As a kid sitting in High School biology class I was always left a little perplexed as in the day there was believed to be clearly delineated lines drawn between that of “environment” and “genetics” as it was around this time there was a lot of debate of what made a “bad” kid if you will. As the majority of the intellectual pundits of the day said it was “environmental“, therefore (poor) parenting and the people around them is what made bad kids “bad”. As the pro-environment folks also said all people are born equal and genetics plays no role which left me scratching my post adolescent head as what about Darwin?
Yea the fellow who set out on the Beagle and wrote about Natural Selection (you can visit his tomb in Westminster Abby near that of Newton’s, been there a couple times) which in short say we change over time in response to our environment. However the catch the environmental proponents had fallen back upon was this took many, many generational iterations to manifest so it could not play a role in a single generation model which again didn’t make sense when thinking about the law of large numbers as there are estimated to be between 20,000 and 25,000 genes. Thus even a 1% change is significant and what is even more is the fact all of these work together, so changing even 1 gene is a kin to altering the gear ratio of a huge machine risking throwing it off kilter.
However since then scientists have come to know that children whose mothers were chronically stressed during pregnancy by such things as famine, anxiety, the death of a relative or marital discord will show above average rates of various psychological and behavioral disorders when reaching adulthood. Its also been accepted for a long while that those children brought up in abusive environments often turn out to be abusive themselves. This later trend (abusiveness) has typically been attributed to “environment” as a learned response, while the reason for the first has remained unclear.
However a recent study just published by Axel Meyer, Thomas Elbert and their colleagues at the University of Konstanz in Germany, may shed some light on this phenomenon which they call “epigenetics” and is the likely answer to this question. With this said, should Drs Meyer and Elbert be proven right, it also suggests an alternative explanation for the “inheritance” of abusiveness via genetics and not environ. As “epigenetics” is a type of gene regulation that can be passed from a cell to its replicates, where the common means for this to occur is “methylation“. What happens is a methyl group (a carbon atom and three hydrogens) attach them-self’s to either adenine or cytosine, two of the four primary building blocks which form DNA, therefore depending on the gene involved. The resulting impact is the “methylated” gene is inactivated.
As you can imagine, again depending upon the gene, the results of this can be substantial. As well, this clearly demonstrates that single generational links to environmental influences which carry with it genetic implications actually exist…
Sidebar: This also leads me to wonder if this isn’t an influencing factor in the recent [perceived at minimum] leap in the appearance of Autistic Spectrum Disorders (ASD).