The random changes in a population's allele frequencies are referred to as
A. genetic flow
B. genetic drift
C. selective pressure D. artificial selection

The gene that causes sickle-cell disease is present in a higher percentage of residents of sub-saharan africa than among those of african descent living in the united states. even though this gene causes sickle-cell disease, it also provides some protection from malaria, a serious disease that is widespread in sub-saharan africa but absent in the united states. discuss an evolutionary process that could account for the different percentages of the sickle-cell gene among residents of the two regions.

Which geologic feature would most likely be represented by contour lines john far apart from one another? a cliff a hill a plain a valley

Pl as time goes by and water goes through the water cycle again and again, the amount of water on earth: increases decreases ostays the same goes up and down