AP BIOLOGY

Detailed explanation-1: -If an organism has a vestigial structure (like the pelvis and femur of the whale), that structure likely once had a function in anearly ancestor.

Detailed explanation-2: -Vestigial structures are homologous to fully functioning structures inherited by related lineages. Thus, they provide strong evidence of common ancestry and can help us trace the evolutionary origin of the species with the vestigial structures.

Detailed explanation-3: -Vestigial structures are often homologous to structures that function normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.

Detailed explanation-4: -Overview. Vestigial structures are body parts that have lost their use through evolution. Homologous structures are structures that have a common function and suggest common ancestry. Similar embryos suggest that these animals are related and have common ancestors.

Detailed explanation-5: -A true vestigial organ is indeed an organ that has lost its original structure. It has also lost its function. Individuals possessing a vestigial organ don’t differ in fitness from those without it. The organ is simply a leftover.