---
title: "Aquatic ape hypothesis"
chunk: 4/4
source: "https://en.wikipedia.org/wiki/Aquatic_ape_hypothesis"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:37:25.340882+00:00"
instance: "kb-cron"
---

=== Reactions of Hardy and Morgan ===
Alister Hardy was astonished and mortified in 1960 when the national Sunday papers carried banner headlines "Oxford professor says man a sea ape", causing problems with his Oxford colleagues. As he later said to his ex-pupil Desmond Morris, "Of course I then had to write an article to refute this saying no this is just a guess, a rough hypothesis, this isn't a proven fact. And of course we're not related to dolphins."
Elaine Morgan's 1972 book Descent of Woman became an international best-seller, a Book of the Month selection in the United States and was translated into ten languages. The book was praised for its feminism but paleoanthropologists were disappointed with its promotions of the AAH. Morgan removed the feminist critique and left her AAH ideas intact, publishing the book as The Aquatic Ape 10 years later, but it did not garner any more positive reaction from scientists.

== Related academic and independent research ==

=== Wading and bipedalism ===
AAH proponent Algis Kuliukas, performed experiments to measure the comparative energy used when lacking orthograde posture with using fully upright posture. Although it is harder to walk upright with bent knees on land, this difference gradually diminishes as the depth of water increases and is still practical in thigh-high water.
In a critique of the AAH, Henry Gee questioned any link between bipedalism and diet. Gee writes that early humans have been bipedal for 5 million years, but our ancestors' "fondness for seafood" emerged a mere 200,000 years ago.

=== Diet ===

Evidence supports aquatic food consumption in Homo as early as the Pliocene, but its linkage to brain evolution remains controversial. Further, there is no evidence that humans ate fish in significant amounts earlier than tens to hundreds of thousands of years ago. Supporters argue that the avoidance of taphonomic bias is the problem, as most hominin fossils occur in lake-side environments, and the presence of fish remains is therefore not proof of fish consumption. They also claim that the archaeological record of human fishing and coastal settlement is fundamentally deficient due to postglacial sea level rise.
In their 1989 book The Driving Force: Food, Evolution and The Future, Michael Crawford and David Marsh claimed that omega-3 fatty acids were vital for the development of the brain:

A branch of the line of primitive ancestral apes was forced by competition to leave the trees and feed on the seashore. Searching for oysters, mussels, crabs, crayfish and so on they would have spent much of their time in the water and an upright position would have come naturally. Crawford and Marsh opined that the brain size in aquatic mammals is similar to humans, and that other primates and carnivores lost relative brain capacity. Cunnane, Stewart, Crawford, and colleagues published works arguing a correlation between aquatic diet and human brain evolution in their "shore-based diet scenario", acknowledging the Hardy/Morgan's thesis as a foundation work of their model. As evidence, they describe health problems in landlocked communities, such as cretinism in the Alps and goitre in parts of Africa due to salt-derived iodine deficiency, and state that inland habitats cannot naturally meet human iodide requirements.
Biologists Caroline Pond and Dick Colby were highly critical, saying that the work provided "no significant new information that would be of interest to biologists" and that its style was "speculative, theoretical and in many places so imprecise as to be misleading." British palaeontologist Henry Gee, who remarked on how a seafood diet can aid in the development of the human brain, nevertheless criticized AAH because inferring aquatic behavior from body fat and hairlessness patterns is an unjustifiable leap.

=== Diving behavior and performance ===
Professor of animal physiology and experienced scuba and freediver Erika Schagatay researches human diving abilities and oxygen stress. She suggests that such abilities are consistent with selective pressure for underwater foraging during human evolution, and discussed other anatomical traits speculated as diving adaptations by Hardy/Morgan. John Langdon suggested that such traits could be enabled by a human developmental plasticity.

== See also ==

== References ==

== Bibliography ==