The young girl bent to her task, methodically, rhythmically sweeping away the gravel with the push broom. She worked alone beneath the vast blue sky, amid the sun-drenched expanse of Egyptian desert. The distant band of multicolored cliffs offered relief for the eye, and a soft dry breeze cooled the day.

It was a tedious but relatively pleasant task to sweep the gravel into small piles, leaving the desert floor a smooth sandy blank. The girl’s broom brushed over a small brownish object. Maybe, she thought, it was an ancient crocodile vertebrate, a remnant of the time eons ago when the region was a gravel bar on the banks of a river.

She set aside the broom and crouched on her knees, examining the object more closely. It was circular, evocatively smooth. She took out a paintbrush and delicately began to flick away the soft sandy earth around the object. To her surprise, an eye socket appeared. Her excitement rose, and she continued to brush away the sand, grain by grain. An upper jaw surfaced. She stared awestruck at the object. Peering back at the 14-year-old girl were the lifeless, empty eyes of a skull that had lain undisturbed for 30 million years. That small, perfect cranium had held the brain of a distant ancestor of humans – a feisty, furry creature that possessed the faintest spark of an intelligence that would blossom over thousands of generations to bring its progeny to dominate the Earth.

The elated girl ran for help, returning with a bearded, turbaned anthropologist who, with practiced skill, extricated the skull from its resting place and turned it over admiringly in his fingers. Yes, he confirmed, it was the front of a skull of the primitive primate Aegyptopithecus, only the fourth such face ever discovered. He placed it gently in his pocket and cautioned her to keep their secret. They would triumphantly reveal her remarkable discovery that evening, creating great wonder in the expedition’s scientists. He smiled and congratulated her and returned to his own work. The girl stood for a moment, overcome by the import of her find. Then she sat down on the smooth desert floor and cried....