The latest big finding on Neanderthals: Some 20% of caveman DNA made its way into the human genome thanks to mating between humans and Neanderthals, though people today typically have only 1% or 2% of the stuff. (People have different parts of the DNA, which collectively represent what's left of the Neanderthal genome.) The results come compliments of two studies. Standout details:
- In one study of 1,004 people, Harvard researchers wanted to determine which populations have the most Neanderthal DNA; East Asians ranked ahead of Europeans, at 1.4% versus 1.1%, respectively, Reuters reports. (Africans essentially have no Neanderthal DNA, as Neanderthals never lived there.)
- That backs up a 2013 study, notes Reuters, but the researchers went beyond previous findings with this observation: Though Neanderthals are thought to have died out on the Iberian peninsula 28,000 years ago, Spaniards exhibited some of the smallest amounts of Neanderthal DNA, at 1.07%.
- As such, Neanderthals "are not fully extinct, if you will," a co-author of the Harvard study tells the Los Angeles Times. "They live on in some of us today—a little bit."
- The second study also compared the genomes of Europeans (379 of them) and East Asians (286), and found a similar heavier "genetic signature of Neanderthals" among the latter. A co-author tells the LAT that might indicate a second series of matings happened. "It's a two-night-stand theory now."
- The University of Washington geneticist also shared this observation: Based on the amount of our genome that comes from Neanderthals, he thinks the two species "mated perhaps 300 times about 50,000 years ago," per the LAT, though it's unclear whether that happened in one wave or over generations.
- Both studies reached a shared conclusion: that natural selection smiled on the Neanderthal genes that make skin and hair tough (possibly providing thicker insulation), and they remain common in populations with Neanderthal genes today, the New York Times reports.