Genetic archaeology is taking us into knowledge we never thought we'd find before gene-mapping came about. After all, finding fossils is a rare hit-or-miss event. Harvard evolutionary geneticist David Reich and his team have sequenced the genomes of Neanderthals and Denisovans more clearly and accurately than any past gene-mapping, which help us to compare human DNA over time. When they compared the genomes of those ancient human populations to those of recent humans, they concluded that our homo sapiens...