AP BIOLOGY

Detailed explanation-1: -Similarities in embryos are likely to be evidence of common ancestry. All vertebrate embryos, for example, have gill slits and tails. All of the embryos in Figure 9.3. 4, except for fish, lose their gill slits by adulthood, and some of them also lose their tail.

Detailed explanation-2: -Embryos of different species can have similarities that are not visible when the organisms are fully formed. Many of these similarities are homologous features. These features provide evidence that the species are related through evolution. embryos have homologous structures called pharyngeal arches, or gill arches.

Detailed explanation-3: -Embryology Evolution Examples Examples found in comparative anatomy include the forelimbs of humans and the flippers of a whale, which supports the idea of common descent. Although a human arm and bat wing look different, the process of embryonic development is similar.

Detailed explanation-4: -Comparative embryology reveals homologies which form during development but may later disappear. All vertebrate embryos develop tails, though adult humans retain only the coccyx. All vertebrate embryos show gill slits, though these develop into gill openings only in fish and larval amphibians.

Detailed explanation-5: -The vestigial tailbone in humans is homologous to the functional tail of other primates. Thus vestigial structures can be viewed as evidence for evolution: organisms having vestigial structures probably share a common ancestry with organisms in with organisms in which the homologous structure is functional.