Natural selection has influenced the morphological and disease-related diversity of modern human populations, according to a study published online in Nature Genetics. The paper suggests that newly identified variants exhibiting reduced differentiation across populations might become medically relevant.
Several recent genome-wide studies have established that many regions of the human genome are under selection, but the degree to which this selective pressure has shaped the differences between modern human populations has been unclear.
Lluís Quintana-Murci and colleagues analyzed more than 2.8 million single-nucleotide polymorphisms (SNPs) from the second phase of the HapMap project. They show that positive selection has promoted the regional adaptation of human populations by increasing population differentiation in particular gene regions. Genes showing the strongest signature of positive selection are involved in skin pigmentation and hair development, immune response to pathogens, sensory functions such as olfaction and eye development, and insulin regulation. They also show that negative selection has reduced the degree of population differentiation in genetic variants that are associated with disease.
Lluís Quintana-Murci (Institut Pasteur, Paris, France)
Abstract available online.
(C) Nature Genetics press release.
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