There is nothing unusual about primates exploiting aquatic resources for food. Wading bipedally in shallow water and even diving underwater for aquatic plants or shellfish in freshwater and in marine environments has been observed in many monkeys and apes and, of course, is common in primitive human populations. So its certainly not a question as to whether such bipedal aquatic feeding behavior in humans and other primates is possible.

The question is, is there any evidence that a primate species actually became– specialized– in such aquatic feeding behavior for an extensive period of evolutionary time and whether its possible humans could be descended from such primates.

The aquatic ape hypothesis was first conceived by Oxford marine biologist, Sir Alister Hardy, back in the 1920s. But he didn’t reveal his hypothesis to the public until 1960 during a lecture and then in an article in the journal, New Scientist.

Elaine Morgan first encountered the hypothesis after she read a synopsis of it in the Desmond Morris book, the Naked Ape. Then she wrote about it in her own book, the Descent of Woman in the early 1970s.

Basically, Hardy’s argument was that humans became bipeds and developed a thick subcutaneous fat because they needed to wade into shallow water in order to get access to shellfish.

I should note that aquatic wading is also one of the leading hypotheses for the origin of bipedalism in archosaurs (dinosaurs, birds, and crocodilians)

I think its pretty obvious that Oreopithecus evolved its bipedalism as a wading adaptation for exploiting aquatic plants during its 2 million years of isolation on the ancient Mediterranean island of Tuscany-Sardinia.

The lobulated medulla of the human kidney strongly suggest that humans were once specialized in consuming foods with an extremely high salt content. Since the African continent tends to be deficient in food resources with high levels of salt, human ancestors obviously evolved such kidneys along a marine coastline– probably an island, IMO.

Marcel F. Williams