April Holloway | Ancient Origins | December 19, 2013
The results of an extensive analysis of a 50,000-year-old toe bone belonging to a Neanderthal woman, which was unearthed in a cave in 2010, have been long awaited.
Now, after much anticipation, the findings have finally been released by the journal Nature, and they have not disappointed. For the first time ever, researchers have completely sequenced the fossil’s nuclear DNA to the same extent and quality as that of genomes sequenced from present-day people. All around the world, news headlines shout out about incest and inbreeding and other sensationalistic statements. Sadly, they are missing the most amazing results of all.
This incredible research has revealed the following:
There is now conclusive evidence that Neanderthals bred with Homo sapiens – a fact disputed for many years.
Some scientists claimed the two species had never even met. Ancient human species, including Neanderthals, Denisovans and Homo sapiens mated with each other, resulting in an incredibly complex family tree.
The Denisovans share up to 8 percent of their genome with a “super achaic” and totally unknown species that dates back around 1 million years.
The results conflict with the theory that modern humans arose completely from one “out of Africa” migration more than 60,000 years ago that spread worldwide without mating with other early humans. About 1.5 to 2.1 percent of all people with European ancestry can be traced to Neanderthals.
Proportions of Neanderthal DNA are higher among Asians and Native Americans, who also have small percentages of Denisovan DNA. 6 percent of the genome of Australian Aborigines and indigenous Papua New Guineans belong to the Denisovan species.
The Han Chinese, native to East Asia, and the Dai people of southern China are related to both Neanderthals and Denisovans. Some indigenous people from Brazil, such as the Karitiana, are not only related to both Neanderthals and Denisovans, but they show relatively high genetic contributions from the Denisovans.
Only 96 genes responsible for making proteins in cells are different between modern humans and Neanderthals. Intriguingly, some of the gene differences involve ones involved in both immune responses and the development of brain cells in people. Somewhere within these 96 genes may lay the answer to why Neanderthals and Denisovans became extinct. And least consequential of all, the Neanderthal woman’s parents were related, possibly half-siblings, or an uncle and niece.
As evolutionary biologist Mattias Jakobsson stated, the incest finding “is more of an anecdote”.
The results from one individual cannot be applied to an entire species, in the same way that the recent discovery of an incest family in Australia does not apply to the whole of the human race. The study really highlights that no race of people on earth belongs to one ancestral group, rather we all have “proportions of ancestral groups,” said computational biologist Rasmus Nielsen of the University of California, Berkeley. What’s more, we can begin to contemplate the fact that we are all “connected to other species – extinct smart bipeds”. So many answers have been provided from just one study and yet so many questions remain.
THIS ARTICLE ORIGINALLY APPEARED AT Ancient Origins