The evolution of loss

Fascinating study out this week that has been making rounds in the press. This is probably because it allows editors to use the word 'penis' in their headlines. (It's the 21st century — anything for some Google juice, right?). This is a bit of a shame, as, in the pursuit of clicks, I think it distracts from the elegance of the study, and some of its broader implications.

I wrote about it for COSMOS Magazine (and we used the word 'brain' before 'penis'!). In brief, the paper focuses on two genetic deletions in human evolutionary history. One removed a neural regulator, and this loss is correlated with the rapid expansion of the human brain. The other eliminated the keratin 'spine' of the human penis. In primates, the loss of a penile spine is often correlated with monogamous behaviour.

First, that bodily morphology can be intimately tied to our common behavioural decisions (e.g. penile spines and monogamy). And also, that the removal of one sequence (i.e. a neural regulator) can radically alter the intellect and social atmosphere of an entire species. In other words, that small evolutionary loss can lead to substantial social and behavioural gain.

It is, I think, quite a beautiful conclusion. Put rather crudely: that evolutionary loss may have helped our species evolve certain fundamental characteristics of being human — long-term partnerships, complex cognitive ability and, perhaps, monogamous love.

As always, however, 'perhaps' is the operative word.

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News and notes:

• One of the best posts on the story I've seen so far is by Ed Yong. Honorary mention to Eric Michael Johnson (much longer, much more thorough).

• For you UK folk, I'm helping organize SciBarCamb (SciBarCamp Cambridge) April 8 & 9. Keep it free - will be a blast.