
For whom would that make a difference? From an online book in progress by Stephen L. Talbott, tentatively titled “Evolution As It Was Meant To Be — And the Living Narratives That Tell Its Story” (Overview), at the Nature Institute:
“Are genes equivalent to destiny?” in a new light. In 2007 a team of researchers at Duke University reported that exposure of pregnant mice to bisphenol A (a chemical that was then used in many common plastics such as baby bottles and dental composites) “is associated [in the offspring], with higher body weight, increased breast and prostate cancer, and altered reproductive function“. The exposure also shifted the coat color of the mice toward yellow — a change again found to be transmitted across generations despite its not being linked to a gene mutation. Moreover, the changes brought on by the chemical were negated when the researchers supplemented the maternal diet with folic acid, a B vitamin (Dolinoy et al. 2007).
And so an epigenome that responds to the environment can respond to healthy as well as unhealthy influences. As another illustration of this: researchers at McGill University in Montreal looked at the consequences of two kinds of maternal behavior in rats. Some mother rats patiently lick and groom their newborns, while others generally neglect their pups. The difference turns out to be reflected in the lives of the offspring: those who are licked grow up (by the usual measures) to be relatively confident and content, whereas the neglected ones show depression-like symptoms and tend to be fearful when placed in new situations.
This difference is correlated with different levels of activity in particular genes in the hippocampus of the rats’ brains. Not that the gene sequences are themselves mutated in the usual sense. Rather, the researchers found that various epigenetic modifications in the hippocampus alter the way the genes work (Weaver et al. 2004). Other investigations have pointed toward similar changes in the brains of human suicide victims who were abused as children (Poulter et al. 2009).
What has perhaps excited the general public most is this application of epigenetic studies to human beings…
Stephen L. Talbott, “All Genetics Is Epigenetics” at Evolution as it Was Meant to Be: A work in progress
Hat tip: Philip Cunningham
See also: Life forms have a story but rocks don’t Talbott: An animal’s end-directed activity may, of course, be very far from what we humans know as conscious aiming at a goal. But all such activity nevertheless displays certain common features distinguishing it from inanimate proceedings
Is today’s biology missing a Big Idea? Talbott: Every organism is an entity in which certain ideas and intentions are manifest — observably expressed and realized. We have to be willing to say, as everyone does say, “This cell is preparing to divide.” We would never say (as I mentioned earlier), “This planet is preparing to make another circuit of the sun.”
There’s a gene for that… or is there?
and
Epigenetic change: Lamarck, wake up, you’re wanted in the conference room!
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