The researchers studied the admixture of humans and Neanderthals using 14 million archaic chromosome fragments detected in whole genomes from 27,566 Icelanders.
Though it is unclear whether the virus became pathogenic before or after the jump from animals to humans, genomic features point to a natural source for the COVID-19 coronavirus.
Nuclear and mitochondrial genome sequences from 120,000-year-old Neanderthal remains from Germany and Belgium revealed genetic ties to more recent Neanderthal populations.
