For years, evolution's critics picked on supposed gaps in the historical record--missing links between different forms or species in biologists' evolutionary lineages. Evolutionary leaps, say from dinosaurs to birds, are inconceivable without intermediates, so the reasoning went. Finding key fossils is no easy matter, but creationists interpreted the absence of evidence as evidence of absence--no links, no evolution, only supernatural design.
Paleontologists were patient, though. They predicted that the feathers so important in bird flight were probably co-opted from another function, most likely thermal insulation. If that's true, scientists should eventually find fossils of feathered flightless animals. Their patience paid off over the past few years as China's Liaoning province yielded spectacular specimens of feathered dinosaurs.1 And birds aren't alone. The same painstaking process of scientific discovery is illuminating the evolutionary history of flowering plants, whales, snakes, and--dare we say it--humans.
But never say die--if cats have...