Sexual-gender diversity: An evolutionary point of view
Por:
Salín-Pascual R.J.
Publicada:
1 mar 2015
Resumen:
Introduction
There are people with a gender incoherence between their biological
gender (phenotype) and the self-perception gender. Differences among
such condition and sexual orientation give us more subtypes of gender
and sexual diversity: transsexual, travesties and transgender,
homosexual, heterosexual, bisexual and asexual.
Objective
To review if there are well supported evidences about sexual and gender
diversity as part of evolutionary strategies.
Method
Medical and political historical documents about the birth of the
concepts of gender and sexual orientation were consulted at The National
Library of Medicine. These were updated, in a review of the scientific
literature of the last fifty years in SCOPUS, PubMed and Science Direct
systems. The following words were used: homosexuality, transsexuality,
gender and evolution.
Results
Because sexual reproduction is so indispensable and so zealously
selected, the existence of homosexuality and transsexuality is a kind of
paradox. One must wonder: why would not evolution quickly select against
behavior, which diverts an animal from sexual reproduction? Yet despite
this apparently unlikelihood homosexuality does exist. Homosexuality is
also the innate sexual preference for one's own gender or the biological
urge for same-sex coitus. So despite popular non-recognition of the
phenomenon, natural history observations have revealed a wide range of
homosexuality throughout the animal kingdom. To account for
homosexuality -or any phenomenon- using evolution, it is necessary that
it be natural, i.e. it must occur naturally without human influence.
Thus, animal behavior is used to illustrate the naturalness of
homosexuality. In essence: there are homosexual animals in nature;
therefore homosexuality is natural. Transsexuality is a gender issue,
and in psychiatry remains as a mental disease named ``gender
dysphoria''.
Discussion and conclusion
There is some biological basis for these particular human beings, in
whom the role of high levels of hormones, antibodies against
testosterone receptors, order or birth is also discussed in the present
article. To understand that humans are not a dichotomist species is the
main goal of this work, as homo sapiens differences in many aspects of
our functions are the norm.