What human part is a bat's wing homologous to?

A bat's wing is homologous to the human hand. Both structures share a common anatomical origin, as they are derived from the same type of limb bone structure. In bats, the elongated fingers support the wing membrane, while in humans, the fingers are shorter and adapted for grasping. This evolutionary relationship highlights the concept of divergent evolution, where different species develop distinct forms from a common ancestor.