INTELLIGENT WORLD TODAY

The results of the test are a hot commodity, desired by researchers and hackers alike. Here's what you should know before you send in your spit.

Science magazine reports:

After early modern humans emerged in Africa about 200,000 years ago, some eventually left the continent and mixed with Neandertals in the Middle East or the Arabian Peninsula, where fossils and stone tools of both groups date back to about 120,000 to 125,000 years. This group of modern humans went extinct, but their DNA persisted in the Neandertals that headed east to eventually settle in Siberia. Meanwhile, another group of modern humans left Africa much later and interbred 50,000 to 60,000 years ago with Neandertals that had headed south from Europe to the Middle East. In this later migration, Neandertals interbred with the ancestors of living Europeans and Asians, who then spread throughout Eurasia. Some of this group of modern humans also encountered Denisovans, picking up the DNA that persists today in Melanesians and some Asians.
What isn't yet known is how the encounters happened — were they peaceful meetings, or were they raids in which one group stole the females of another group?

"Eventually, geneticists should be able to show if the transfer of DNA in either direction was mainly via males, females, or about equal in proportion, but it will need a lot more data before that becomes possible," Chris Stringer, a professor and research leader in human origins at the Natural History Museum in London, told BBC.