Abstract:
Masturbation occurs throughout the animal kingdom. At first glance, however, the fitness benefits of this self-directed behaviour are unclear. Regardless, several drivers have been proposed. Non-functional hypotheses posit that masturbation is either a pathology, or a byproduct of high underlying sexual arousal, whereas functional hypotheses argue an adaptive benefit. The Postcopulatory Selection Hypothesis states that masturbation aids the chances of fertilization, while the Pathogen Avoidance Hypothesis states that masturbation helps reduce host infection by flushing pathogens from the genital tract. Here, we present comprehensive new data documenting masturbation across the primate order and use these, in conjunction with phylogenetic comparative methods, to reconstruct the evolutionary pathways and correlates of masturbation. We find that masturbation is an ancient trait within the primate order, becoming a more common aspect of the haplorrhine behavioural repertoire after the split from tarsiers. Our analyses provide support for both the Postcopulatory Selection and Pathogen Avoidance Hypotheses in male primates, suggesting that masturbation may be an adaptive trait, functioning at a macroevolutionary scale.
摘要:
手淫发生在整个动物界。乍一看,然而,这种自我导向行为的健身益处尚不清楚.无论如何,已经提出了几个驱动程序。非功能性假设认为手淫要么是一种病理,或者高潜在性唤起的副产品,而功能假设则认为是适应性利益。交配后选择假说指出,手淫有助于受精的机会,而病原体回避假说指出,手淫有助于通过冲洗生殖道的病原体来减少宿主感染。这里,我们提供全面的新数据,记录整个灵长类动物的手淫,并使用这些,结合系统发育比较方法,重建自慰的进化途径和相关因素。我们发现手淫是灵长类动物秩序中的一种古老特征,从眼镜猴分裂后,成为单纯性出血行为的一个更常见的方面。我们的分析为雄性灵长类动物的交配后选择和病原体回避假说提供了支持,表明手淫可能是一种适应性特征,在宏观进化的尺度上运作。