ANATOMY

Detailed explanation-1: -Structures that have different mature forms but develop from the same embryonic tissues are called homologous structures. Similarities and differences in homologous structures help biologists group animals according to how recently they last shared a common ancestor.

Detailed explanation-2: -Homologous structures are those from organisms that share a common ancestor. (Ref. 1) The similarity in the anatomical features can be used to support conjectures regarding their evolutionary histories.

Detailed explanation-3: -Homologous structures share a similar embryonic origin; analogous organs have a similar function. For example, the bones in the front flipper of a whale are homologous to the bones in the human arm. These structures are not analogous. The wings of a butterfly and the wings of a bird are analogous but not homologous.

Detailed explanation-4: -Homologous structures in different species may have slightly or very different functions. In order to be considered homologous, anatomical structures must develop from the same embryonic tissue.

Detailed explanation-5: -Homologous structures share an ancestor but serve a different function but analogous structures serve a similar function but do not share an ancestor. Vestigial structures are traits that our ancestors needed but no longer serve a purpose in our environment.