LIFE SCIENCE

Detailed explanation-1: -This shows that the animals are similar in origin and that they develop similarly, implying that they are related, have common ancestors.

Detailed explanation-2: -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-3: -Vertebrate Embryonic Development Vertebrates during the early stages of embryonic development are all quite similar due to common ancestry. The genes that direct embryonic development are the same among vertebrates.

Detailed explanation-4: -While these animals all look very different from each other, they have strong similarities in their embryonic development, which suggests an evolutionary link. Most of these similarities occur in the earliest stages of embryonic development.

Detailed explanation-5: -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.