HUMAN NATURE DESCENDS FROM THE STRUGGLE FOR FITNESS. This view of man was born in October 1838, when Charles Darwin read Thomas Malthus's treatise on the perils of overpopulation upon which he framed his theory of natural selection as the "survival of the fittest." When Darwin turned his attention to the evolution of humans in The Descent of Man, and Selection in Relation to Sex, he introduced the crucial role of sexual selection. Ape Mind, Old Mind, New Mind: Emotional Fossils and the Evolution of the Human Spirit reinterprets the known facts about human evolution in light of Darwin's other evolutionary mechanism. The remarkable aspect of Darwin's evolution by sexual selection is that it is driven merely by the desire for a trait--in this case, the desire for justice. What gave sexual selection the creative power to launch and then sustain our hominin tribe was, and still is, the additive effect of both the desire for justice and the desire to be just, both passed down together tightly engaged in the pioneering of rightness and wrongness. Author John Wylie, M.D. focuses on the role of natural selection in the conversion from submission and dominance in apes to obedience and authority in humans. Under the protective shield of justice, groups of mated pair-bonds could evolve the productive benefits of coordinating and dividing the labor of child care and food gathering. At the end of the day, those groupings of relationships that "believed" in the rules of this organic social structure would be naturally selected. The procreative benefits to individuals within a given group immersed in this obedience-authority system would exceed any benefits of pursuing their own dominance. The will to dominate in the ape mind transformed into the authority of justice in the early human (old) mind by migrating from individuals to dwelling within the thin ether of relationships between individuals; no one could see it, but all could feel it. This invisible but biologically based will could be said to possesses intentions, i.e.: a spirit . . . the human spirit. Human bonds animated by this still evolving spirit ultimately would become more powerful than those of blood, tribe or country.