How do you like the new look? I thought it was time to jazz the blog up a little. ;) This template is called "Modern Magic," so I couldn't resist using it.
Well, no sooner do I complain about difficulties in finding interesting science articles to blog about than I come across this piece by a wonderful science writer, Olivia Judson. In this essay, called "Evolving Sexual Tension," she talks about how the different reproductive goals of males and females create opposing evolutionary forces. Traits that may make a male successful at attracting a female, such as brightly colored plumage for a bird, would be a problem for the female. (Female birds often have drab coloring so they can hide.) But since an organism gets half of its genes from its mother and half from its father, it inherits genes that from the opposite-sex parent that may hurt its own reproductive success. (Judson doesn't go into detail in her article, but genes have markers that indicate which parent they came from. These markers affect how the genes are expressed, so they may play a part in keeping females from becoming too masculine and vice versa.) The sexual traits of both genders act on each other so they can't become imbalanced. However, geneticists have complex techniques (which Judson didn't go into) that allow them to remove the constraints. When this is done, the gender that is allowed to evolve goes to its extreme--ultra-masculine males or ultra-feminine females. The downside is that the opposite-gender offspring of these extremely gendered organisms take on these traits too, so they have a harder time reproducing.
Judson must think like a science fiction writer, for she poses her own questions in the last paragraph:
I’d love to know how much of the human genome is similarly constrained, and I wonder what would happen if human males were prevented from evolving while females were allowed to keep going. I also wonder what happens in beings like hermaphrodites, where individuals are males and females both at once — how does sexual tension evolve then? Or what about those insects where males hatch from unfertilized eggs, but females have “normal” genetics — can sexual tensions be more easily resolved?
It's always interesting to learn about unusual animal traits; as a science fiction writer, they give me ideas for creating alien races. It's especially interesting to learn about gender, since it affects so much about our culture and how individuals behave. By playing with the biology of gender in fiction, one can examine how gender affects us in everyday life--and possibly come up with ways to level the playing field between the genders.