HUMANS could evolve into two sub-species within 100,000 years as social divisions produce a genetic underclass. The mating preferences of the rich, highly educated and well-nourished could ultimately drive their separation into a genetically distinct group that no longer interbreeds with less fortunate human beings, according to British scientist Oliver Curry. Dr Curry, a research associate in the Centre for Philosophy of Natural and Social Science of the London School of Economics, speculated that privileged humans might over tens of thousands of years evolve into a "gracile" subspecies, tall, thin, symmetrical, intelligent and creative. The rest would be shorter and...