AP BIOLOGY

Detailed explanation-1: -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.

Detailed explanation-2: -Features of animals that have similar structure are classified as homologous if they have a common evolutionary origin, even if they have different functions in different animals.

Detailed explanation-3: -Genetics. One of the strongest evidences for common descent comes from gene sequences. Comparative sequence analysis examines the relationship between the DNA sequences of different species, producing several lines of evidence that confirm Darwin’s original hypothesis of common descent.

Detailed explanation-4: -Fossils, anatomy, embryos, and DNA sequences provide corroborative lines of evidence about common ancestry, with more closely related organisms having more characteristics in common. DNA underlies the similarities and differences in fossils, anatomy, and embryos.

Detailed explanation-5: -Homologous structures are similar physical features in organisms that share a common ancestor, but the features serve completely different functions. An example of homologous structures are the limbs of humans, cats, whales, and bats.