There's a new
study out which strongly suggests a biological basis for homosexuality.
I know you are likely already convinced of this, as I am, but this latest study was the first designed to rule out social effects and focus strictly on biological effects.
WASHINGTON (AP) - Men who have several older brothers have an increased chance of being gay, researchers say, a finding that adds weight to the idea that sexual orientation has a physical basis.
The increase was seen in men with older brothers from the same mother - whether they were raised together or not - but not those who had adopted or stepbrothers who were older.
"It's likely to be a prenatal effect," said Anthony F. Bogaert of Brock University in St. Catharines, Canada, who did the research. "This and other studies suggest that there is probably a biological basis" for homosexuality. [...]
S. Marc Breedlove, a professor in the neuroscience and psychology department of Michigan State University, said the finding "absolutely" confirms a physical basis.
"Anybody's first guess would have been that the older brothers were having an effect socially, but this data doesn't support that," Breedlove said in a telephone interview.
The only link between the brothers is the mother and so the effect has to be through the mother, especially since stepbrothers didn't have the effect, said Breedlove, who was not part of the research.
Well, that's your viewpoint if you're into objective reasoning. Where's this study appearing?
His findings are reported in a paper appearing in Tuesday's issue of Proceedings of the National Academy of Sciences.
Hmm, that's a pretty distinguished journal. Maybe the religious right will have an objective look at it too?
Tim Dailey, a senior fellow at the conservative Center for Marriage and Family Studies disagreed.
"We don't believe that there's any biological basis for homosexuality," Dailey said. "We feel the causes are complex but are deeply rooted in early childhood development."
So, Tim, what scientific studies can you cite to back up that view?
(crickets chirping)
I see. So what makes you so sure it's not biological?
"If it is indeed genetically based it is difficult to see how it could have survived in the gene pool over a period of time," Dailey added.
Ohhhhhh, gotcha. Well, let me help, Tim. Let's take sickle-cell anemia, for example. Now, you'd think something deadly like that would have no chance to survive in the gene pool. I mean, it makes people die, which is not especially good for reproductive fitness. Not so fast:
Sickle trait provides a survival advantage over people with normal hemoglobin in regions where malaria is endemic. Sickle cell trait provides neither absolute protection nor invulnerability to the disease. Rather, people (and particularly children) infected with P. falciparum are more likely to survive the acute illness if they have sickle cell trait. When these people with sickle cell trait procreate, both the gene for normal hemoglobin and that for sickle hemoglobin are transmitted into the next generation.
See, it's not always so simple. So what might be going on here?
One possibility, he suggests, is a maternal immune response to succeeding male fetuses. The mother may react to a male fetus as foreign, but not to a female fetus because the mother is also female.
It might be like the maternal immune response that can occur when a mother has Rh-negative blood but her fetus has Rh-positive blood. Without treatment, the mother can develop antibodies that may attack the fetus during future pregnancies.
So gayness, or certain departures from "male-like" characteristics, might provide a survival advantage in some cases. There ya go, Tim.