" New experiments reveal a multibillion-year history filled with cooperation, repurposing, competition, theft, and war. And that is just what happens inside DNA itself. With viruses continually infecting it, and its own parts at war with one another, the genome within each animal cell roils as it does its work in generation after generation. "

― Neil Shubin , Some Assembly Required: Decoding Four Billion Years of Life, from Ancient Fossils to DNA