University of Washington geneticist PingHsun Hsieh and his colleagues found Neanderthal and Denisovan versions of some genes in the genomes of people from Melanesia. These versions have several thousand base pairs of DNA that have been duplicated or deleted in the normal human versions. Most of this altered DNA is in or near genes related to metabolism, development, the life cycle of cells, communication among cells, or the immune system.
Those gene variants are surprisingly common among Melanesian peoples, and that could mean that their effects were useful enough that natural selection favored passing them along.
“It is tempting to hypothesize that [DNA] introgression from other hominins may have played a key role in helping humans [who were] migrating out of Africa adapt to new environments by serving as a reservoir of beneficial alleles,” wrote Hsieh and his colleagues.
What is increasingly clear, however, is that many modern people still carry aspects of our extinct hominin relatives with us. The next step is to unravel exactly how those surviving bits of ancient DNA may still influence the lives and health of modern populations.
Read full, original post: Long stretches of Neanderthal and Denisovan DNA helped Homo sapiens adapt