Discussions of human origins invariably rest on rather shaky foundations. The fossil record – such as it is – has huge gaps, isn’t a random sample of the fauna, and only preserves the gross features of anatomy evident in bones. So it’s hardly surprising that a range of theories have been proposed to explain the division between apes and humans.

The aquatic ape hypothesis is one such. It has some supporting evidence – or, rather, it isn’t definitively contradicted by the evidence that there is. In this it falls into the common evidential trap of turning a lack of evidence against into prima facie evidence for: the classic pseudoscience bait-and-switch.

It’s possible to pose the theory at several strengths. The strongest, that hominids went through an aquatic phase long enough to give rise to evolutionary adaptations that haven’t been wholly lost, seems unsupported; the weakest, that hominids spent time near water and waded in order to access rich food supplies, seems unobjectionable.I’m unconvinced there’s much else to it, or indeed that there ever could be given the limitations of the evidence available.

1/5. Finished Thursday 10 May, 2018.

(Originally published on Goodreads.)