This evolutionary tree includes baboons. Both baboons and humans went from the trees to the ground. The baboon shows a normal evolution, whereas the human shows a weird evolution. I think that is like the ground-dwelling iguana on Galapagos. The tree-dwelling iguana rafted from South America to Galapagos, and was trapped there, with no trees to live in. It adopted a marine habitat, and its body changed dramatically like the human body changed. Then it became ground-dwelling, with a weird body that shows its earlier marine habitat. Read about this iguana on Wikipedia.
https://en.wikipedia.org/wiki/Marine_iguana
https://en.wikipedia.org/wiki/Galapagos_land_iguana

http://AquaticApe.net

And here is one more.

Clothes and tools were needed before the human species could survive most places in the world.
Image where in Africa, or elsewhere in the world, a naked human family without tools could survive for a year? 
It was only the large brain that allowed the human body to function in most places. But I think a naked family could have survived on Bioko. 

Here is another:

Here is another evolutionary tree. 
The aquatic ape theory is very simple (parsimonious).
Like the evolution from arboreal to marine to land iguana on Galapagos.

Speciation requires reproductive isolation, for which there can be many causes. Sometimes this is by physical separation, but there are many other possibilities. Gorillas and chimpanzees had an arboreal ancestor in the forests of central western Africa. But gorillas chose a different diet than chimpanzee, so they diverged within the same area. Here is an explanation, from p. 13 of the book: Chimpanzees and human evolution. 

The fundamental difference between chimpanzee and gorilla diets is that gorillas, because of their large bodies and guts, can subsist on much lower quality food. Both apes prefer to eat fruit when it is available. However, comparisons in the same forests show that, as fruit becomes rarer, gorillas fall back on increasing amounts of pith, leaves, and woody stems, while chimpanzees continue to search for higher-quality food (reviewed in Wrangham 2006; Harcourt and Stewart 2007a).

Here is another evolutionary tree, where I mention the areas and foods of speciation.