Explain the purpose of a molecular clock and the properties that a section of protein must have to be used in this way.

Humans are believed to have evolved in coastal regions in east africa. the region had an abundant supply of fish for early humanoids to eat. when scientists analyze the fads gene they see an interesting pattern. people whose families have lived in this area of east africa for generation show a high level of diversity in alleles for the fads gene. conversely, people whose families had migrated inland a moderate distance from sources of fish showed a much lower diversity for fads gene alleles. additionally, the fads alleles found in people whose family has lived inland for generation are almost all gene alleles which produce fads proteins with a high level of function and activity. how do anthropologists explain this?

Quick asap will give brainiest ! what best describes the same pattern of tides on earth throughout the day? neap tides spring tides semidiurnal tides nocturnal tides

How does the nervous system affect the excretory system?