Human appendix and Gene's Rate Evolution

The human appendix, a vestigal extension off the large intestine, is homologous to a structure called a caecum, generally larger than our appendix, and houses bacteria that aid in digesting cellulose, the main component of plants.

Explain how the presence of the appendix might be used to show our common ancestry with other mammals, and determine what it might tell us about the dietary history of humans. Provide an example with your response.

Geneticists compare DNA base sequences among organisms and from this data determine a gene’s rate of evolution. Different genes have been found to evolve at different rates.

Explain why some genes might have faster rates of evolution than other genes as populations adapt to their environments, and give an example with your explanation.