Our species, Homo sapiens, has a more adventurous sexual history than previously realized, and all that bed-hopping long ago has left an indelible mark on the human genome.
Scientists said on Friday an analysis of genetic information on about 1,500 people from locations around the world indicated at least four interbreeding episodes tens of thousands of years ago, three with our close cousins the Neanderthals and one with the mysterious extinct human species known as Denisovans.
People living on the remote equatorial islands of Melanesia represented the only population found to possess an appreciable level of Denisovan genetic ancestry. These Melanesians, like most human populations, also had Neanderthal genetic ancestry.
The researchers found some of the genes inherited from these extinct species were beneficial for our species.
Many are involved in the immune system and likely helped protect against pathogens, and some play important roles in skin and hair biology, said University of Washington evolutionary geneticist Joshua Akey, who helped lead the study published in the journal Science.
The researchers analyzed DNA sequences from 35 people living on Northern Island Melanesia off the coast of New Guinea. These Melanesians were found to have about 2 percent Neanderthal ancestry plus an additional genetic contribution of roughly 2 to 4 percent from Denisovans.
The non-African populations studied had roughly 1.5 to 4 percent Neanderthal genetic ancestry, Akey said. African populations do not have either Neanderthal or Denisovan ancestry because those two species were never on that continent.
Denisovans, discovered in the past decade, are known only from a pinky finger bone and two teeth from a northern Siberian cave.
The robust, large-browed Neanderthals prospered across Europe and Asia from about 350,000 years ago until disappearing shortly after 40,000 years ago. Less is known about the Denisovans.
The fact that the only known Denisovan remains come from northern Siberia but that their genetic contribution is seen in people living far away in Melanesia suggests Denisovans had a broad geographic range extending across Asia, Akey said.
Binghamton University molecular anthropologist D. Andrew Merriwether said the researchers also detected a contribution to people’s genome from a fourth, unknown source.
“So this paints a picture of probably at least four species of hominins (our species and extinct human species) alive at the same time and interbreeding at times over the last 100,000 years. Definitely not something most people supposed before 10 years ago,” Merriwether said.
(Reporting by Will Dunham; Editing by Sandra Maler)
Here’s how lawyers enabling Trump’s obstruction can have their livelihoods stripped from them — by anyone
In a column for the Daily Beast, a former Democratic member of the U.S. House of Representatives laid out a simple way to force lawyers advising aides to Donald Trump to defy Congressional subpoenas -- or avoiding one themselves -- to stop giving bad advice by moving to have them disbarred.
According to Brad Miller, who represented North Carolina in Congress between 2003 and 2013, the way in which former President Bill Clinton's impeachment was handled -- and the penalty he eventually received -- is a road map for legal retaliation even if Democrats in Congress won't do it.
Lara Trump snarls at critics of ‘send her back’ for pushing a ‘biased, racially-charged narrative’
Lara Trump, the wife of President Donald Trump's son Eric, has accused CNN anchor Anderson Cooper of pushing a "biased, racially-charged narrative" after he criticized her recent defense of the Trump administration over the "send her back" scandal.
This article first appeared on Salon.
"Anyone insinuating that there was some premeditated plan to orchestrate the “send her back” chant is obviously desperate to continue pushing a biased, racially-charged narrative. #FakeNews," Trump posted to her Twitter account on Saturday. She included a link to the Washington Examiner, a right-leaning newspaper which included a quote from Cooper blasting Trump for supposedly "lying" about her role in whipping up a crowd to chant "send her back" about Rep. Ilhan Omar, D-Minn.
Trump’s trade war with China has led to foreign investments in the US drying up: report
Not only are U.S. manufacturers and farmers feeling the devastating brunt of Donald Trump's ongoing trade war with China -- among other countries -- now the New York Times reports that foreign investors no longer see America as a safe bet to park their money.
According to the report, "the once steady flow of Chinese cash into America, with Chinese investment plummeting by nearly 90 percent since President Trump took office."
With the report stating, the drop-off "stems from tougher regulatory scrutiny in the United States and a less hospitable climate toward Chinese investment, as well Beijing’s tightened limits on foreign spending," one analyst blamed the increasingly hostile trade relationship between the two countries.