Homosexual behavior in animals
Homosexual behavior in animals refers to the documented evidence of homosexual, bisexual and transgender behavior in animals. Such behaviors include sex, courtship, affection, pair bonding, and parenting among same sex animals. A 1999 review by researcher Bruce Bagemihl shows that homosexual behavior has been observed in close to 1,500 species, ranging from primates to gut worms, and is well documented for 500 of them. Animal sexual behavior takes many different forms, even within the same species. The motivations for and implications of these behaviors have yet to be fully understood, since most species have yet to be fully studied. According to Bagemihl, "the animal kingdom it with much greater sexual diversity — including homosexual, bisexual and nonreproductive sex — than the scientific community and society at large have previously been willing to accept." Current research indicates that various forms of same-sex sexual behavior are found throughout the animal kingdom. A new review made in 2009 of existing research showed that same-sex behavior is a nearly universal phenomenon in the animal kingdom, common across species. Homosexuality is best known from social species.
The observation of homosexual behavior in animals can be seen as both an argument for and against the acceptance of homosexuality in humans, and has been used especially against the claim that it is a peccatum contra naturam ('sin against nature'). For instance, homosexuality in animals was cited in the United States Supreme Court's decision in Lawrence v. Texas which struck down the sodomy laws of 14 states. Whether animal sexuality has logical, ethical, or moral implications in human sexuality is also a source of debate (see appeal to nature). For more about arguments regarding homosexuality in Humans, see homosexuality.
The observation of homosexual behavior in animals can be seen as both an argument for and against the acceptance of homosexuality in humans, and has been used especially against the claim that it is a peccatum contra naturam ('sin against nature'). For instance, homosexuality in animals was cited in the United States Supreme Court's decision in Lawrence v. Texas which struck down the sodomy laws of 14 states. Whether animal sexuality has logical, ethical, or moral implications in human sexuality is also a source of debate (see appeal to nature). For more about arguments regarding homosexuality in Humans, see homosexuality.
Research on homosexual behavior in animals
The presence of same-sex sexual behavior was not 'officially' observed on a large scale until recent times, possibly due to observer bias caused by social attitudes to same-sex sexual behavior, innocent confusion, or even from a fear of "being ridiculed by their colleagues." Georgetown University biologist Janet Mann states "Scientists who study the topic are often accused of trying to forward an agenda, and their work can come under greater scrutiny than that of their colleagues who study other topics." They also noted "Not every sexual act has a reproductive function ... that's true of humans and non-humans. It appears to be widespread amongst social birds and mammals, particularly the sea mammals and the primates. The true extent of homosexuality in animals is not known. While studies have demonstrated homosexual behavior in a number of species, Petter Bøckman, the scientific advisor of the exhibition Against Nature? in 2007, speculated that the true extent of the phenomenon may be much larger than was then recognized:
No species has been found in which homosexual behaviour has not been shown to exist, with the exception of species that never have sex at all, such as sea urchins and aphis. Moreover, a part of the animal kingdom is hermaphroditic, truly bisexual. For them, homosexuality is not an issue.
Some researchers believe this behavior to have its origin in male social organization and social dominance, similar to the dominance traits shown in prison sexuality. Others, particularly Joan Roughgarden, Bruce Bagemihl, Thierry Lodé and Paul Vasey suggest the social function of sex (both homosexual and heterosexual) is not necessarily connected to dominance, but serves to strengthen alliances and social ties within a flock. Others have argued that social organization theory is inadequate because it cannot account for some homosexual behaviors, for example, penguin species where same-sex individuals mate for life and refuse to pair with females when given the chance. While reports on many such mating scenarios are still only anecdotal, a growing body of scientific work confirms that permanent homosexuality occurs not only in species with permanent pair bonds, but also in non-monogamous species like sheep.
One report on sheep cited below states:
Approximately 8% of rams exhibit sexual preferences [that is, even when given a choice] for male partners (male-oriented rams) in contrast to most rams, which prefer female partners (female-oriented rams). We identified a cell group within the medial preoptic area/anterior hypothalamus of age-matched adult sheep that was significantly larger in adult rams than in ewes...
In fact, apparent homosexual individuals are known from all of the traditional domestic species, from sheep, cattle and horses to cats, dogs and budgerigars.
Researchers found that disabling the (fucose mutarotase) FucM gene – which influences the levels of oestrogen to which the brain is exposed – caused the mice to behave as if they were male as they grew up. "The mutant female mouse underwent a slightly altered developmental programme in the brain to resemble the male brain in terms of sexual preference" said Professor Chankyu Park of the Korea Advanced Institute of Science and Technology in Daejon, South Korea, who led the research. His most recent findings have been published in the BMC Genetics journal on July 7, 2010.
No species has been found in which homosexual behaviour has not been shown to exist, with the exception of species that never have sex at all, such as sea urchins and aphis. Moreover, a part of the animal kingdom is hermaphroditic, truly bisexual. For them, homosexuality is not an issue.
Some researchers believe this behavior to have its origin in male social organization and social dominance, similar to the dominance traits shown in prison sexuality. Others, particularly Joan Roughgarden, Bruce Bagemihl, Thierry Lodé and Paul Vasey suggest the social function of sex (both homosexual and heterosexual) is not necessarily connected to dominance, but serves to strengthen alliances and social ties within a flock. Others have argued that social organization theory is inadequate because it cannot account for some homosexual behaviors, for example, penguin species where same-sex individuals mate for life and refuse to pair with females when given the chance. While reports on many such mating scenarios are still only anecdotal, a growing body of scientific work confirms that permanent homosexuality occurs not only in species with permanent pair bonds, but also in non-monogamous species like sheep.
One report on sheep cited below states:
Approximately 8% of rams exhibit sexual preferences [that is, even when given a choice] for male partners (male-oriented rams) in contrast to most rams, which prefer female partners (female-oriented rams). We identified a cell group within the medial preoptic area/anterior hypothalamus of age-matched adult sheep that was significantly larger in adult rams than in ewes...
In fact, apparent homosexual individuals are known from all of the traditional domestic species, from sheep, cattle and horses to cats, dogs and budgerigars.
Researchers found that disabling the (fucose mutarotase) FucM gene – which influences the levels of oestrogen to which the brain is exposed – caused the mice to behave as if they were male as they grew up. "The mutant female mouse underwent a slightly altered developmental programme in the brain to resemble the male brain in terms of sexual preference" said Professor Chankyu Park of the Korea Advanced Institute of Science and Technology in Daejon, South Korea, who led the research. His most recent findings have been published in the BMC Genetics journal on July 7, 2010.
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