Here's the evolutionary answer, from The Evolution of Man by Wilhelm Boelsche...
"For we find the instructive law on the resemblances of the youthful forms to their ancestors gives us a very satisfactory clue to our original ancestor: the body of the human being in the mother's womb is also, in its first stages, covered with thick woolly hair. Even the face is covered just as we see it to-day in the case of the adult gibbon, and only the inner surfaces of the hands and feet are left free. Evidently these free places were uncovered, even in the ancestor which this human embryo copies for a short time. This Esau-like covering of the human being does not disappear until immediately before birth, and in a few exceptional cases, this covering has even been retained during life. This is the origin of the renowned men with dog faces."
Oh please. That's not "the evolutionary answer"--that's one crank's century-old fever dream. "Bölsche, Wilhelm...had no scientific training but an enthusiasm for Darwinism, positivism, and determinism, which he conceived as the basis for a new harmonious, non-religious, scientific world....Bölsche had not the mental equipment for a profound work on this subject..."