Natural Selection and Evolution Review

These flashcards cover key vocabulary terms and concepts related to natural selection and evolution as discussed in the lecture.

Use and Disuse

The theory that organisms lose parts because they do not use them, such as the missing eyes in tapeworms.

Perfection with Use and Need

The concept that the constant use of an organ results in its increased size, exemplified by the muscles of a blacksmith or large ears of night-flying bats.

Natural Selection

The process where individuals with traits that help them survive and reproduce in a specific environment leave more offspring than others.

Gene Pool

The total collection of alleles for all loci in a population.

Overproduction

The tendency of living things to produce more offspring than the environment can support.

Biotic Factors

Influences from living organisms in an environment.

Abiotic Factors

Influences from the physical environment, such as sunlight, pH, and temperature.

Directional Selection

Natural selection favoring individuals at one extreme of a trait, resulting in a shift towards that trait.

Disruptive Selection

Natural selection favoring individuals at both extremes of a trait, leading to increased fitness compared to intermediate traits.

Microevolution

A change in allele frequencies in a population over generations.

Artificial Selection

The process by which humans breed organisms for desired traits, leading to changes in allele frequencies.

Genetic Drift

Random changes in allele frequencies in a population due to chance events.

Bottleneck Effect

A sharp reduction in the size of a population due to environmental events, leading to a loss of genetic diversity.

Founder Effect

The reduced genetic diversity that results when a population is established by a very small number of individuals.

Hardy-Weinberg Equilibrium

A principle stating the allele frequencies in a population remain constant in the absence of evolutionary influences.

Fitness

A relative measure of reproductive success in an environment.

Coevolution

The process where two species evolve in response to each other, often due to interdependencies.

Speciation

The origin of new species, which occurs when populations become reproductively isolated.

Prezygotic Barriers

Reproductive barriers that prevent fertilization from occurring, such as habitat or temporal isolation.

Postzygotic Barriers

Reproductive barriers that occur after fertilization, such as hybrid viability or fertility issues.

Lactose Tolerance

An example of phenotypic variation resulting from a single gene variant that provides a survival advantage.

Cladistics

The classification of organisms based on common ancestry, emphasizing evolutionary relationships.

Abiogenesis

The hypothesis that life arose from nonliving matter through natural processes.