The father and son team of Brodie and Brodie track down the predator able to stomach a mysteriously hyper-toxic newt, an example of an evolutionary arms race in action. From Evolution: "Evolutionary Arms Race." [5:27]

Eastern hellbenders live throughout the Appalachian region in the United States. Their ancestors have been on Earth for around 160 million years, but in the last several decades their numbers have dropped dangerously in several states,...

Go into the woods with Mitch, a research scientist, to look for and tag red-backed salamanders. [4:38]