Sex, Time, and Power

Sex endows the individual with a dumb and powerful instinct, which carries his body and soul toward another; makes it one of the dearest employments of his life to select and pursue a companion, and joins to possession the keenest pleasure, to rivalry the fiercest rage, and to solitude an eternal melancholy. What more could be needed to suffuse the world with the deepest meaning and beauty?
George Santayana
The reconstruction of evolutionary history is better regarded as a game than as a science, evolutionary hypotheses should be stated with varying degrees of confidence always keeping in mind that certainty cannot be achieved.
Sherwood Washburn
She died an agonizingly slow and painful death. She was not accorded funerary rites, nor was her corpse laid to rest in a grave. Her remains constitute but a sliver of debris a disconnected tooth here, a chip of a fossilized bone there, fragments lost in the strata of bygone ages. At the time of her death, she represented the latest in a line of primates called "hominids" that had begun their evolutionary trial run several million years earlier. If paleontologists ever find her final resting place, we should erect a memorial on the spot in recognition that she did not die in vain. An appropriate name for her marker would be "The Tomb of the Unknown Mother." Her passing heralded the birth throes of a new species.

Imagine that a group of intergalactic anthropologists had been observing these primates from the beginning. When Unknown Mother died, the visitors would have exchanged knowing looks, because they could plainly see that her fate was foredoomed. The hominid line from which she arose had split away from other primates by developing two adaptations destined to collide. Hominids were the only primates to depend on a new means of moving about that required only two limbs instead of four. An upright stance allowed them to clamber down from the trees and seek a living first on the forest floor and later on the open savanna. Because their erect posture greatly increased the possibility that the first creature to stride would end up as "cat food," they needed a crucial second adaptation. Since they could not outrun or outfight predators, they required an enlarged brain capable of outwitting those creatures intent on devouring them.

During the last two and half million years, the hominid brain had tripled in size but the opening in the pelvic girdle through which this rapidly enlarging brain had to pass at birth did not keep pace. These two adaptations two-leggedness and watermelon-sized heads were clearly incompatible.