In this passage, Eiseley purposes to explore the mystery of the rapid emergence of the human brain. While still a personal essay, Eiseley writes her philosophical work to anyone willing to listen, not singling anyone out throughout the writing. She begins by illustrating the theory of evolution that is the widely accepted theory of how humans developed; she describes how nature removed our primal instincts, replacing them with newfound brain cells. She then goes into the realization, not only amongst herself but for all readers, that the human brain is what sets them apart from other animals. She shows that how the human brain functions is, though it seems insignificant, miles ahead of the primitive ape. “The clock in the body, in other words,
