates.

This near-extinction period coincides with the transition from the Early to Middle Pleistocene, marked by substantial climate changes, including longer and more intense glacial cycles.

In Africa, this era resulted in long periods of drought, which may have contributed to the population reduction of human predecessors and forced the emergence of new human species. Later, these species may have evolved into the common ancestor of modern humans, Denisovans, and Neanderthals.

The population of prehumans began to expand again around 813,000 years ago, although it survived and thrived, it is still unknown how.

This population bottleneck likely had a substantial impact on the genetic diversity of humans, affecting key traits such as brain size. Up to two-thirds of genetic diversity may have been lost during this crucial period in human evolution.

With international agencies*

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2023-09-01 17:50:00
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