One whole endogenous retrovirus genome -- and bits of 17 others -- were spotted in a study of 2,500 human genomes... Nineteen new pieces of DNA -- left by viruses that first infected our ancestors hundreds of thousands of years ago -- have just been found, lurking between our own genes. And one stretch of newfound DNA, found in about 50 of the 2,500 people studied, contains an intact, full genetic recipe for an entire virus, say the scientists who published their findings today in the Proceedings of the National Academy of Sciences. Whether or not it can replicate, or...