Sunday, March 6, 2011

Gay sheep do their part for progress

The latest research conducted into homosexuality in animals adds to the mounting evidence that it is a naturally-occurring and hormonally-influenced orientation of prenatal origin.

From the Oregon Health and Science University in Portland, and the research of Charles E. Roselli, Radhika C. Reddy, and Katherine R. Kaufman, the new sheep study (concluded in Jan 2011) showed a percentage of rams which had an exclusive preference for partners of the same sex.

There was clear identification of an ovine (sheep) sexually dimorphic nucleus (oSDN) in the medial preoptic area.  This area in sheep directly corresponds to the medial preoptic area in the human hypothalamus, further bolstering the neurohormonal theory of homosexuality in humans.  Evidence showed that the size of the oSDN is organized prenatally by testosterone, the same findings in other animals that have been researched, including humans.

The size of the oSDN is associated with a ram's sexual partner preference, such that the nucleus is 2–3 times larger in rams that are attracted to females (female-oriented) than in rams that are attracted to other rams (male-oriented).  Moreover, the volume of the oSDN in male-oriented (homosexual) rams is similar to the volume in ewes.

These volume differences are not influenced by adult concentrations of serum testosterone.  Instead, it was found that the oSDN is already present in late gestation lamb fetuses (not, vert, similarday 135 of gestation) when it is not, vert, similar2-fold greater in males than in females.  Exposure of genetic female fetuses to exogenous testosterone during the critical period for sexual differentiation masculinizes oSDN volume and aromatase expression when examined subsequently on day 135.  The demonstration that the oSDN is organized prenatally by testosterone exposure points to the brain of the male-oriented ram as being under-androgenized during development.  This further backs up hypothalamic research findings in humans, all of which have shown the same results as those in sheep and other animals.

From the study:
"The sheep offers a unique mammalian model in which to study paradoxical same-sex sexual partner preferences.  Variations in sexual partner preferences occur spontaneously with as many as 8% of rams in a population exhibiting a sexual preference for other rams (male-oriented).  This is a corresponding update of previous male-oriented ram models.  Although our understanding of the biological determinants and underlying neural substrates of sexual attraction and mate selection are not complete, compelling evidence supports that neural substrates regulating sexual partner preferences are organized during prenatal development.  Neurochemical and neuroanatomical studies suggest that male-oriented ram behavior is a consequence of individual variations in brain sexual differentiation."
This isn't a single, fleeting study.  Dozens of such studies have been conducted, peer-reviewed, and repeated again and again by different scientific teams the world over, and the results are re-confirmed each time.  And this is precisely how science works.  An observation is made, a hypothesis is made, the hypothesis is tested by collecting and analyzing data, and then re-tested, peer-reviewed, and combed over in extensive detail.  This is science, not politics or religion.

Research on homosexuality in non-human animals is typically disregarded by conservative religious groups, even though our anatomy and physiology is the same as other animals.  They argue that we are made in "God's image" and are therefore cut from an entirely different cloth.  It amazes me when people with no scientific expertise try to speak definitively on scientific matters.

In a biological sense, however, there are absolutely no significant differences between humans and other mammals.  This is why medical testing is carried out on animals before people; why scientists dissect animals to understand human physiology; and why organs can be harvested from some animals (porcine heart valves, f.ex.) for use in humans.  Peel the skin away and it's all remarkably similar, from individual mitochondria right up to organ systems.

I know that scientific research can be a tough pill to swallow for those who feel threatened by it, but facts are really hard to ignore forever.  It just starts to look desperate.



Post a Comment

Please be decent and respectful, and please post all comments in English so that everyone can understand. Thanks!


Related Posts Plugin for WordPress, Blogger...