New research challenges the overarching assumption that genetic mutations occur randomly and are then either kept or discarded by natural selection. In the study, published January 14 in Genome Research, scientists found that the rate of a specific mutation with important health implications is nonrandom, occurring more or less often in different populations that have experienced specific environmental pressures over the course of generations.
University of Haifa evolutionary biologist Adi Livnat and his team analyzed tens to hundreds of millions of sperm cells from each of seven donors from Ghana and four from Europe, comparing how often mutations occurred in regions of two hemoglobin subunit genes in each group. They found that the hemoglobin S (HbS) mutation of the hemoglobin subunit beta (HBB) gene, which is known to protect against malaria but causes sickle cell disease when two copies are present, occurred more often in samples from the African cohort ...
