What are the adaptations of bottle-nosed dolphins that allows them to thrive in the marine biome? Select all that apply.

A. narrow body to cut through waves

B. they can attach themselves to the sea floor during storms

C. they secrete gases to float in the water

D. paddle-like flippers for swimming

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?

Could anybody give me the answer to this question.

Why are recessive alleles not removed from populations over time? a.individuals can pass recessive alleles on to offspring b.recessive alleles are removed with enough time c.recessive alleles will always reappear after being removed