An Italian research team claims that the evolutionary origin and maintenance of male homosexuality in human populations could be explained by a model of sexually antagonistic selection.
"Male homosexuality is difficult to explain under Darwinian evolutionary models, because carriers of genes predisposing towards male homosexuality would be likely to reproduce less than average, suggesting that alleles (variations of the same gene) influencing homosexuality should progressively disappear from a population.
The model show the interaction of male homosexuality with increased female fecundity (fruitfulness) within human populations, in a complex dynamic, resulting in the maintenance of male homosexuality at stable and relatively low frequencies, and highlighting the effects of heredity through the maternal line.
"Our findings provide new insights into male homosexuality in humans. In particular, they promote a focus shift in which homosexuality should not be viewed as a detrimental trait (due to the reduced male fecundity it entails, but, rather, should be considered within the wider evolutionary framework of a characteristic with gender-specific benefits, and which promotes female fecundity. This may well be the evolutionary origin of this genetic trait in human beings."
Storytellers: Andrea Camperio Ciani and Giovanni Zanzotto at the University of Padova and Paolo Cermelli at the University of Torino
Male Homosexuality Can Be Explained Through A Specific Model Of Darwinian Evolution, Study Shows
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