According to this morning's 'i', a group of scientists, academics and medics are coming together today to discuss the Aquatic Ape theory of human evolution. It's a theory that has been marginalised and ignored over the years, and the last time it was discussed seriously was at a conference in 1992.
In spite of this, it's a theory that just won't go away.
When I was studying archaeology at university, I came across a book called The Descent of Woman, by Elaine Morgan, which set out the Aquatic Ape theory, and when I read it I saw that it made a lot of sense.
The standard theory at the time, and one which still carried a lot of weight today, was that the apes came down from the trees and spread out across the African savannah, where Man the Mighty Hunter learned to run fast on two legs and chuck spears at antelopes.
This is all very well, but what were the apes doing while they were learning to run fast? And how did they get the hand/eye co-ordination to be able to chuck spears at antelopes? I knew about Lucy, the little hominid who could walk upright - but certainly not run fast, since her hips weren't that well adapted at that point. As Elaine Morgan points out, if our hominid ancestors who looked like Lucy were venturing out onto the savannah, they were becoming a leopard's dinner rather than Man the Mighty Hunter.
It's a lot easier to walk upright if you have some support, such as wading in water, and a reason to go into the water, such as lots of slow-moving (or stationary) food, like shellfish or crabs. Proboscis monkeys do this in the swamps today. We are the only great ape to enjoy swimming. We have subcutaneous fat and very little body hair, like marine mammals. We cry, like marine mammals, and our larynx is adapted so that we can hold our breaths - and this change meant that we could develop language, unlike any other great ape.
And when we waded out of the swamps, we were fully bipedal, and had bigger brains (from eating all those fish) and were able to go out across the savannah to chuck spears at antelopes.
Elaine Morgan was writing in 1972, and though she was popularising a theory first posited by Sir Alister Hardy, she herself wasn't a scientist. She was a good writer, though, and she took each of the points where we differ from gorillas and chimps one by one, and gave a sensible explanation - which some of the standard theories didn't even attempt. Sir Alister was intending to write a more scholarly version of the theory, but in the end it never happened.
Sir David Attenborough will be at the conference that started today, and if he's interested enough to take it seriously, maybe there is something in it after all?