pissvortex:pissvortex: chimp balls You are all but pawns on my chessboard Excellent illustration of
pissvortex:pissvortex: chimp balls You are all but pawns on my chessboard Excellent illustration of the consequences of sexual selection. In polygynous primates such as gorillas, males fight with each other to take control of a certain number of females, to which they have exclusive access. Most reproductive competition among males occurs before mating. As a consequence, male gorillas have evolved massive chests and arms to fight (non-lethally) with their peers, while their genitals became comparatively insignificant (effectively, the bare minimum necessary to fertilize their partners, whom nobody else will approach).At the opposite extreme, in the promiscuous chimpanzees (and moreso in bonobos), multiple males will mate with each female. While there are dominance hierarchies in each sex, they don’t involve exclusive access to partners. Most reproductive competition among males occurs after mating. As a consequence, male chimpanzees are not much larger than female, but they did evolve enormous testicles to produce more sperm than their peers, and long but thin penes to deliver it as close to the cervix as possible.(source: Alan Dixson, Sexual Selection and the Origins of Human Mating Systems, Oxford University Press, 2009, p. 27; the source makes the point that this model is a simplification, and reality, as always, is More Complicated Than That) -- source link
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