The switch
Steve Chenoweth, at the University of Queensland, is studying how genes shared by males and females may have such different effects in the sexes: "the catch from a genetic standpoint is that males and females share almost all of their genes. Because of this, many genes that benefit one sex may actually be harmful to the other." Chenoweth suggests that the development of the genes may be controlled by triggers on the sex chromosomes. He hopes that by identifying the triggers, it may be possible to find ways to combat diseases that target men or women more frequently.
Earlier studies have focused largely on hormonal differences, as discussed in Ingrid Waldron's 1983 review for Social science & Medicine. It was widely believed that behavioral differences (such as those that cause higher rates of death by violence or accident) were linked to hormonal levels, thought to be genetically determined. However, genetic factors may outweigh hormonal environments in some cases, such as that reported by Agate et al. (2006) in Neuroscience. A gynandromorphic finch demonstrated a brain that was more male on the right hemisphere and more female on the left, despite having both sides in the same hormonal environment. We may be only begining to scratch the surface of the complex relationship between genes, hormones, and brain development.
When I first started telling people that I was transitioning to male, I was asked several times whether I'd had, or planned to have, any genetic testing done. It hadn't occurred to me to wonder if I was a genetically normal female, or whether I had some genetic difference that made my womanhood intolerable. Later, watching "You Don't Know Dick" (a documentary about transgendered men), I saw a woman attributing her partner's transgender status to a hormone bath in utero. Theories about how sexual characteristics are activated are plentiful; answers are sparse. For a while, I was dead set against more research into my condition. I felt that if the cause was determined, the "birth defect" of transgenderism might be eliminated. I don't feel that way anymore, if only because as the gender puzzle unfolds in front of me, the more impossible "solving" it appears.
Earlier studies have focused largely on hormonal differences, as discussed in Ingrid Waldron's 1983 review for Social science & Medicine. It was widely believed that behavioral differences (such as those that cause higher rates of death by violence or accident) were linked to hormonal levels, thought to be genetically determined. However, genetic factors may outweigh hormonal environments in some cases, such as that reported by Agate et al. (2006) in Neuroscience. A gynandromorphic finch demonstrated a brain that was more male on the right hemisphere and more female on the left, despite having both sides in the same hormonal environment. We may be only begining to scratch the surface of the complex relationship between genes, hormones, and brain development.
When I first started telling people that I was transitioning to male, I was asked several times whether I'd had, or planned to have, any genetic testing done. It hadn't occurred to me to wonder if I was a genetically normal female, or whether I had some genetic difference that made my womanhood intolerable. Later, watching "You Don't Know Dick" (a documentary about transgendered men), I saw a woman attributing her partner's transgender status to a hormone bath in utero. Theories about how sexual characteristics are activated are plentiful; answers are sparse. For a while, I was dead set against more research into my condition. I felt that if the cause was determined, the "birth defect" of transgenderism might be eliminated. I don't feel that way anymore, if only because as the gender puzzle unfolds in front of me, the more impossible "solving" it appears.