Exam 21: Microevolution: Genetic Changes Within Populations

The phenomenon of chance events causing the allele frequencies in a population to change unpredictably is known as ____.

Genetic drift can eliminate alleles from a population more quickly than natural selection.

The fossil record reveals that the structure of shoulder joints in birds, which is essential for flight, is an adaptation that originated in ____.

Inbreeding is primarily due to ____.

Snow geese usually select mates of their own color, an example of ____.

For an autosomal gene locus, there are ____ possible genotypes and ____ possible alleles.

Most new alleles probably arise from ____.

Genetic drift will have a progressively larger impact on allele frequencies in a population as ____.

Natural selection that shifts the adaptation of an entire population toward one extreme is known as ____.

Genetic variation can originate both from the production of new alleles and from the arrangement of existing alleles.

What is the most accurate definition of microevolution?

Research by Malte Andersson suggests the long tail feathers of male African widowbirds are a product of ____ selection because females are more strongly attracted to males with long tails than to males with short tails.

Dispersal agents, such as pollen-carrying wind or seed-carrying animals, are responsible for ____ in most plant populations because they often introduce novel alleles into a population.

The existence of discrete variants of a particular character is known as ____.

The sum of all gene copies at all gene loci in all individuals in a population defines a ____.

In some studies that use observational rather than experimental data, investigators develop ____, which conceptually predict what they would see if a particular factor had no effect.

The stable presence of two or more phenotypes in a population is called a ____.

The gene locus governing flower color in snapdragons exhibits ____ because heterozygous individuals appear pink while homozygous individuals are either white or red.

The process by which successful traits become more common in subsequent generations is called ____.

The agent of microevolutionary change that is most likely to introduce genetic variation from another population is referred to as ____.