AP BIOLOGY

Detailed explanation-1: -Molecular clocks are used to determine how closely two species are related by calculating the number of differences between the species’ DNA sequences or amino acid sequences. Molecular evidence for evolution includes that all living things share the same biochemical building blocks.

Detailed explanation-2: -Comparing how many of the amino acids are in the same positions on the protein chain can provide some idea of how closely related two species are. For example, humans and chimpanzees only have one position where they are different on the amino chain, while humans and moths have 31 different positions.

Detailed explanation-3: -Biologists often compare the sequences of related genes found in different species (often called homologous or orthologous genes) to figure out how those species are evolutionarily related to one another.

Detailed explanation-4: -However, now scientists can also analyze DNA to discover how closely organisms are related. Every living creature has DNA, which has a lot of inherited information about how the body builds itself. Scientists can compare the DNA of two organisms; the more similar the DNA, the more closely related the organisms.