Answer:
"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."
Explanation:
This text is about the migratory movement of men around the globe overtime, usually called drifts. Therefore, the passage explains the message of the author very precisely: men have walked from place to place, to runaway from hunger and fear of predators. Even today we experience a wild migratory movement, like the refugees, that runaway from their home country to survive from pain and hunger.
