The theory seeks to explain human traits such as hairlessness, salty tears, fat tissue, bipedalism and sweat glands. It also explains why human body is streamlined and why apes quickly drown when put in water while humans do not.
The German biologist Max Westenhõfer was perhaps the first to publish the idea in an evolutionary context. Using the principle of convergent evolution, it says that life in an aquatic environment explains these features, and that a transition from ape to hominid in a non-aquatic environment cannot.
The theory is somewhat out of favor because several key pieces of evidence fail to support the theory. For example, hairlessness, while found in several aquatic mammals, is not indicative of aquatic mammals (see aardvarks and rhinoceros).
- ↑ The most widely held theory, still taught in schools and universities, is that we are descended from apes which moved out of the forests onto the grasslands of the open savannah. The distinctly human features are thus supposed to be adaptations to a savannah environment. The Aquatic Ape Theory--Elaine Morgan