The tree of life is a diagram used in evolutionary biology to organize life into categories and to classify different species. In this case, tuna, turtles, and chimpanzees and humans are species that can be grouped in the animal category, within the vertebrates group (chordate phylum), being it the most inclusive level at which all these species belong.
Each branch point on the cladogram represents where species split off into new ones. The node represents the last point at which 2 new species shared a common ancestor.
