What is desertification? method of using desert land for agriculture
b. the process of turning arable land into deserts
drying up of stream beds and lakes
d. the expansion of current deserts land areas

Which of the following factors would not contribute to allopatric speciation? a) a population becomes geographically isolated from the parent population.b) the separated population is small, and genetic drift occurs.c) the isolated population is exposed to different selection pressures than the ancestral population.d) different mutations begin to distinguish the gene pools of the separated populations.e) gene flow between the two populations is extensive.