Lecture 15: Natural Selection and Population Genetics

These flashcards cover key vocabulary terms and definitions related to natural selection and population genetics as discussed in the lecture.

Natural Selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Direction Selection

Favors one extreme phenotype, causing the average phenotype in the population to change in one direction.

Stabilizing Selection

Favors phenotypes near the middle of the range of phenotypic variation, maintaining average phenotype.

Disruptive Selection

Intermediate phenotypes are selected against and extreme phenotypes are favored, increasing variation.

Balancing Selection

Occurs when no single allele has a distinct advantage, maintaining genetic variation within a population.

Heterozygote Advantage

When heterozygous individuals have higher fitness than homozygous individuals.

Fitness

A quantitative representation of reproductive success.

Speciation

The formation of new and distinct species in the course of evolution.

Phenotype

The set of observable characteristics of an individual resulting from the interaction of its genotype with the environment.

Alleles

Different versions of a gene that determine distinct traits inherited from parents.