AP BIOLOGY

Detailed explanation-1: -Embryos of different species have differences and similarities in structures up to a certain period during gestation. Human, pig, reptile, and bird embryos have similar embryonic development but as they grow, they transform into their respective species. This demonstrates common ancestry.

Detailed explanation-2: -Embryology is a branch of comparative anatomy which studies the development of vertebrate animals before birth or hatching. Like adults, embryos show similarities which can support common ancestry.

Detailed explanation-3: -Homologous structures provide evidence for common ancestry, while analogous structures show that similar selective pressures can produce similar adaptations (beneficial features). Similarities and differences among biological molecules (e.g., in the DNA sequence of genes) can be used to determine species’ relatedness.