AP BIOLOGY

Detailed explanation-1: -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-2: -Molecular. There are also vestigial molecular structures in humans, which are no longer in use but may indicate common ancestry with other species.

Detailed explanation-3: -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-4: -Some vestigial structures persist due to limitations in development, such that complete loss of the structure could not occur without major alterations of the organism’s developmental pattern, and such alterations would likely produce numerous negative side-effects.

Detailed explanation-5: -Structures like the human tail bone are called vestigial structures. Evolution has reduced their size because the structures are no longer used. The human appendix is another example of a vestigial structure.