Researchers announced that they were able to find a unique material in DNA that could determine a man's sexuality.
At the annual American Society of Human Genetics meeting, a team of scientists led by Tuck Ngun said that they have discovered how certain DNA markers can predict a man's sexual orientation.
"To our knowledge, this is the first example of a predictive model for sexual orientation based on molecular markers," said Ngun, a researcher from the the David Geffen School of Medicine of the University of California.
The experiment was conducted on male twins, where one is a homosexual and the other was heterosexual, as well as 10 sets of brothers, who are all homosexual. After looking into the genes of all the participants, the team found specific epigenetic markers on different parts of their genome. These markers may be able to predict a man's sexual orientation correctly in seven out of ten chances.
The team said that these markers act as "switches" that can influence human behavior and function. These switches are then affected by different factors including chemical exposure and life experiences.
"Previous studies had identified broader regions of chromosomes that were involved in sexual orientation," Ngun said. "But we were able to define these areas down to the base pair level with our approach."
Despite this knowledge, scientists are still unable to find what determinant ultimately influences the development of the gene that affects sexual orientation.
"To replicate and verify, you need a sturdy preliminary finding upon which to build and expand - and that's not the case here," wrote Ed Yong in his critique of the research for the Atlantic. He added that in Ngun's situation, it may have been best if the research had not been pursued at all.
Experts also believe that even if this study's results are validated by further research, the cause behind the DNA alteration that leads to homosexuality will still be unanswered by the findings. They also cautioned the researchers that the study sample was too small to make a viable conclusion. The small study group is in fact a source of much criticism to Ngun's work.
Ngun's answer to this is that he and his team acknowledged that the study is in its infant stage and that, given their limited funding, he would have wanted to test the findings on a larger study group if given the opportunity.
"We're just looking at a small part of the overall picture," Ngun said.
Photo: Mehmet Pinarci | Flickr