The Gene That Came to Stay. (Anthropology)
A gene thought by some scientists to foster a bold, novelty-seeking personality, as well as attention-deficit hyperactivity disorder (ADHD), apparently spread substantially in human populations over roughly the past 40,000 years, according to a new study.
One form of the gene gained evolutionary favor near the end of the Stone Age because it enhanced survival and reproduction, proposes a team led by biologist Yuan-Chun Ding of the University of California, Irvine. The form is now the second-most-prevalent variant of the so-called DRD4 gene, which codes for a type of dopamine receptor (DRD4) found on brain cells.
Ding's team theorizes that prehistoric people who trekked from Africa to distant locales may have relied on nervy, intrepid individuals to lead the journey. Many bearers of this variant of the DRD4 gene would have had the requisite personalities to head up migrating groups, Ding's group asserts in the Jan. 8 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES.
To study variations in this gene, the researchers scrutinized the DNA sequence of the gene in 600 adults from Africa, Asia, Europe, the Americas, and the Pacific.
The most common DRD4 arrangement--found in about two-thirds of people--differs slightly from several less prevalent variations of the gene, the researchers say. …