Un roman de science fiction d'un auteur espagnol
| (with N female and M male genotypes, and let (ξ1,…, ξN) be the proportions of the female genotypes 1,…, N, and (η1,…, ηM) the proportions of the male genotypes 1,…, M, in the population at a given generation. For non overlapping generations and infinite population size, the fertility equation yields the genotype proportions (ξ′1,…, ξ′N) and (η′1,…, η′M) at the following generation: (1) with and normalizing factors, and where ψh=fh/fN, μk=mk/mM are the normalized fecundities of the female genotype h and the male genotype k respectively, with fh and mk the female and male fecundities. The product ψhμk may be interpreted as the mating probability of the genotypes h and k, while the coefficients Aihk and Bjhk ETC...) |
|PLoS ONE. 2008 Jun 18;3(6):e2282. |
Sexually antagonistic selection in human male homosexuality.
Camperio Ciani A, Cermelli P, Zanzotto G.
Dipartimento di Psicologia Generale, Università di Padova, Padova, Italy. firstname.lastname@example.org
Several lines of evidence indicate the existence of genetic factors influencing male homosexuality and bisexuality. In spite of its relatively low frequency, the stable permanence in all human populations of this apparently detrimental trait constitutes a puzzling 'Darwinian paradox'. Furthermore, several studies have pointed out relevant asymmetries in the distribution of both male homosexuality and of female fecundity in the parental lines of homosexual vs. heterosexual males. A number of hypotheses have attempted to give an evolutionary explanation for the long-standing persistence of this trait, and for its asymmetric distribution in family lines; however a satisfactory understanding of the population genetics of male homosexuality is lacking at present. We perform a systematic mathematical analysis of the propagation and equilibrium of the putative genetic factors for male homosexuality in the population, based on the selection equation for one or two diallelic loci and Bayesian statistics for pedigree investigation. We show that only the two-locus genetic model with at least one locus on the X chromosome, and in which gene expression is sexually antagonistic (increasing female fitness but decreasing male fitness), accounts for all known empirical data. Our results help clarify the basic evolutionary dynamics of male homosexuality, establishing this as a clearly ascertained sexually antagonistic human trait.