Gender genetics and sexual orientation evolution

Image by Nathan Appel.

Two articles, one about male and female genes battling for domination as an ongoing life-long struggle, and one on asexuality as the fourth sexual orientation really caught my eye. I apologize that I can’t remember where I found them (the via), but since I can’t get them out of my head I thought you might find them as intriguing as I did…

Battle of the sexes – one gene keeps us either male or female, scientists find

Researchers have found that the body is in a constant fight to remain either female or male and the suppression of just one gene could cause it to “flip” from one to the other. The remarkable findings refute the generally held view that sex is determined at birth and is irreversible in later life. They could also lead to treatments for certain gender disorders in children, early menopause in women and even eventually non-surgical sex changes.

In mammals, males have XY chromosomes and females XX. The new research shows that another gene is responsible for switching women into men. If the FOXL2 is switched on then the body grows ovaries, switched off and they are replaced by testicles.

But what really surprised the researchers is that the process continues after birth and the body remains in a constant tussle to either switch on or off the gene – even in adulthood. (…read more, telegraph.co.uk)

The fourth sexual orientation?
With asexuals coming out of the closet, scientists ponder whether it’s choice or biological imperative

It wasn’t much of a mystery. After all, lust isn’t exactly a subtle thing. Back then I derived as much pleasure from making out with my “girlfriend” as I might have from scraping the plaque from my dog’s teeth. In contrast, barely touching legs with a boy I had a crush on sparked an electric, ineffable ecstasy. The point is, whether or not we like, hide or accept what we are, our true identities – gay, straight, bisexual – consciously dawn on each of us during adolescence. We all have a natural “orientation” towards sexual contact with others, and for the most part we’re just hopeless pawns to our body’s desires.

At least, that’s what most people tend to think. But some scientists believe that there may be a fourth sexual orientation in our species, one characterized by the absence of desire and no sexual interest in males or females. Such people are regarded as asexuals. Unlike bisexuals, who are attracted to both males and females, asexuals are equally indifferent to and uninterested in having sex with either gender. So imagine being a teenager waiting for your sexual identity to express itself, waiting patiently for some intoxicating bolus of lasciviousness to render you as dumbly carnal as your peers, and it just doesn’t happen. These individuals aren’t simply celibate, which is a lifestyle choice. Rather, sex to them is just so … boring. (…read more, thestar.com)