The existence of similar bone arrangements in the forelimbs of humans, bats, whales and horses is used as evidence for evolution. This type of evidence is referred to as

Homologous structures are anatomical features that share a common evolutionary origin but may differ in function across different species. The similar bone arrangement (humerus, radius, ulna, carpals, metacarpals and phalanges) in the forelimbs of humans, bats, whales and horses indicates descent from a common ancestor. Analogous structures, by contrast, perform similar functions but have different evolutionary origins.