Over at The Green Grok, a look at the subject of epigenetics and the results of some initial experiments on the complex interaction between common chemicals and the activation or deactivation of certain genes—and the extent to which the traits triggered by these epigenetic changes can potentially affect future generations.

In one seminal example of the role epigenomes play, adding BPA (a compound traditionally added to some plastic containers) to the diet of mice was able to turn on the agouti gene, a gene that makes mice yellow, sickly and obese. The mice whose agouti gene had been turned on tended to be more obese, yellow and sickly than their genetically identical siblings (see photo). The clear implication: our epigenome and our genome play a profoundly important part of determining who we are.

But wait, there’s more:

Last February Mohan Manikkam of Washington State University and colleagues reported results in the journal PLoS ONE that hint that transgenerational endocrine disruption can be triggered in rats by fetal exposure to a wide variety of chemicals. These include a pesticide mixture (permethrin and insect repellant DEET), a plastic mixture (bisphenol A and phthalates), dioxin (TCDD) and a hydrocarbon mixture (jet fuel, JP8).

I recommend reading the whole thing, and then perhaps renting The Incredible Shrinking Woman.