Apr 17, 2018 05:46 PM
https://aeon.co/essays/how-the-suffering...o-the-next
EXCERPT: . . . Epigenetic trauma was found in children exposed in utero during the Dutch famine of 1944 to 1945, when Nazis stopped food from reaching populations in the Netherlands. As adults, the Hongerwinter babies exposed to stress in the womb turned out overweight with impaired glucose levels and increased cardiovascular risk, compared with unexposed siblings. The cause? A lack of ‘methyl groups’ at a number of key genes. These molecules act like ‘off’ switches by attaching to the DNA helix and stifling gene transcription. For the Hongerwinter babies, this hypomethylation led to the overproduction of certain proteins that affect growth and metabolism, triggering a cascade of cellular interactions that trended toward disease. While these epigenetic effects are uneven, the mode of transmission was surprisingly direct – stress from the mother impacted the gene expression of the developing foetus, greatly increasing the offspring’s disease risk.
Those findings apply to a single generation, yet they tug at the edges of evolutionary theory, in which species change slowly over millennia, not rapidly over the months or years of a single life. [...]
Some of the most important work in the field comes from the neuroendocrinologist and stress expert Bruce McEwen at Rockefeller University in New York, who has been studying epigenetic change caused by poverty, addiction and family violence. [...] Epigenetic changes can occur during an individual’s lifetime or be induced by pregnant mothers when their stress hormones reach the womb. But can they be passed down the generations?
Yes, says Michael Skinner, an evolutionary biologist at Washington State University. He and colleagues report that ‘environmentally induced epigenetic transgenerational inheritance has now been observed in plants, insects, fish, birds, rodents, pigs and humans’. In rodents, such changes can last at least 10 generations and, in plants, hundreds. In an extraordinary and disturbing series of experiments conducted over the course of years, Skinner has shown just how devastating epigenetic damage can be....
MORE: https://aeon.co/essays/how-the-suffering...o-the-next
EXCERPT: . . . Epigenetic trauma was found in children exposed in utero during the Dutch famine of 1944 to 1945, when Nazis stopped food from reaching populations in the Netherlands. As adults, the Hongerwinter babies exposed to stress in the womb turned out overweight with impaired glucose levels and increased cardiovascular risk, compared with unexposed siblings. The cause? A lack of ‘methyl groups’ at a number of key genes. These molecules act like ‘off’ switches by attaching to the DNA helix and stifling gene transcription. For the Hongerwinter babies, this hypomethylation led to the overproduction of certain proteins that affect growth and metabolism, triggering a cascade of cellular interactions that trended toward disease. While these epigenetic effects are uneven, the mode of transmission was surprisingly direct – stress from the mother impacted the gene expression of the developing foetus, greatly increasing the offspring’s disease risk.
Those findings apply to a single generation, yet they tug at the edges of evolutionary theory, in which species change slowly over millennia, not rapidly over the months or years of a single life. [...]
Some of the most important work in the field comes from the neuroendocrinologist and stress expert Bruce McEwen at Rockefeller University in New York, who has been studying epigenetic change caused by poverty, addiction and family violence. [...] Epigenetic changes can occur during an individual’s lifetime or be induced by pregnant mothers when their stress hormones reach the womb. But can they be passed down the generations?
Yes, says Michael Skinner, an evolutionary biologist at Washington State University. He and colleagues report that ‘environmentally induced epigenetic transgenerational inheritance has now been observed in plants, insects, fish, birds, rodents, pigs and humans’. In rodents, such changes can last at least 10 generations and, in plants, hundreds. In an extraordinary and disturbing series of experiments conducted over the course of years, Skinner has shown just how devastating epigenetic damage can be....
MORE: https://aeon.co/essays/how-the-suffering...o-the-next