With enough time and in the absence of other evolutionary mechanisms, genetic drift will a. reduce the genetic variation in a population b. increase the genetic variation in a population c. have no effect on the genetic variation of a population

When it is summer at the south pole, a. the northern hemisphere is tilted toward the sun. b. the southern hemisphere is tilted away from the sun. c. the northern hemisphere is tilted away from the sun. d. both the southern and northern hemispheres are tilted toward the sun.