DIVERSE SEXUAL ORIENTATIONS

Diverse Sexual Orientations in Humans

Diverse Sexual Orientations in Humans

Introduction

Current estimates, first developed by Dr. Alfred Kinsey, indicate that approximately ten percent of the population is gay. It is believed that this proportion is more or less the same in the world, in all ages, cultures and climates. The feelings of attraction towards persons of the same sex usually appear to be both emotional and physical. In the late 40's Dr. Kinsey developed a scale that bears his name and that shows that people are not strictly homosexual or heterosexual, but fluctuate between the two. In other words, there are many men and women whose sexual orientation indicates different degrees of bisexuality.

The relationship between biology and sexual orientation is under investigation in the field of human developmental biology (Stein, 2011). No single cause has been found simple to determine the sexual orientation, but some research suggests that is the result of a complex combination of genetic influences, hormonal and environmental there are biological factors related to complex interactions of genetic and initial uterine environment.

Discussion

Studies of linkage of chromosomes on sexual orientation have noted the contribution of multiple genetic factors. In 1993, Dean Hamer and his team published their findings in the genetic analysis of a sample of 76 gay brothers and their families (Talley, Sher & Littlefield, 2010). Gay men were more gay uncles and cousins on the maternal side of their families that in the father. We studied these gay brothers who had a family history and examined the linkage of the X chromosome, using twenty-two chromosome markers for this allele similar.

A link between the genetic structure of the mother and the homosexuality of their sons. Females have two X chromosomes, one of whom is disabled. The inactive X chromosome occurs randomly during the embryonic period, so that the cells form a mosaic over which chromosome is active. But instead, in some cases, the deactivation may occur in a non-random (Gwang-Won, Jong-Chul & Gwang-Woo, 2011). Mothers of gay men, the percentage of extremely skewed inactivation of chromosome X was significantly higher than those without gay sons. 13% of mothers with a gay son and 23% of mothers with gay sons showed two extreme asymmetric inactivation, compared with 4% of mothers without gay sons.

A 33% increased chance of a boy being gay for each older brother a man has. So far, this factor is one of the epidemiological variables reliable studies identified sexual orientation. To explain this finding as hypotheses have been proposed that male fetuses provoke an immune reaction in the mother, this is becoming stronger in subsequent pregnancies of male fetuses (Smith, et. al., 2010). Male fetuses produce HY antigens, which almost certainly are involved in sexual differentiation of vertebrates. The mother is supposed to produce antibodies against this antigen react and your body will remember, each time producing a stronger attack in subsequent pregnancies of men, so the HY antigen would lose their ability to perform its function of masculinizing the brain the fetus (VanKim, Padilla, Lee ...