Neanderthals and other archaic humans used to be considered distant beings, with no real connection to people today. Yet discoveries in 2016 show that early humans are so close to many of us that they're in our DNA - for better or worse.
Neanderthal DNA Purged From Our Genomes
Another Neanderthal extinction is taking place, and it's happening in our genomes, according to research that found natural selection is slowly removing Neanderthal genetic variants from modern populations. The study, published in PLOS Genetics, helps to explain what happened to all of those other Neanderthal genetic signatures that were more evident right after our species - known as anatomically modern humans, or AMH - mated with Neanderthals.
"So the first generation of hybrids would have been half Neanderthal and half AMH because they had one Neanderthal parent and one AMH parent," said senior author Graham Coop, a professor at UC Davis. "Later generations of hybrids may have more or less Neanderthal ancestry depending on whether they had more Neanderthal or AMH ancestors [for example, great grandparents]."
Neanderthal-Human Sex Happened Earlier Than Thought
A child conceived 100,000 years ago from a Neanderthal and modern human mating was announced in early 2016. The woman, from Siberia, was clearly a Neanderthal, but she retained DNA from our species. It's been known that people of European and Asian ancestry today possess a small amount of Neanderthal DNA in their genomes, but the Neanderthal woman offered the first evidence that gene flow from interbreeding went from modern humans into Neanderthals as well.
The study, published in the journal Nature, "is also the first to provide genetic evidence of modern humans outside Africa as early as 100,000 years ago," said Sergi Castellano, who co-led the research and is a scientist at the Max Planck Institute for Evolutionary Anthropology.
Neanderthals Could Have Domesticated Dogs
We learned in 2016 that dogs were domesticated not just once but twice, and in two different parts of the world. As a result, "all modern dogs are directly related to two or more wolf populations," said researcher Laurent Frantz of the Wellcome Trust Paleogenomics & Bio-Archaeology Research Network at the University of Oxford. Frantz and colleagues determined that early dogs appeared in both the East and the West more than 12,000 years ago, but in Central Asia no earlier than 8,000 years ago.
"Dogs were domesticated by hunter gatherers, prior to the advent of agriculture," Frantz said. "Dogs most likely provided multiple services to humans, such as facilitating hunting or providing protection."
The researchers can't yet rule out that Neanderthals or some other ancient human first domesticated dogs. Other research teams have found possible dog remains going back to the Neanderthal era.
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