Habitat:

The model predicts that north-eastern rift valley habitat, being prone to major volcanic events, would occasionally almost self-destruct. 

On these occasions a wave of surviving hominids would be forced out from the location to find alternative habitats.

I predict that this is what caused the radiation of early hominids and the factor that formed two major groups the robust and gracile Australopiths. The idea is that apes forced away from their traditional gallery forest habitat would be forced to find alternative food sources and some, the megadonts, would have to rely on unusual food sources like tubers. Hence Australopithecus Robustus and later Australopithecus Boisei evolved such massive masticatory structures. The model proposes that some of these apes are the ancestors of gorilla. The gracile forms included some that would become the ancestors of Pan and others who would be part of Homo phylogeny.

Every time a volcanic event occurred I would predict that a "Out of Afar" diaspora followed. But each time, after several thousand years, the Afar region and rift valley lakes and rivers would recover and become re-populated again. The robust forms found a completely new wetland niche, living on plentiful waterside roots and shoots and consequently jaw & teeth morphology would get larger in size as the generations passed by.

My model predicts that while all of this is going on, a much smaller number of the original swamp apes were still 'marooned' on the coasts of the Danakil Gulf. As time goes by, these hominids are gradually becoming adapted to a marine environment and, perhaps due to an adaptation to a coastal mangrove forest habitat, where babies were prone to falling into the water, the process of encephalisation gradually took place. Their swimming and diving skills are advancing as was their salt-tolerance as Africa got drier and the leaching of the gulf reduced. These are the ancestors of a type of theoretical hominid I call the seasiders, Homo maritimus.