Neanderthals and modern humans interbred around 47,000-60,000 years ago, with the interbreeding lasting for about 6,800-7,000 years, resulting in modern humans acquiring 1-2% Neanderthal DNA, according to a recently published study.
Neanderthals lived in Europe, the Mediterranean, and Central Asia from 200,000 to 24,000 years ago, were short, stout, and powerful with large braincases, and got their name from remains found in Germany's Neander Valley in 1856.
Most experts believe Neanderthals went extinct around 40,000 years ago due to factors including changing climate, interactions with humans and potentially unfamiliar illnesses or viruses like adenovirus, herpesvirus and papillomavirus.
Neanderthal DNA impacted human metabolism, disease risk, immunity, and skin pigmentation, and may have provided evolutionary advantages.
After the interbreeding period ended, approximately 5% of the modern human genome was of Neanderthal origin, but the exchange was largely unidirectional, with limited evidence of modern human DNA entering Neanderthal genomes.
Neanderthal gene flow has influenced genetic and phenotypic variation in modern humans, and Neanderthal ancestry segments have been identified across more than 300 genomes, supporting a model of a single major gene flow event.
Natural selection for positive and negative traits occurred soon after the Neanderthal gene flow.
Not all populations have the same Neanderthal DNA percentages, with Africans having the lowest, though globally, most individuals have around 2% Neanderthal DNA. A 2020 study showed that all humans possess some Neanderthal DNA which could influence various aspects of health.
This article was written in collaboration with Generative AI news company Alchemiq
Sources: Newsweek, Business Insider, Live Science, Nature World News, CBC