In determining species, it is best to differentiate in terms of the population that is being adapted in which, a certain niche. So, if it has a small gene pool, and the different species will be interbreeding each other with a much genetic variability in gene pool, it would most likely cause a less adaptation. The niche will be having a less adaptation if too much genetic variability will occur.
Answer:
(A) The variation resulting from meiosis and the union of gametes means some individuals will have a chance of colonizing diverse distant environments successfully.
(D) Vegetative propagation is more efficient than sexual reproduction when the current generation is well adapted to the local environment.
Explanation:
Sexual or asexual (options B and C) are not a "last ditch", it pretty much depends on the type of organism and its strategy for survival. There are thousands of organisms that can reproduce either sexually or asexually depending on the environmental conditions.
Option A. Genetic variability is important because sometimes the genetic variability produce during the sexual reproduction processes (crossing over, chromosomes assortment and DNA from 2 parents) can confer an organism the adaptability mechanism to thrive in different environments.
Option D. Since asexual reproduction delivers genetical equal organisms, the offspring is already adapted to local conditions and can colonize at a faster rate.
