Which events are likely to be catastrophic to an ecosystem? Select the three correct answers.
A. Introduction of a species that reproduces quickly
B. Volcanic eruption
C. Average annual snow melt
D. Tornado
E. Change in leaf color in the fall

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.