The story of human evolution I heard in school never seemed quite right. It's easy to see how similar we are to chimps but much harder to explain the glaring differences. We look so different from other apes that it's easy to think we didn't evolve the same way. The conventional story is that we adapted to living on the plains instead of the trees and that explains the differences but baboons live on the plains and they are even more different from us than chimps. For years I figured that there must be a better explanation that had not yet been found.
In the late sixties I read "The Naked Ape" by Desmond Morris. It trotted out the same tired story with some embellishments. On one page it described an alternate theory that made instant sense of the differences between chimps and humans but there was no elaboration of it.
Years later I read "The Descent of Woman" by Elaine Morgan (widely available in paperback). She had the same experience I did when reading Morris but developed the theory into a captivating book with a feminist flavor. She continued the development with "The Aquatic Ape" and "The Scars of Evolution".
Radical changes in physiology are caused by radical changes in environment. Many features that make us so different from the other apes are found in marine mammals but not in land mammals. We are descended from apes that started to adapt to life in the sea then returned to life on land.
Human features common in marine mammals include:
People love beaches because we evolved there.
The earliest human bones are found in the Great Rift Valley in Africa which leads up to mountains in Ethiopia. The sea level rose, isolating these mountains and forcing the apes there to adapt to living off, and partially in, the ocean. When the sea level fell early humans walked into Africa and then the rest of the world.
The puzzle is solved; read Elaine Morgan's books for details.