LIFE SCIENCE

Detailed explanation-1: -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-2: -Embryology is important to understanding a species’ evolution, since some homologous structures can be seen only in embryo development. For example, all vertebrate embryos, from humans to chickens to fish, have a tail during early development, even if that tail does not appear in the fully developed organism.

Detailed explanation-3: -Many traits of one type of animal appear in the embryo of another type of animal. For example, fish embryos and human embryos both have gill slits. In fish they develop into gills, but in humans they disappear before birth.

Detailed explanation-4: -Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants. Figure below shows the hands of several different mammals. They all have the same basic pattern of bones.

Detailed explanation-5: -Comparative embryology is the study of the similarities and differences in the embryos of different species. Similarities in embryos are evidence of common ancestry. All vertebrate embryos, for example, have gill slits and tails (see the Figure below).