This is a very interesting theory. The author, a geneticist, thinks it is possible that we evolved from the mating of a primate with a non-primate, combined with some generations of back-crossing, i.e., the mating of the offspring with one of the parental types. He says that in order to identify the non-primate partner, a geneticist would make a list of characteristics which do not appear in any primates, then look for a candidate mammal that matches those characteristics. He presents some stunning evidence, it seems to me, but then I do not know enough about genetics to know what questions to ask or what objections to raise.
Judge for yourself.