A groundbreaking new study has examined 5,500 genomes out of the modern individual to search for ancient DNA and has found that humans bred with the Denisovans twice. The Denisovan species were first discovered after the DNA from a very small portion of a pinkie bone and a molar tooth that was found residing inside a Siberian cave in 2008 were analyzed. It was clearly shown that these bones did not belong to Neanderthals, nor did they belong to modern humans, and that this was an entirely new species of people that scientists were looking at.
New research now indicates that humans bred with this Denisovan species more than once, and Harvard University’s David Reich has called the news groundbreaking, according to The Washington Post.
“This is a breakthrough paper. It’s a definite third interbreeding event.”
The new study shows that the breeding between humans and Denisovans didn’t just take place in Siberia, but also continued in South Asia, where humans found a new group of Denisovans and mated with them there too.
David Reich, although not involved with the research, has called the work of the University of Washington’s Sharon R. Browning and her group of scientists as a veritable “technical tour de force.”
As Browning explained, she and the team of scientists first began their research to try and find modern DNA variations that would be quite different than expected from the populations analyzed.
“We’re looking for segments of DNA in an individual that look quite different from the rest of the variation in the population.”
— The Atlantic (@TheAtlantic) March 15, 2018
As The Scientist reports, Sharon R. Browning revealed that the new study concluded that there was a second wave which led to humans and Denisovans breeding, and this time in Asia.
“In this new work with East Asians, we find a second set of Denisovan ancestry that we do not find in the South Asians and Papuans. This Denisovan ancestry in East Asians seems to be something they acquired themselves.”
When researching modern DNA for the new paper, it was found that all of those studied had a cluster of DNA which looked to be from the Altai Neanderthals. Meanwhile, some populations had a cluster that was much closer to Altai Denisovans, and this was especially true when it came to East Asians.
Surprisingly, a third cluster was also found which had nothing in common with the DNA of Neanderthals and also didn’t seem to match that of the Altai Denisovans. It was at this point that scientists determined that there had been a second movement of breeding between humans and a completely different and new group of the Denisovan species. As Browning explained, “The geography is quite suggestive.”
Humans bred with this mysterious species more than once, new study shows https://t.co/QaqS8J6FNV
— Washington Post (@washingtonpost) March 16, 2018
It has been theorized that as humans continued their migration pattern to the east, they discovered that there were two uniquely different groups of Denisovans. The Denisovans that were found in the north appear to match modern-day groups of people living in Japan, Vietnam, and China, while the second group of Denisovans was probably encountered in the southern regions.
“Maybe it was down in the southeast corner of Asia. It could possibly have been on an island en route to Papua New Guinea, but we clearly don’t know.”
Browning and her team of scientists plan to continue their research to determine if there are any other mixtures of the Denisovan species, and are particularly interested in studying the DNA of those who are of African descent.
“We’re interested in other populations around the world, especially Africa.”
The latest study on the interbreeding of humans and the Denisovan species in two separate waves can be read in the journal Cell.