282 research outputs found

    The development and evolution of male androphilia in Samoan fa'afafine

    Get PDF
    xvii, 201 leaves : ill. ; 29 cmMale androphilia (i.e., male sexual attraction to males) is an evolutionary paradox. It is unclear how genes for male androphilia persist given that androphilic males have lowered reproduction? Evidence suggests that ancestral androphilic males were transgendered. Hence, I address this paradox by focusing on a group of Samoan transgendered androphilic males (i.e., fa’afafine). Specifically, I show that male androphilia has consistent developmental correlates across Samoan and Western populations, indicating that fa’afafine provide a suitable model for the evolution of male androphilia across populations. In addition, I test hypotheses concerning the evolution of male androphilia. Fa’afafine’s mothers and grandmothers exhibit elevated reproduction. Also, compared to Samoan men and women, fa’afafine exhibit unique kin-investment cognition that would enhance indirect fitness. Elevated reproduction by female kin, and enhanced kin investments may, therefore, contribute to the evolution of male androphilia. Lastly, I outline a developmental model for this unique kin-investment cognition in androphilic males

    A Problematic Test of the Kin Selection Hypothesis Among the Urak-Lawoi of Ko Lipe, Thailand: Commentary on Camperio Ciani, Battaglia, and Liotta (2015)

    Get PDF
    Camperio Ciani et al. argued that the Urak-Lawoi people of Ko Lipe island live in a ‘‘traditional,’’ ‘‘subsistence primitive society’’ reminiscent of the ‘‘ancestral’’ human past and that their socio-cultural situation is ‘‘remarkably similar’’ to Samoa. On this basis, they asserted that the Ko Lipe Urak-Lawoi are an appropriate population for determining the role that kin selection played in the evolution of male androphilia. The purpose of this commentary is to outline some of our concerns with this characterization and with the statistical analyses conducted by Camperio Ciani et al. in their study of the Urak-Lawoi

    A Problematic Test of the Kin Selection Hypothesis Among the Urak-Lawoi of Ko Lipe, Thailand: Commentary on Camperio Ciani, Battaglia, and Liotta (2015)

    Get PDF
    Camperio Ciani et al. argued that the Urak-Lawoi people of Ko Lipe island live in a ‘‘traditional,’’ ‘‘subsistence primitive society’’ reminiscent of the ‘‘ancestral’’ human past and that their socio-cultural situation is ‘‘remarkably similar’’ to Samoa. On this basis, they asserted that the Ko Lipe Urak-Lawoi are an appropriate population for determining the role that kin selection played in the evolution of male androphilia. The purpose of this commentary is to outline some of our concerns with this characterization and with the statistical analyses conducted by Camperio Ciani et al. in their study of the Urak-Lawoi

    TransCom N2O model inter-comparison - Part 2:Atmospheric inversion estimates of N2O emissions

    Get PDF
    This study examines N2O emission estimates from five different atmospheric inversion frameworks based on chemistry transport models (CTMs). The five frameworks differ in the choice of CTM, meteorological data, prior uncertainties and inversion method but use the same prior emissions and observation data set. The posterior modelled atmospheric N2O mole fractions are compared to observations to assess the performance of the inversions and to help diagnose problems in the modelled transport. Additionally, the mean emissions for 2006 to 2008 are compared in terms of the spatial distribution and seasonality. Overall, there is a good agreement among the inversions for the mean global total emission, which ranges from 16.1 to 18.7 TgN yr(-1) and is consistent with previous estimates. Ocean emissions represent between 31 and 38% of the global total compared to widely varying previous estimates of 24 to 38%. Emissions from the northern mid- to high latitudes are likely to be more important, with a consistent shift in emissions from the tropics and subtropics to the mid- to high latitudes in the Northern Hemisphere; the emission ratio for 0-30A degrees N to 30-90A degrees N ranges from 1.5 to 1.9 compared with 2.9 to 3.0 in previous estimates. The largest discrepancies across inversions are seen for the regions of South and East Asia and for tropical and South America owing to the poor observational constraint for these areas and to considerable differences in the modelled transport, especially inter-hemispheric exchange rates and tropical convective mixing. Estimates of the seasonal cycle in N2O emissions are also sensitive to errors in modelled stratosphere-to-troposphere transport in the tropics and southern extratropics. Overall, the results show a convergence in the global and regional emissions compared to previous independent studies

    Elucidating the origins of heterosexual sex differences in mating psychology by examining the behaviour of homosexual men and women

    Get PDF
    x, 73 leaves ; 28 cm. --Various competing theoretical frameworks have been invoked to explain heterosexual sex differences in mating psychology. Chapter One provides examples of such frameworks, details how considering both heterosexual and homosexual men and women can help identify the most tenable frameworks, and reviews previous research comparing the mating psychology of heterosexual and homosexual men and women. Chapter Two demonstrates the utility of this comparative method by examining the mate retention behaviour of heterosexual and homosexual men and women. Where heterosexual sex differences exist, the mate retention behaviour of homosexual men is largely sex-typical while that of homosexual women is sex-atypical. The significance of these results for explaining heterosexual sex differences in mate retention is discussed. Chapter Three discusses how the data presented and reviewed here might inform our understanding of the psychological mechanisms underlying mating psychology as well as the development of sexual orientation in men and women

    Offspring Production among the Extended Relatives of Samoan Men and Fa'afafine

    Get PDF
    Androphilia refers to sexual attraction to adult males, whereas gynephilia refers to sexual attraction to adult females. Male androphilia is an evolutionary paradox. Its development is at least partially influenced by genetic factors, yet male androphiles exhibit lower reproductive output, thus raising the question of how genetic factors underlying its development persist. The sexual antagonism hypothesis posits that the fitness costs associated with genetic factors underlying male androphilia are offset because these same factors lead to elevated reproduction on the part of the female relatives of androphilic males. Western samples drawn from low fertility populations have yielded inconsistent results when testing this hypothesis. Some studies documented elevated reproduction among the matrilineal female kin of androphilic males, whereas others found such effects in the paternal line. Samoa is a high-fertility population in which individuals reproduce closer to their maximum capacities. This study compared the reproductive output of the paternal and maternal line grandmothers, aunts, and uncles of 86 Samoan androphilic males, known locally as fa'afafine, and 86 Samoan gynephilic males. Reproductive output was elevated in the paternal and maternal line grandmothers, but not aunts or uncles, of fa'afafine. These findings are consistent with the sexual antagonism hypothesis and suggest that male androphilia is associated with elevated reproduction among extended relatives in both the maternal and paternal line. Discussion focuses on how this study, in conjunction with the broader literature, informs various models for the evolution of male androphilia via elevated reproduction on the part of female kin
    corecore