Less than 10% of the genome is endemic to modern humans, and the rest are shared with ancient human relatives such as: Neanderthals, According to a new study.
Researchers also DNA It is peculiar to modern human beings brain Development and brain function. This finding suggests that the genes for brain development and function really make us genetically distinct from our ancestors.
However, it is unclear what this finding means regarding the actual biological differences between humans and Neanderthals, says Richard E, senior author of the study, an associate professor of biomolecular engineering at the University of California, Santa Cruz. .Green said.
“It’s a big problem that future work has to be unraveled,” Green told Live Science. “At least now we know where to look.”
Published Friday (July 16) in the journal for new research Science AdvancesResearchers sought to disperse genes that are unique to modern humans, rather than inherited from ancient ancestors. However, this process is tricky because humans have genetic variation that they share with Neanderthals. Two groups mateBut also because humans and Neanderthals inherited some of the same genetic variation from a common ancestor.
So researchers have developed an algorithm known as the “speedy ancestral recombination graph estimator.” This allowed us to more efficiently distinguish between the parts of the genome that modern humans inherited by mating with Neanderthals and the parts that Neanderthals had previously shared with Neanderthals. Evolutionary division between Neanderthals and humans, About 500,000 years ago..
They used algorithms to analyze 279 modern human genomes, two Neanderthal genomes and one genome. Denisovan, Another group of archaic humans.
They found that only 1.5% to 7% of the human genome is endemic to Homo sapiens, No signs of crossbreeding or ancestral mutation.
Green described the 7% value as part of the human genome, where humans are more closely associated with each other than Neanderthals and Denisovans. A value of 1.5% is the portion that contains a genetic mutation that all humans have but not Neanderthals or Denisovans.
Green said he and his colleagues were surprised at their findings. “Many of the genomes don’t seem to be unique humans,” he said. They also “we know and recognize that most of the genes contained in 1.5% to 7% of them mainly encode proteins that are known to be involved in brain development and function. I was surprised that it is a “gene that is” and not a genetic substance that is not. It is known to have certain features.
The researchers also found that human-specific mutations were caused by two different “bursts” of adaptive genetic changes that occurred about 600,000 years ago and 200,000 years ago, the authors say. It was. It is not known exactly why the genetic changes occurred at that time or what was happening in the environment to cause those changes.
Focusing on these mutations and understanding exactly what they do in the brain helps researchers understand how humans and Neanderthals differ cognitively and biologically. May be useful for.
For example, researchers could take cells into a laboratory dish and genetically edit human-specific genes to “revert” them to the Neanderthal version, Green said. It’s not the same as actually studying Neanderthals, but Green added, “it can give a molecular idea of how that change affected human history.”
Originally published in Live Science.
Only 1.5% of our genome is “unique human”
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