Homo Sapiens represents the evolutionary zenith of the genus Homo: we have created scientific and technological miracles in less than 300,000 years. Before us, however, another Homo species lived on Earth for almost two million years. That's the amount of time that it would take for the Roman Empire to rise and fall again about 1,000 times. This species was Homo Erectus. You know: those grotesque cavemen whose greatest technological achievement...