Which of the following ranching practices contributes to soil erosion?
a.
overgrazing of livestock
b.
grazing more than one type of animal on the land
c.
grazing the same type of animal on the land for many years
d.
allowing fields to remain empty and unused.

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.