Sexual Evolution

In this year of Darwin festing, it seems timely to consider the evolution of one of our post-Fall delights – namely sex.

Professor Steve Jones, in his wonderfully witty book, Almost Like a Whale, poses the interesting question: Why do men have such large genitals, especially as  Homo Erectus does not signal his genetic excellence by means of his penis; few, indeed, get to see it – until the last minute. In the days before trousers, it may well have evolved, like the peacock’s tail, to signal fitness and genetic health. But the peacock’s greatest asset carries a price – if it is too large, he succumbs to a predator and doesn’t get to benefit from his asset much. Proud men in some tribes in New Guinea wear an extension of about a foot, without which, they feel naked; and one may well ask whether they are living in La La land or do they know something the rest of you do not? Could it be that they hope the flesh will get the message and grow accordingly – or do they fear such a virile member could easily be severed by a jealous rival – perish the thought!

Homo erectus’s  predecessors, on the other hand, manage very well with penises the size of a thumb. Gorillas and chimpanzees, especially bonobo chimps, seem quite content with their lot  – some male chimps manage hundreds of sexual encounters with dozens of females every year, and no one pursues them for financial support. So why the evolution of the great big one you take such pride in?

Could it be the emerging clitoris that demanded more attention? Or did the female simply adapt to unnecessary size? Females, undoubtedly play a part in evolutionary adaptation The female red-backed spider, for instance, insists on long foreplay or else the male gets eaten after delivering sperm, so the male has learned to vibrate the web in which she is sitting, and also to tickle her abdomen with his palpae. If she is pleased with him, she lets him live. Long live the male who learns and adapts.

And, boys, learn from the bluegill sunfish who has to deal with smaller males invading his hard-won territory, into which he has enticed his chosen female. These annoying little fellows emit semen, which admittedly, like any discount goods, carries certain disadvantages (no guarantee or impressive wrapper) but is nonetheless going to make its mark with some females. And when these cheats grow too big to sneak in, they take on a female guise which enables them to get into the place they most want to be (their only fear being that the Lord of the Manor might mistake them for eager females seeking his charms). Be grateful, boys, for your relatively easy life that enables you to focus on simply pleasing your adoring partner.  

But seriously: how did this urge to inseminate the female, at considerable risk, become the delightful adventure that the human male and female share?


By Jenny, 78, mother of TBW founder Julia who has a life long interest in science and a 30 year interest in younger men… [which is still going strong!]

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