Which of the following causes the jet stream?

high altitude clouds
low altitude clouds
differences in size between two air masses
differences in temperature between two air masses

Gene flow and genetic drift both affect allele frequencies in a population. a high level of gene flow into a population genetic diversity in a population. a high level of gene flow out of a population genetic diversity in a population. genetic drift is the change in allele frequencies due to factors. typically, genetic drift has the biggest impact on populations.