Researchers Identify Skin Color Gene
Using the human genome database, the so-called HapMap, the researchers found that SLC24A5 has just two variations. Nearly all humans of European descent have a version of the gene with one type of amino acid, threonine; nearly everyone else has another, alanine. This suggests that a so-called "selective sweep" for the gene, wherein a gene variant confers a benefit and is thus selected for, took place among European ancestors
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Uncovering this gene, however, does nothing to solve the question of why Europeans developed lighter skin in the first place--though it is believed to represent an effort to boost production of vitamin D in sun-deprived latitudes.
