The Aquatic Ape Hypothesis

The aquatic ape hypothesis (AAH) is an alternative explanation of human evolution which theorizes that the common ancestors of modern humans spent a period of time adapting to life in a partially-aquatic environment. The theory is based on differences between humans and great apes, and apparent similarities between humans and some aquatic mammals. First proposed in 1942 and expanded in 1960, its greatest proponent has been the writer Elaine Morgan, who has spent more than forty years discussing the AAH.
While it is uncontroversial that both H. neanderthalensis and early H. sapiens were better suited to aquatic environments than other great apes,^[1][2] and there have been theories suggesting protohumans underwent some adaptations due to interaction with water^[3] the sort of radical specialization posited by the AAH has not been accepted within the scientific community as a valid explanation for human divergence from related primates. It has been criticized for possessing a variety of theoretical problems, for lacking evidentiary support, and due to alternative explanations for many of the observations suggested to support the theory. Morgan and others have also suggested that her status as an academic outsider has hindered acceptance of the theory.