(materials). A solvent in whose molecules there is either a permanent separation of positive and negative charges, or the centers of positive and negative charges do not coincide; these solvents have high dielectric constants, are chemically active, and form coordinate covalent bonds; examples are alcohols and ketones.1  Facebook.materials). A solvent in whose molecules there is either a permanent separation of positive and negative charges, or the centers of positive and negative charges do not coincide; these solvents have high dielectric constants, are chemically active, and form coordinate covalent bonds; examples are alcohols and ketones.
The bottleneck effect. The bottleneck effect is an extreme example of genetic drift that happens when the size of a population is severely reduced. Events like natural disasters (earthquakes, floods, fires) can decimate a population, killing most indviduals and leaving behind a small, random assortment of survivors.
A population bottleneck arises when a significant number of individuals in a population die or are otherwise prevented from breeding, resulting in a drastic decrease in the size of the population. Genetic drift can result in the loss of rare alleles, and can decrease the size of the gene pool.Genetic drift can also cause a new population to be genetically distinct from its original population, which has led to the hypothesis that genetic drift plays a role in the evolution of new species. population bottleneck arises when a significant number of individuals in a population die or are otherwise prevented from breeding, resulting in a drastic decrease in the size of the population. Genetic drift can result in the loss of rare alleles, and can decrease the size of the gene pool.