The Aquatic, Groupish, Warlike Ape

Darwin’s Dangerous Idea has been one of the most influential books in my thinking and in my life. One of the most memorable examples in that book was Max Westenhoefer and the Alister Hardy’s “Aquatic Ape Hypothesis”: the idea that human beings are evolved for living on the seashore. The idea of being an “aquatic ape” resonates with me because I have always loved swimming and I love seeing ocean waves crash against a beach.  Curtis Marean’s article “The Most Invasive Species of All” in the August 2015 issue of Scientific American touched on the Aquatic Ape Hypothesis. He writes on page 36:

Genetic and archaeological evidence suggests that H. sapiens underwent a population decline shortly after it originated, thanks to a global cooling phase that lasted from around 195,000 to 125,000 years ago. Seaside environments provided a dietary refuge for H. sapiens during the harsh glacial cycles that made edible plants and animals hard to find in inland ecosystems and were thus crucial to the survival of our species. These marine coastal resources also provided a reason for war. Recent experiments on the southern coast of Africa, led by Jan De Vynck of Nelson Mandela Metropolitan University in South Africa, show that shellfish beds can be extremely productive, yielding up to 4,500 calories per hour of foraging. My hypothesis, in essens, is that coastal foods were a dense, predictable and valuable food resource. As such, they triggered high levels of territorialisty among humans, and that territoriality led to intergroup conflict. This regular fighting between groups provided conditions that selected for prosocial behaviors within groups–working together to defend the shellfish beds and thereby maintain exclusive access to this precious resource–which subsequently spread throughout the population.