Word: timely
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Dates: during 2010-2010
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...epigenetics isn't evolution. It doesn't change DNA. Epigenetic changes represent a biological response to an environmental stressor. That response can be inherited through many generations via epigenetic marks, but if you remove the environmental pressure, the epigenetic marks will eventually fade, and the DNA code will - over time - begin to revert to its original programming. That's the current thinking, anyway: that only natural selection causes permanent genetic change. (See "The Year in Health 2009: From...
...genes for long necks had, very slowly, gained advantage. Darwin, who was 84 years younger than Lamarck, was the better scientist, and he won the day. Lamarckian evolution came to be seen as a scientific blunder. Yet epigenetics is now forcing scientists to re-evaluate Lamarck's ideas. (See TIME's video on Charles Darwin and Abraham Lincoln...
Published in the Italian journal Acta Geneticae Medicae et Gemellologiae, Pembrey's paper, now considered seminal in epigenetic theory, was contentious at the time; major journals had rejected it. Although he is a committed Darwinist, Pembrey used the paper - a review of available epigenetic science - to speculate beyond Darwin: What if the environmental pressures and social changes of the industrial age had become so powerful that evolution had begun to demand that our genes respond faster? What if our DNA now had to react not over many generations and millions of years but, as Pembrey wrote, within...
This shortened timetable would mean that genes themselves wouldn't have had enough years to change. But, Pembrey reasoned, 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...
...enter puberty. Boys are genetically isolated before puberty because they cannot form sperm. (Girls, by contrast, have their eggs from birth.) That makes the period around puberty fertile ground for epigenetic changes: If the environment is going to imprint epigenetic marks on genes in the Y chromosome, what better time to do it than when sperm is first starting to form...