Showing posts with label natural selection. Show all posts
Showing posts with label natural selection. Show all posts

Friday, June 15, 2012

New Research Confirms Genetic Component of Homosexuality

UPDATED VERSION: There's yet more bad news for the Christofascists and their "ex-gay for pay" puppets who strive to keep alive the myth that sexual orientation can change and that being gay is a "choice" this time in the form of new research out of Italy.  The study confirms that sexual orientation is genetic - even while it seems counter intuitive - and is offset in family genetic lines by the increased fertility of women who carry the homosexual gene.  Thus, the argument of the Catholic Church and the Christianists that homosexuality goes against "natural law" - a concept developed in the 13th century, a time of abject ignorance on matters of science, biology and genetics - is false when the countering benefit for perpetuation of the species is factored in.  Indeed, the Catholic Church's anti-gay arguments based on "natural law" rank right up there with condemnation of Galileo.  Not that the Church ever seems to learn from its enormous number of past mistakes. Here are excerpts from Think Progress:
 
Italian researchers have made a new discovery that solidifies the understand that homosexuality — at least in men — has a strong genetic component. Though this study does not identify a specific gay gene, which probably does not exist, it does demonstrate what role genetics play.

Andrea Camperio Ciani at the University of Padova discovered that the mothers and maternal aunts of gay men tend to have significantly more offspring than those of straight men. Tthere seems to be at least one gene on the X chromosome that creates a trade-off in men and women. The men turn out gay (and hypothetically less likely to reproduce), but the women’s fecundity increases, making them more likely to have more offspring. In a sense, the gene makes men more attracted to men, but the women more attractive to men. Not only are they more fertile and have less complications during pregnancy, but these women are also more extroverted and have few family problems and social anxieties.

This is called the “balancing selection hypothesis,” and it effectively demonstrates how male homosexuality —as documented not only in humans but hundreds of species — does not actually contradict expectations that evolution favors reproduction.  Still, homosexuality is clearly not determined by a single factor. Studies have shown, for example, that exposure to certain levels of hormones in the womb can play a role in sexuality.  .  .  .  .  But this research may help explain why female sexuality tends to be more fluid while men’s tends to be more fixed; this “trade-off” gene may just not be playing the same role.

Scientists may never fully identity what complex combination of factors determines sexuality, but there is still plenty of evidence to conclude that it is natural and healthy part of human diversity. With each new discovery about the nature of homosexuality, discrimination against people for being gay becomes more repugnantly indefensible.


Monday, February 16, 2009

Morality May Have Roots in Our Primate Ancestors

The UK's Daily Telegraph is carrying a story that will surely set the anti-evolution crowd to foaming at the mouth. Why so? Because it reports on a new study done at Emory University in Georgia that discovered monkeys and apes can make judgements about fairness, offer sympathy and help and remember obligations. Things heretofore often believed to be abilities reserved to humans and God endowed. Personally, I have no issue with religion and evolution existing side by side. I do not take the Bible literally and thus am not threatened by anything that contradict a literal reading of the Bible. Likewise, I am not so insecure and in need of having all the answers - putting God in a box if you will and checking off boxes on a list - that I cannot live with some uncertainty as to precisely how and why we humans came to be. Not so our Christianist enemies who I suspect will condemn the study findings since it runs counter to their simpleminded world view. Here are some highlights:
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Although morality has always been viewed as a human trait that sets us apart from the animals, it now appears our closest ancestors share the same scruples. Scientists have that discovered monkeys and apes can make judgements about fairness, offer sympathy and help and remember obligations. Researchers say the findings may demonstrate morality developed through evolution, a view that is likely to antagonise the devoutly religious, who see it as God-given.
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Professor Frans de Waal, who led the study at Emory University in Georgia, US, said: "I am not arguing that non-human primates are moral beings but there is enough evidence for the following of social rules to agree that some of the stepping stones towards human morality can be found in other animals." In tests carried out by Prof de Waal, the primates were given a set of tasks to carry out and rewarded with food and affection.
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A separate study found chimpanzees spontaneously helped both humans and each other during controlled tests. Prof De Waal suggests the traits may have developed through natural selection. Some anthropologists believe a sense of morality developed during the last ice age when humans were forced to band together to survive in an increasingly hostile environment.