“The researchers isolated the nerve cells responsible for sexual attraction in nematode worms, then "flipped" a genetic switch in the brains of female worms so they became attracted to other females.”
Of course nematodes ain’t humans, and expecting such a relatively simple genetic on/off switch for homosexuality for us would be a mistake.
Gaiety is, however, abundant throughout creation. I’ve collected research on everything from gay penguins to kangaroos, from dolphins to fruit flies, from mice to guppies (1,2). I’d be hard-pressed to think of a creature on this earth that does not have some measured occurrence of gaiety. In fact, some of our closest genetic relatives, the bonobos, are almost famous for their gay sexual activity.
Not only do we see same sex attraction in most every creature, we also know how to create it. We’ve made some species gay through genetic manipulation (3,4), others by hormone exposure (5-7), and even others by brain surgery on once straight mammals (8,9). I’d not, however, expect such research on humans to be forthcoming :-).
In all, it’s kind of surprising a study on worms even makes the news.
But I suppose it’s for a reason. There are still many folks who deny the existence of homosexuality outside of humanity, and others seem to ignore it in hopes of downplaying biological causes. The desire to do so is understandable. Biological causes feel more permanent to folks who hope to change us, though that’s certainly not the case; nurture or nature may both have permanent or malleable results. While such folks would rather blame, say, distant fathers or domineering mothers, I doubt near all these gay mammals, birds, insects, and marsupials were raised under such conditions :-) (I know I wasn't and I can't stand these tactics that aim to insult some great parents).
In all, and as I’ve said before in more detail, the causes of homosexuality must include at least one prime biological cause, and that is what such research on other creatures can possibly pin down for us. Such a cause is a necessary requirement, and no nurture or psychological cause that anyone may claim can be a sufficient cause. Simply, however we are created, there must first be a switch to flip and circuitry set there in the gay mind to cause the eventual feelings of with whom you are supposed to couple, just as it’s there to cause the feeling of, say, red.
Of course, I also know many in the gay community fear such research in both our species and in others, and, as stated in the Tribune article, it may become be a double edged sword. I know there’s interest in such research on gay livestock, if not to “cure” them, then to avoid purchasing or breeding for young animals that will eventually be found gay. I mean, what breeder wants a ram who’ll only be interested in rams (10), right?
Thank goodness, though, humans are so much more than a commodity, like livestock, or nematodes :-). Thank goodness life thrives off of its diversity, not merely in spite of it, and that human morality is becoming more and more about treating each individual as we’d want to be treated, rather than the tribalistic Darwinian arms race of our past. I’m pretty sure the day will come when we will be able to alter the biology of humans to the extent that we could change which sex we innately love, but I’m also pretty sure(/hopeful :-)) that, by that time, not very many people will care.
1. Bagemihl B. 1999. Biological exuberance. New York: St. Martin's Press.
2. Vasey P. L. 2002. Same-sex sexual partner preference in hormonally and neurologically unmanipulated animals. Annual Review of Sex Research 8:141-179.
3. Ryner L. C., S. F. Goodwin, D. H. Castrillon, A. Anand, A. Villella, B. S. Baker, J. C. Hall, B. J. Taylor, S. A. Wasserman. 1996. Control of male sexual behavior and sexual orientation in drosophila by the fruitless gene. Cell 87:1079-1089.
4. Kitamoto T. 2002. Conditional disruption of synaptic transmission induces male-male courtship behavior in drosophila. Proceedings of the National Acadamy of Science 99(20):13232-13237.
5. Woodson J. C., B. W. Balleine, R. A. Gorski. 2002. Sexual experience interacts with steroid exposure to shape the partner preferences of rats. Hormones and Behavior 42:148-157.
6. Baum M. J., M. S. Erskine, E. Kornberg, C. E. Weaver. 1990. Prenatal and neonatal testosterone exposure interact to affect differentiation of sexual behavior and partner preference in female ferrets. Behavioral Neuroscience 104(1):183-198.
7. Thompson R. R., F. L. Moore. 2003. The effects of sex steroids and vasotocin on behavioral responses to visual and olfactory sexual stimuli in ovariectomized female roughskin newts. Hormones and Behavior 44:311-318.
8. Kimchi T., J. Xu, C. Dulac. 2007. A functional circuit underlying male sexual behaviour in the female mouse brain. Nature 448(7157):1009-1014.
9. Paredes R. G., M. J. Baum. 1995. Altered sexual partner preference in male ferrets given excitotoxic lesions of the preoptic area/anterior hypothalamus. Journal of Neuroscience 15(10):6619-6630.
10. Roselli C. E., K. Larkin, J. A. Resko, J. N. Stellflug, F. Stormshak. 2003. The volume of a sexually dimorphic nucleus in the ovine medial preoptic area/anterior hypothalamus varies with sexual partner preference. Endocrinology 145(2):478-483.