Genetic drift, the founder principle, and the bottleneck effect all occur under what conditions?
a. in small populations when one genetic trait becomes more common in a population purely by chance
b. in small populations and result in a decrease in genetic diversity and/or an increase in the occurrence of specific genetic traits
c. when a small group of organisms only reproduce with each other to create a larger population of organisms
d. when the majority of a population is decimated and there are only a few remaining organisms left to rebuild the population
if answered

Answer;

d. when the majority of a population is decimated and there are only a few remaining organisms left to rebuild the population

Explanation;

-Genetic drift can have major effects when a population is sharply reduced in size by a natural disaster (bottleneck effect) or when a small group splits off from the main population to found a colony (founder effect).

-Population bottlenecks occur when a population's size is reduced for at least one generation. Because genetic drift acts more quickly to reduce genetic variation in small populations, undergoing a bottleneck can reduce a population's genetic variation by a lot, even if the bottleneck doesn't last for very many generations.

Genetic drift, the founder principle, and the bottleneck effect all occur under the conditions when the majority of a population is decimated and there are only a few remaining organisms left to rebuild the population. The answer is letter D. 

its a  

explanation:

answer: land bridge theory. land bridge theory held that shifting portions of dry land explained the finding of identical species on different continents. plate tectonic theory eventually eliminated the land bridge theory.