Word: bygren
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Solving the Overkalix Mystery By early 2000, it seemed clear to Bygren that the feast and famine years in 19th century Norrbotten had caused some form of epigenetic change in the population. But he wasn't sure how this worked. Then he ran across an obscure 1996 paper by Dr. Marcus Pembrey, a prominent geneticist at University College London...
...effects of nurture (environment) on a species' nature (genes) were not supposed to happen so quickly. Charles Darwin, whose On the Origin of Species celebrated its 150th anniversary in November, taught us that evolutionary changes take place over many generations and through millions of years of natural selection. But Bygren and other scientists have now amassed historical evidence suggesting that powerful environmental conditions (near death from starvation, for instance) can somehow leave an imprint on the genetic material in eggs and sperm. These genetic imprints can short-circuit evolution and pass along new traits in a single generation. (See TIME...
...instance, Bygren's research showed that in Overkalix, boys who enjoyed those rare overabundant winters - kids who went from normal eating to gluttony in a single season - produced sons and grandsons who lived shorter lives. Far shorter: in the first paper Bygren wrote about Norrbotten, which was published in 2001 in the Dutch journal Acta Biotheoretica, he showed that the grandsons of Overkalix boys who had overeaten died an average of six years earlier than the grandsons of those who had endured a poor harvest. Once Bygren and his team controlled for certain socioeconomic variations, the difference in longevity jumped...
Meet the Epigenome The answer lies beyond both nature and nurture. Bygren's data - along with those of many other scientists working separately over the past 20 years - have given birth to a new science called epigenetics. At its most basic, epigenetics is the study of changes in gene activity that do not involve alterations to the genetic code but still get passed down to at least one successive generation. These patterns of gene expression are governed by the cellular material - the epigenome - that sits on top of the genome, just outside it (hence the prefix epi-, which means above...
...maybe the epigenetic marks atop DNA would have had time to change. Pembrey wasn't sure how you would test such a grand theory, and he put the idea aside after the Acta paper appeared. But in May 2000, out of the blue, he received an e-mail from Bygren - whom he did not know - about the Overkalix life-expectancy data. The two struck up a friendship and began discussing how to construct a new experiment that would clarify the Overkalix mystery...