[1] He took his first degree from the University of Cape Town in 1958 before studying for his PhD at Peterhouse, Cambridge which he completed in 1969.

Working with Richard Leakey, he was co-director of the East African Koobi Fora project.

He was survived by his twin brother, Rhys Isaac, an historian, based at La Trobe University.

[1] In the early 1970s Isaac published on the effect of social networks, gathering, meat eating and other factors on human evolution, and proposed a series of models to examine how groups of humans in the paleolithic would have engaged in acquiring the necessities of life, and interacting with each other.

Isaac's models focused on a "home base" and the importance of sexual division of labor on hominid social organization.