You may have seen a family tree, a visual representation of how individuals are related. But what about entire species? We can use DNA sequences to infer how closely related species are to each other and to build diagrams of their relationships called phylogenetic trees.

Three panels: the first is a phylogenetic tree of an orangutan, gorilla, chimpanzee, bonobo, and human; the second, a phylogenetic tree of whales, hippos, ruminantia, pigs, and camels; the third, three DNA sequences.
Examples of DNA sequences and phylogenetic trees.