Microevolution: Natural Selection and Genetic Drift

This set of flashcards covers key vocabulary related to microevolution, natural selection, and genetic drift as presented in the laboratory notes.

Evolution

A change in allele frequencies within a population over time.

Fitness

A measure of an individual's reproductive success, defined by the number of surviving offspring produced.

Natural Selection

A mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce.

Genetic Drift

A random change in allele frequencies in a population due to chance events.

Microevolution

Evolutionary changes that occur within a population over generations.

Macroevolution

Evolutionary change on a scale that results in the emergence of new species.

Gene Pool

The complete set of genetic information within a population, including all alleles of all genes.

Adaptation

A trait that increases an organism's fitness and becomes more common in a population over time due to natural selection.

Artificial Selection

The process where humans selectively breed individuals for desired traits.

Selective Pressure

Environmental factors that influence which traits are advantageous for survival and reproduction.

Population

A group of individuals of the same species living in the same geographical area that can interbreed.

Mutation

A permanent alteration in the DNA sequence of an organism's genome.

Independent Assortment

The process where different genes independently separate from one another when reproductive cells develop.

Crossing Over

The exchange of genetic material between homologous chromosomes during meiosis.

Random Fertilization

The unpredictable combination of egg and sperm, each with unique genetic material, at conception.

Selection Process

The overall mechanism by which certain individuals or traits are favored in a population, leading to differential survival and reproduction.

Survival of the Fittest

A phrase that describes the mechanism of natural selection, where organisms best adapted to their environment are more likely to survive and pass on their genes.

Impact of Population Size

Smaller populations are more susceptible to genetic drift, which can lead to rapid and unpredictable changes in allele frequencies, reducing genetic variation.

Example of Natural Selection

The peppered moth in industrial England, where darker moths became more common due to their camouflage on soot-covered trees, increasing their survival against predators.

Example of Genetic Drift

The bottleneck effect, such as when a natural disaster drastically reduces a population's size, leading to a random shift in the remaining allele frequencies of the survivors.