The Parsimonious Human Body Factory (PaHuB factory) was probably located on Bioko Island

Allan Krill

Boeing airplanes have crashed a few places in the world during the past century. Before crashing, those planes may have been modified in different cities, giving them new seats and paint jobs. But the planes really evolved and were produced at the Boeing factory and airport in Seattle. It takes a dedicated location with all the right conditions and materials to produce a commercial airplane. 

To evolve a human body from a chimpanzee-like ancestor, it must have required special materials (especially marine omega-3 fatty acids for exceptional brain evolution) and safe, reproductively-isolated conditions over a long time span. Humans are unique primates: they are bipedal, have bald bodies, large brains, protruding noses, blubber, descended larynxes, multi-pyramidal kidneys, and many other unique features that can best be explained by semiaquatic evolution.

I think that human bodies only evolved on the shores of Bioko Island, and only over the past 6 million years or so. Read this published article for more details. Bioko is an isolated volcanic island, near the places in Africa where chimpanzees and gorillas evolved. None of them left a single fossil, because the ground is wet and warm. All the bones decayed. No mammal fossils of any kind are known from those places.

Bioko Island is 32 kilometers from mainland Africa. 
The first apes to accidentally raft from Africa to Bioko could not swim. Their descendants might have been isolated on the island for millions of years. Bioko Island probably had no large predators or African viruses for millions of years. Its 150 kilometer coastline probably had an enormous supply of omega-3-rich sea-turtle eggs, as it does today. 

Mainland Africa is visible from Bioko, and it is a swimmable distance for an aquatic ape. (The water is warm.) After evolving bodies on Bioko, some of the unique semiaquatic primates could have dispersed to mainland Africa and other continents. Their bodies were slightly modified in those places, and only a few crashed in ways that could leave fossils.

If Homo erectus really existed, it was probably a late-model (produced about 1.5 million years ago) that walked from Bioko to Africa when sea level was temporarily low, during one of the glacial maxima. Erectus had a big enough brain to invent the clothing, weapons, and tools that were needed to survive as a vulnerable naked ape in Africa. (Naked humans with no clothing, tools, weapons, or fire could easily survive on Bioko beaches today. There no large predators, most days are cloudy, and the nights are never cold. Sea-turtle eggs from the hundreds of nests on beaches would be the main diet.)

Erectus is thought to have dispersed widely, leaving bones and chipped stones in East Africa, Europe, Java, and China. Neanderthals and Denisovans are fully evolved humans. They probably also came from the same PaHuB factory, with some minor modifications elsewhere.

DNA provides a sort of serial number, that can be read on living chimpanzees and humans. It is now becoming possible to find some of these serial numbers on crash fragments (fossils.) It may eventually be possible to determine if humans actually evolved on Bioko Island. An example of such evidence would be if all living humans carry an endogenous retrovirus (ERV) that is otherwise only found in animals living on Bioko.