Explain Adaptation Through Selection - Biology

Beneficial alleles increase in frequency across generations. Requires multiple generations for allele frequency changes.

The proportion of a specific allele among all alleles in a population. Measures relative abundance of genetic variants.

Selection favors one extreme phenotype, shifting the population mean. Moves population toward one extreme of trait distribution.

Selection favors intermediate phenotypes, reducing variation. Maintains population average by eliminating extremes.

Selection favors both extremes over intermediates. Splits population into two distinct forms.

Selection for traits that increase mating success. Enhances reproduction through mate choice or competition.

Human-directed breeding that changes trait frequencies. Similar to natural selection but human-controlled.

Predator. Environmental factors that cause differential survival.

A trait can be beneficial in one environment and harmful in another. Selection's effectiveness depends on environmental context.

An environmental factor that influences survival or reproduction. Determines which traits provide survival advantage.

Recombination (crossing over and independent assortment). Shuffles existing alleles into new combinations.

Mutation. Creates new variants for selection to act upon.

Individuals with certain traits leave more offspring than others. Key mechanism driving evolutionary change over time.

The ability of a trait to be passed genetically to offspring. Determines if traits can respond to selection pressure.

Differences in alleles among individuals in a population. Provides raw material for natural selection to act upon.

Heritable variation. Traits must be genetically passed to offspring for selection.

A benefit in one function comes with a cost in another. Optimization in one trait may reduce another trait.

A limit on evolution due to genetics, development, or history. Physical or historical limits on evolutionary change.

Random changes in allele frequencies, strongest in small populations. Non-selective evolutionary force affecting all populations.

Genetic drift when a new population is started by few individuals. Reduces genetic diversity in new populations.

Genetic drift after a population size is drastically reduced. Severe population reduction causes random allele loss.

Movement of alleles between populations via migration and mating. Homogenizes allele frequencies between populations.

Allele frequencies in a population change across generations. Evolution changes genetic composition over time.

Selection favors observable traits that affect survival or reproduction. Selection acts on visible traits, not directly on genes.

Population. Evolution occurs at the population level, not individual.

Relative reproductive success in a given environment. Measures how many offspring an individual produces.

Unequal reproductive success (differential reproduction). Differential reproduction is essential for selection.

Differential survival and reproduction due to heritable variation. Individuals with better traits survive and reproduce more.

A heritable trait that increases fitness in a specific environment. Must enhance survival/reproduction and be passed to offspring.