One gene, one gender preference

For Fruit Flies, Gene Shift Tilts Sex Orientation - New York Times

Gender behavior in the fruit fly is specified with a single gene.

"We have shown that a single gene in the fruit fly is sufficient to determine all aspects of the flies' sexual orientation and behavior," said the paper's lead author, Dr. Barry Dickson, senior scientist at the Institute of Molecular Biotechnology at the Austrian Academy of Sciences in Vienna. "It's very surprising.

"What it tells us is that instinctive behaviors can be specified by genetic programs, just like the morphologic development of an organ or a nose."...

...The finding supports scientific evidence accumulating over the past decade that sexual orientation may be innately programmed into the brains of men and women. Equally intriguing, the researchers say, is the possibility that a number of behaviors - hitting back when feeling threatened, fleeing when scared or laughing when amused - may also be programmed into human brains, a product of genetic heritage.

One might think a fly is quite different from a human, but genes that code for things as fundamental as gender preference tend to be highly conserved by evolution. If there's a similar gene in humans it may well have a significant effect on male gender behavior. (Gender preference in female humans is thought to more fluid than in male humans; we may not be the same as the fruit fly.)

The more we learn, the more programmed and machine-like humans seem. The research has been pretty consistent over the past 20 years. When popular books strive to preserve a role for the environment they provide examples that are frail and tend to fall quickly to further research. In contrast genetic control of behavior has held up well. Identical twin studies seemed to preserve more room for the environment, but since then we've learned that there's a large amount of variability in gene expression even among identical twins (esp. female twins).

What will we do with this knowledge? How will it alter our thinking on self-determination, on "merit", on responsibility, on punishment? If modern Republicanism rewards the luck of parental wealth, does not the meritocratic alternative reward the luck of parental genes? (Parental wealth and parental genes, of course, are generally correlated in any event.)

If we come to see all fortune, goodness and badness as merely the expressions of random chance, will we look differently at winners and losers alike? Will we one day return to the marxist doctrine of 'from each according to their means, to each according to their needs'?

Come back in twenty years and let's see.