Link between Homosexuality, Contraception and Human Longevity

Abstract

The presence of homosexual behavior in the human population represents an evolutionary puzzle, as such behavior leads to obvious reproductive disadvantages. Recently, it was revealed that the length of telomeres inherited by offspring is determined, among other things, by the age of father. Older fathers pass longer telomeres to their children. The length of telomeres is generally considered as one of the factors determining the individual life span, which suggests that children of older fathers live longer. This phenomenon may provide a plausible explanation for the persistence of homosexuality among humans. Homosexuality is a partially inheritable trait. As homosexual males do not actively pursue reproductive sex, they are much likelier to become fathers later in life, if they reproduce at all. Through delayed reproduction, homosexual and bisexual subpopulations contribute to the increasing mean length of telomeres in population, which results in the gradually increasing life span. However, longer telomeres inherited from homosexual father are passed together with the genes predisposing to homosexual behavior, which helps to sustain a substantial pool of “gay genes” despite their reproductive disadvantage. The described effects are likely to be small but may results in a significant demographical shifts (increased longevity and sustained presence of homosexual sub-population) over multiple generations. The introduction of effective contraception (and the consequent serious increase of the mean age of fathering the children) may provide a similar mechanism for extending the mean telomere length in population, with consequences for longevity and general health.