Saga of early humans etched in DNA of mixed-species child | 2018-08-25 | daily-sun.com

Saga of early humans etched in DNA of mixed-species child

    25 August, 2018 12:00 AM printer

Saga of early humans etched in DNA of mixed-species child

Denny was an inter-species love child. Her mother was a Neanderthal, but her father was Denisovan, a distinct species of primitive human that also roamed the Eurasian continent 50,000 years ago, scientists reported Wednesday in the journal Nature, reports AFP.

Nicknamed by Oxford University scientists, Denisova 11 — her official name—was at least 13 when she died, for reasons unknown. “There was earlier evidence of interbreeding between different hominin, or early human, groups,” said lead author Vivian Slon, a researcher at the Max Planck Institute for Evolutionary Anthropology.

“But this is the first time that we have found a direct, first-generation offspring,” she told AFP.

Denny’s surprising pedigree was unlocked from a bone fragment unearthed in 2012 by Russian archeologists at the Denisova Cave in the Altai Mountains of Siberia.

Analysis of the bone’s DNA left no doubt: the chromosomes were a 50-50 mix of Neanderthal and Denisovan, two distinct species of early humans that split apart between 400,000 to 500,000 years ago.

“I initially thought that they must have screwed up in the lab,” said senior author and Max Planck Institute professor Svante Paabo, who identified the first Denisovan a decade ago at the same site.

Worldwide, fewer than two dozen early human genomes from before 40,000 years ago—Neanderthal, Denisovan, Homo sapiens—have been sequenced, and the chances of stumbling on a half-and-half hybrid seemed vanishingly small.

Or not.

“The very fact that we found this individual of mixed Neanderthal and Denisovan origins suggests that they interbred much more often than we thought,” said Slon. Paabo agreed: “They must have quite commonly had kids together, otherwise we wouldn’t have been this lucky.”

A 40,000 year-old Homo sapiens with a Neanderthal ancestor a few generations back, recently found in Romania, also bolsters this notion.

But the most compelling evidence that inter-species hanky-panky in Late Pleistocene Eurasia may not have been that rare lies in the genes of contemporary humans.

About two percent of DNA in non-Africans across the globe today originate with Neanderthals, earlier studies have shown.

Denisovan remnants are also widespread, though less evenly.

“We find traces of Denisovan DNA—less than one percent—everwhere in Asia and among native Americans,” said Paabo.


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