In my opinion, the second main argument in "The Human Drift" is that human wandering across the planet, back and forth, has always been fueled by fear, while motivated by the search of food (as the first argument says). It is a primal fear that, if you don't eat, you will end up in someone else's stomach. Here is a nice excerpt that illustrates this argument: "Dominated by fear, and by their very fear accelerating their development, these early ancestors of ours, suffering hunger-pangs very like the ones we experience to-day, drifted on, hunting and being hunted, eating and being eaten, wandering through thousand-year-long odysseys of screaming primordial savagery, until they left their skeletons in glacial gravels, some of them, and their bone-scratchings in cave-men's lairs."
Life is predictable and lonely
Answer:
They both have their differences in appearance and personality.
