Specifically, the the multiple back-crossing an archaic Chimpanzee (primate) male who had a high level of plasticity in the sexual response. When he had become bored of fucking the females, children, and any other smaller males, lizards, and perhaps birds or fish, he found a very special pig. And that pig's offspring was the alpha generation that became the alpha male raping monkey's sex toy. Serial rape and multiple litters later, the nascent strangely-featured, mostly primate, partly porcine new mammalian line was born.

He immediately set out to continue the raping ways of his sire, perhaps raping and killing him, and then moved on, to take over as the alpha male in a troupe of chimps that eventually evolved to become us.

>In his research into human origins, McCarthy employed the same methods he had seen other biologists use in identifying unknown hybrids. So he first made the assumption, based on chimpanzees being our closest living relative, that the chimpanzee would likely have been one of the two parents in the cross. He then made a list of all the characteristics that distinguish us from the chimpanzees. That list he realized would describe the traits of the second parent, if it still existed.

>Among them: largely hairless skin, a comparable layer of fat beneath the skin, thermoregulatory sweating, light-colored eyes, a protruding rubbery (cartilaginous) nose, vocal cords, heavy eyelashes, humanlike molars, a short pelvis, a curved sacrum with short dorsal spines, similarities in the structure of the kidneys and other internal organs, tiny hooves (called ungual tuberosities) just beneath the skin on the tips of our fingers and toes, and a wide variety of other features.