Studied by 4 peopleNatural selection
________ often favors certain alleles and leads to a decrease in overall genetic variation in a population.
Genetic drift
________ is defined as a change in allele frequencies in a population that is due to chance.
Gene flow
________ occurs when individuals leave one population, join another, and breed.
Heterozygote advantage
________ occurs when heterozygous individuals have higher fitness than homozygous individuals do.
Lateral gene
________ transfer: The transfer of genetic information from one species to another, rather than from parent to offspring.
deleterious alleles
When ________ decline in frequency, purifying selection is said to occur.
error
Sampling ________ occurs when the allele frequencies of a chosen subset of a population (the sample) are different from those in the total population, by chance.
depression
Inbreeding ________ is the decline in average fitness that may take place when homozygosity increases and heterozygosity decreases in a population.
Niαtural selection
________ increases the frequency of certain alleles, the ones that contribute to reproductive success in a particular environment.
Mutαtion modifies
________ allele frequencies by continually introducing new alleles.
Genetic variation
________ is the number and relative frequency of alleles that are present in a particular population.
distinct advantage
Balancing selection occurs when no phenotype has a(n) ________.
Mutation
________ alone is usually inconsequential in changing allele frequencies at a particular gene.
Individuals
________ of the same sex sometimes compete with one another to obtain mates is referred to as intrasexual selection.
genetic bottleneck
A(n) ________ is a sudden reduction in the diversity of alleles in a population.
Hardy Weinberg
________ principle which serves as a mathematical null hypothesis for the study of evolutionary processes.
territory
A(n) ________ is an actively defended area where the owner has exclusive or semi "exclusive use.
intrasexual selection
Both intersexual and ________ help to explain why some aits differ between the sexes of the same species, a difference called sexual dimorphism.
Frequency dependent selection
________ occurs when certain alleles are favored when they are rare, but not when they are common.
Disruptive selection
________ eliminates phenotypes near the average value and favors extreme phenotypes.
Directionαl selection
________ changes the average value of a trait.
Gene flow
________ increases genetic diversity in a recipient population if new alleles arrive with immigrating individuals.
Genetic drift
________ is random with respect to fitness.
Mutations
________ are random with respect to fitness.
Natural selection
________ is the only evolutionary process that results in adaptation, but it is not the only evolutionary process that violates the Hardy- Weinberg assumptions.
Hardy Weinberg
The mathematical model underlying the ________ principle is based on five important assumptions about how populations and alleles behave:
Deleterious alleles
________ are alleles that lower fitness.
Gene flow
________ is the movement of alleles between populations.
Mutation
________ is the ultimate source of genetic variation.
Genetic drift
________ causes allele frequencies to change randomly.
Natural selection
________ occurs in four main patterns, or modes, each affecting genetic variation in different ways:
Genetic drift
________ is most pronounced in small populations.
genetic drift
Over time, ________ can lead to the random loss or fixation of alleles.
Point mutation
A change in a single base pair in DNA
Chromosome-level mutation
A change in the number or composition of chromosomes
Lateral gene transfer
The transfer of genetic information from one species to another, rather than from parent to offspring
Note 
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