A homosexual orientation and investigations about the existence of components biological and genetics determinants / A orientação homossexual e as investigações acerca da existência de componentes biológicos e genéticos determinantes

Everton Fernando Alves (1) , Luiza Tamie Tsuneto (1)

1 UEM - Universidade Estadual de Maringá [Brasil] = State University of Maringá [Brazil] = Université d'État de Maringá [Brésil]

The male and female homosexual orientation has substantial prevalence in humans and can be explained by determinants of various levels: biological, genetic, psychological, social and cultural. However, the biological and genetic evidence have been the main hypotheses tested in scientific research in the world. This article aims to review research studies aboutthe existence of genetic and biological evidence that determine homosexual orientation. Was conducted a review of the literature, using the database MedLine/PubMed and Google scholar. The papers and books were searched in Portuguese and English, using the following keywords: sexual orientation, sexual behavior, homosexuality, developmental Biology and genetics. Was selected papers of the last 22 years. Were found five main theories about the biological components: (1) fraternalbirth order, (2) brain androgenization and 2D:4D ratio; (3) brain activation by pheromones; and (4) epigenetic inheritance; and four theories about the genetic components: (1) genetic polymorphism; (2) pattern of X-linked inheritance; (3) monozygotic twins; and (4) sexual antagonistic selection. Concluded that there were manyscientific evidence found over time to explain some of biological and genetic components of homosexuality, especially in males. However, today, there is no definitive explanation about what are the determinants of homosexual orientation components.

Mots clés: Genetic; Sexual behavior; Homosexuality; Developmental biology; Genetic.

Domaines: Génétique humaine; Immunologie; Neurobiologie

Everton Fernando Alves, Luiza Tamie Tsuneto. A homosexual orientation and investigations about the existence of components biological and genetics determinants / A orientação homossexual e as investigações acerca da existência de componentes biológicos e genéticos determinantes. Scire Salutis, 2013, 3 (1), pp.62-78. ⟨10.6008/ESS2236-9600.2013.001.0006⟩. ⟨hal-00828832⟩