homosexuality and nature

Homosexuality and Nature : 

Homosexuality and Nature By: Jennifer Horowitz Biology 1005 video

Homosexuality is not a Choice : 

Homosexuality is not a Choice Homosexuality happens in nature with animals. Among the species that have same sex couples are penguins, dolphins, bison, swans, giraffes, and chimpanzees. Only two animals engage in sexual behavior for pleasure, bonobos and dolphins. This shows homosexuality is not a choice for pleasure.

Do these animals look like they chose to be gay? : 

Do these animals look like they chose to be gay?

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While the new findings seem to support the idea that homosexuality is merely a natural form of sexual expression, Bagemihl believes such political questions may be beside the point. "We shouldn't have to look to the animal world to see what's normal or ethical," he says. Indeed, when it comes to answering those questions, Mother Nature seems to be keeping an open mind.

X chromosome inactivation : 

X chromosome inactivation The arrangement of a mother's genes could affect the sexual orientation of her son, according to a new study. The finding, detailed in the February issue of the journal Human Genetics, adds fuel to the decade-long debate about whether so-called "gay genes" might exist. The researchers examined a phenomenon called "X chromosome inactivation" in 97 mothers of gay sons and 103 mothers whose sons were not gay.

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Even though women have two X chromosomes, only one is functional because the other is inactivated through a process called "methylation." "It gets wrapped up in a ball and is not used with the exception of a few genes," explained study leader Sven Bocklandt of the University of California, Los Angeles. If one of the females' X chromosomes is not turned off, then there is too much genetic material, which can lead to a harmful overabundance of proteins. Down syndrome, for example, results from the presence of an extra copy of chromosome 21.

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Normally, X chromosome inactivation occurs at random: half of the cells in a woman's body will have one X chromosome inactivated, while the other half inactivates the other chromosome. However, when the researchers in the current study examined cells from the 42 mothers who had at least two gay sons, they found that about a quarter of the women in this group showed something different.

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"Every single cell that we looked at in these women inactivated the same X chromosome," Bocklandt told LiveScience. "That's highly unusual." In contrast, only 4 percent of mothers with no gay sons and 13 percent of those with just one gay son showed this type of extreme skewing. Bocklandt thinks this suggest that a mother's X chromosomes partly influences whether her son is gay or not.

Then why are their identical twins with different sexual orientations? : 

Then why are their identical twins with different sexual orientations? Research in 2005 found that identical twins differ in how their genes express themselves. Now scientists have learned that all identical twins may actually differ genetically from their partners to some degree.

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In the new study, researchers analyzed 19 pairs of identical twins. Although they did possess nearly identical genomes, closer study revealed they often differed in the number of copies of individual gene segments. For instance, one twin might be missing a segment, or possess more copies of that segment than the other twin.

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Such variations could explain why one identical twin can suffer from a disorder while the other remains healthy. Researcher Carl Bruder expected that even identical twins that appear completely alike harbor "copy number variations" when it comes to at least one site in their genomes. Identical twins emerge when a zygote — the fertilized egg that develops into an embryo — splits into two embryos. As such, they should have the same genomes. The researchers speculate that as the cells making up each embryo divide over and over again during development in the womb, mistakes occur as dividing cells shuffle copies of their DNA into daughter cells.

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But genetic differences between identical twins might also accumulate after development over a twin's life as well. "I think all our genomes are under constant change," Bruder told LiveScience. Aside from understanding more about identical twins and other multiples, "by uncovering these small genetic differences in identical twins where one of them is sick, we have a way of tying specific genetic changes to the genesis of common diseases," Bruder added. He noted they are now looking at identical twins to study aging, obesity and immunological disorders.

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With these facts the idea that homosexuality is nature should not be ignored, in fact it should be embraced. For more information please visit the website www.livescience.com