Identically Different

PUBLISHERS WEEKLY 3 THG 6, 2013

Spector, a genetic epidemiologist, has a wealth of case studies to draw from for his research on genes and epigenetics (the mechanism by which nongenomic elements affect genes): he's the founder and director of the TwinsUK registry, home to data on over 12,000 pairs of twins. He's spent the past two decades studying genetically identical siblings; for 17 of those years, he ascribed to the "gene-centric" view of things. But he felt like he was "missing something." That turned out to be the concept of "acquired inheritance," whereby environmental, hormonal, or other external stimuli modify one's genetic makeup. Perhaps the most interesting consequence of this is that such an altered blueprint can then be passed on to future generations. But drastic changes can occur even within one's own lifetime. For example, a cabdriver in London is subjected to intense route training in order to navigate the city's intricate streets; as a result, his hippocampus a part of the brain that deals with spatial navigation becomes enlarged. However, upon retirement, the cabbie's hippocampus will likely shrink. Spector's research has far-reaching implications in fields as diverse as oncology and parenting, and it provides a new perspective on the age-old nature-vs.-nurture debate turns out they may be on the same team.