(Echo) Using genes to plot the Mammalian Family Tree

Don't blame the dinosaurs

Scientists can compare the DNA of different creatures to get an idea of how long ago they had a common ancestor. This article explains how some scientists have compared the genes of mammalian species to figure out that mammals were already very deverse long before the dinosaurs went extinct. This is fascinating stuff-- a fascinating discovery and a fascinating way to have discovered it. People are pretty smart!