The aquatic ape hypothesis won fans and celebrities but never convinced anthropologists
A distinguished marine biologist sat on his idea for thirty years because colleagues advised him to. When Alister Hardy finally proposed in 1960 that human ancestors had waded and dived for shellfish, it caught the public imagination. The scientific community mostly ignored it then, and most still class it as pseudoscience.
Hardy had been mulling the notion since 1930. Only after he was established and knighted for his work in marine biology did he air it publicly, arguing that competition drove a branch of early apes from the trees to tropical shores, where they fished shallow water for shellfish and sea urchins. That lifestyle, he suggested, explained human hairlessness, like that of whales and hippos, our layer of fat under the skin, and even bipedalism, which might have begun as a way to wade. Tool use could have started with rocks for cracking shells.
A German pathologist, Max Westenhöfer, had floated similar ideas in 1942, though he placed the aquatic phase absurdly early, in the Cretaceous, because he did not believe humans were apes. Hardy's version reached a mass audience through Desmond Morris's 1967 bestseller The Naked Ape, and then through the screenwriter Elaine Morgan, whose 1972 book Descent of Woman challenged the prevailing focus on men as hunters. Morgan was still summarising her case for it in 2011.
Critics found little to salvage. The anthropologist John Langdon called it an umbrella hypothesis in 1997, a single pressure invoked to explain many separate traits, and said its apparent simplicity gave it no more explanatory power than assuming water played no special role at all. John Hawks points out that the proposed aquatic period falls in a stretch of the fossil record with no aquatic ancestors, and that the traits in question evolved at wildly different times. Even the fat argument weakened when captive apes with ample food proved to carry similar amounts. The paleontologist Henry Gee has compared its merit to creationism's.
Still, the idea refuses to drown. David Attenborough lent it celebrity endorsement, a 1987 conference in the Netherlands was devoted to it, and it was being promoted again as recently as 2019. A few academics argue the treatment has been harsher than that given to other speculative theories with similar weaknesses.
Source: Aquatic ape hypothesis
