New studies show that modern humans interbred with Neanderthals, an extinct but closely related species, after migrating out of Africa about 60,000 years ago. Now, scientists claim to have the most accurate time estimate for this mating period yet, and it’s more recent than previously thought.
According to Tekna technology news media scientific service, two comprehensive studies, including the analysis of ancient modern human skulls (Homo sapiens) in Europe and Asia, were conducted to determine the exact time period of these interactions. The results show that the two species began to mate with each other about 50,500 years ago, and this process continued for about 7,000 years, until the Neanderthals began to become extinct.
By comparison, previous estimates of mating times ranged from 54,000 to 41,000 years ago. Neanderthals, who lived in Europe and Asia, had large noses, prominent eyebrows, and relatively short and fat bodies. Meanwhile, modern humans (Homo sapiens) evolved in Africa but migrated from the continent between 60,000 and 70,000 years ago. When modern humans arrived in Europe and Asia and found Neanderthals, primitive sexual instincts made the two species unable to resist each other despite their physical differences.
“These results give us a deeper understanding of some of the earliest pioneers to settle in Europe,” said Professor Johannes Krauss. He added that the studies show that any modern human remains found outside of Africa older than 50,000 years cannot be part of a common non-African population that interbred with Neanderthals.
The scientific community already knows that Homo sapiens interbred with Neanderthals because Neanderthal DNA has been found in the genomes of modern humans. In fact, most non-Africans today inherit one to two percent of their ancestry from Neanderthals. Since then, the details of human-Neanderthal interactions have raised some of the more pressing questions in human evolutionary biology. Article Nature Led by experts from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Germany, it examined some of the oldest human genes from a skull called “Zlatý kun” found in the Czech Republic. Also examined were bone fragments from an early human population, the German Ranis, about 230 km away. In these studies, fragments of Neanderthal DNA were found that placed the mating somewhere between 45,000 and 49,000 years ago.
Meanwhile, it examined ancient genomes sequenced from DNA found in modern human bones from across Eurasia, as well as the genomes of modern humans today. The study found that modern humans exchanged genes with their sister species over a roughly 7,000-year period beginning about 50,500 years ago.
The genome-based estimate is consistent with archaeological evidence that modern humans and Neanderthals coexisted in Eurasia between 6,000 and 7,000 years ago. Benjamin Peter, genomics researcher at MPI-EVA and co-author of the paper Science“The mixing process was very complicated and may have taken a long time,” he said. “Different groups may have diverged over a period of 6,000 to 7,000 years, and some groups may have continued to mix for much longer.”
New dates also suggest that the early migration of modern humans from Africa to Eurasia was essentially over by 43,500 years ago. Researchers think Neanderthal genes related to immunity and metabolism may have helped early humans survive and thrive outside of Africa. A 2020 study found that the two species could easily produce “fertile and healthy” offspring because they were genetically similar. In the biological world, many animals are able to breach the species barrier and mate and produce healthy offspring, but rarely are the offspring fertile.
Neanderthals became extinct about 40,000 years ago. The reasons for their extinction vary, but experts have suggested that mating, climate change and violent conflicts with humans may be to blame. Our genetic code also contains echoes of another group of extinct human relatives, the Denisovans, which split from the Neanderthals. Less is known about the Denisovans, a population of early humans who lived in Asia at least 80,000 years ago and were also closely related to Neanderthals. Denisovans also interbred with humans about 50,000 years ago, meaning DNA from early hominids survives today.
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