What makes humans unique? Scientists person taken different measurement toward solving an enduring enigma with a caller instrumentality that whitethorn let for much precise comparisons betwixt the DNA of modern humans and that of our extinct ancestors.
Just 7% of our genome is uniquely shared with different humans, and not shared by different aboriginal ancestors, according to a survey published Friday successful the diary Science Advances.
“That's a beauteous tiny percentage," said Nathan Schaefer, a University of California computational biologist and co-author of the caller paper. “This benignant of uncovering is wherefore scientists are turning distant from reasoning that we humans are truthful vastly antithetic from Neanderthals.”
The probe draws upon DNA extracted from fossil remains of now-extinct Neanderthals and Denisovans dating backmost to astir 40,000 oregon 50,000 years ago, arsenic good arsenic from 279 modern radical from astir the world.
Scientists already cognize that modern radical stock immoderate DNA with Neanderthals, but antithetic radical stock antithetic parts of the genome. One extremity of the caller probe was to place the genes that are exclusive to modern humans.
It's a hard statistical problem, and the researchers “developed a invaluable instrumentality that takes relationship of missing information successful the past genomes,” said John Hawks, a paleoanthropologist astatine the University of Wisconsin, Madison, who was not progressive successful the research.
The researchers besides recovered that an adjacent smaller fraction of our genome — conscionable 1.5% — is some unsocial to our taxon and shared among each radical live today. Those slivers of DNA whitethorn clasp the astir important clues arsenic to what genuinely distinguishes modern quality beings.
“We tin archer those regions of the genome are highly enriched for genes that person to bash with neural improvement and encephalon function,” said University of California, Santa Cruz computational biologist Richard Green, a co-author of the paper.
In 2010, Green helped nutrient the archetypal draught series of a Neanderthal genome. Four years later, geneticist Joshua Akey co-authored a insubstantial showing that modern humans transportation immoderate remnants of Neanderthal DNA. Since then, scientists person continued to refine techniques to extract and analyse familial worldly from fossils.
“Better tools let america to inquire progressively much elaborate questions astir quality past and evolution,” said Akey, who is present astatine Princeton and was not progressive successful the caller research. He praised the methodology of the caller study.
However, Alan Templeton, a colonisation geneticist astatine Washington University successful St Louis, questioned the authors' presumption that changes successful the quality genome are randomly distributed, alternatively than clustered astir definite hotspots wrong the genome.
The findings underscore "that we’re really a precise young species,” said Akey. “Not that agelong ago, we shared the satellite with different quality lineages.”
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