Epigenetics
24th August 2008
Nancy Kress introduces a fascinating subject that is undeservedly off the radar of most people. I, for one, intend to poke into it much more heavily, and I would encourage you to do the same.
The surprise comes in Epigenesis III. Some traits acquired in mothers as a result of how their patterns of cells react to environmental toxins seems to be inherited by their offspring. This sounds almost LaMarckian, but there is proof from experiments with agouti mice. Mice with identical genomes (they were clones) were exposed to high concentrations of BPA (that’s the same toxin being yelled about with regard to plastic water bottles). The offspring of those so exposed were a different color (yellow rather than brown) and gained weight easily. This might have been construed as damage to their genomes — except that the new offspring were then not exposed to any more BPA, and still their offspring showed heritable patterns of color and weight gain, presumably as a result of the passing on of Gen II’s epigenetic patterns. And the abnormalities were reversed by feeding the mice diets high in soy, indicating they were not set-in-stone genetic instructions.
And read Nancy’s books too, of course. I guarantee you’ll like them. If you can read Beggars in Spain and not immediately devour every piece of her writing you can get your hands on, well, the angels will weep for you. She’s got a new one out, Dogs, the delivery of which I am awaiting with sweaty palms.