So here’s the answer to the central question…
Big brains are related to strong social bonds, high levels of intelligence, intense parenting, long periods of learning, and ability to deal with volatile environments. Exactly which one was the initial force driving the human brain expansion is unknown. In comparison to the great apes, early hominids lived in more open and dry areas, which made it difficult to escape from predators and find water. Thus, the brain size expansion may be related to the ability to cope with volatile environments, as some people believe. But, there is no definite answer yet.
Evolutionary biologist Jianzhi Zhang, The University of Michigan in Ann Arbor. Detail from his study in the journal Genetics, December 2003
Often referred to as the Great Apes, the Pongidae include the orang-utans (Pongo pygmaeus), chimpanzee (Pan troglodytes), the bonobo (Pan paniscus), the gorilla (Gorilla gorilla) and humans (Homo sapiens). Continue reading 2. Everything you never thought you needed to know about the Gorilla
It was the early nineties and I have now have no memory what I was doing but I definitely heard it on BBC Radio 4; the reason why gorillas have a large brain*. Not the kind of question I came across in my line of work at the time, but suddenly how relevant it seemed. Continue reading Pre-amble, a Gorilla Gait