Michael Hamar points toward a study which appears to uphold the idea, increasingly gaining acceptance, that sexual orientation varies as an expression of environmentally-triggered genetics.
“To our knowledge, this is the first example of a predictive model for sexual orientation based on molecular markers,” said Tuck C. Ngun, PhD, first author on the study and a postdoctoral researcher at the David Geffen School of Medicine of the University of California, Los Angeles.
Beyond the genetic information contained in DNA, the researchers examined patterns of DNA methylation — a molecular modification to DNA that affects when and how strongly a gene is expressed — across the genome in pairs of identical male twins.
The science of this is w-a-a-a-y over my head, but the gist of it seems to be this: The chemical environment of the womb, estrogen levels especially, influences the way that genes express themselves.
We are all acquainted with the blueprint analogy: “You’re genes are like a blueprint; they govern whether you have blue eyes, or brown or green, and whether you’re tall or short … on and on.” For most purposes, that is a useful way of thinking about it. But the reality is that it’s apparently more like a long chain of IF-THEN-ELSE statements: “IF the environment is like this, THEN that, ELSE the other thing.” (But don’t quote me; that’s merely how I’m understanding what I read.)
Definitely, researchers are closing-in on the secrets of sexual-identity and -orientation, and it’s a lot more complicated than those Bronze Age goatherders thought. Not that it will change the thinking of those people whose entire sense of worth and identity derive from smugly telling themselves that they’re good li’l boys and girls who always do exactly as they’re told, whatever they’re told. But the rest of us can comfortably ignore them.