AP Photo

Pirates used to say that “dead men tell no tales.” Of course, the buccaneers had never heard of the polymerase chain reaction. Dead men turn out to be loaded with information if you can get your hands on them — or better yet, on small preserved pieces.

The genomics revolution, two decades old, has given biological researchers an astonishing array of tools, both physical and computational, to extract information from once-living tissue. Perhaps the most spectacular example was the discovery of enough remnant DNA in Neanderthal bones to allow scientists to conclude that those extinct hominids once interbred with modern humans.