Exam 3 Study Guide - Fall 2024

A compilation of key vocabulary terms and definitions to review for the exam.

Molecular Clock

A method used to estimate evolutionary time by measuring random neutral mutations in DNA that occur at a constant rate.

Natural Selection

The process by which organisms better adapted to their environment are more likely to survive and reproduce.

Stabilizing Selection

A natural selection process where average or moderate traits in a population are favored, leading to higher survival rates.

Diversifying Selection

A type of selection that favors multiple extreme phenotypes within a population, increasing genetic diversity.

Directional Selection

Natural selection that favors one extreme phenotype, causing a shift in the population in that direction.

Kin Selection

A natural selection process that favors traits aiding an organism's relatives to reproduce, potentially at the cost of the individual.

Altruism

Behaviors that benefit another individual at a cost to oneself; it can enhance the survival of a species.

Batesian Mimicry

A harmless species evolving to imitate the appearance of a harmful species.

Müllerian Mimicry

Two or more harmful species evolving to resemble each other, reinforcing predator avoidance.

Founder Effect

Genetic variation reduction in a population that occurs when a small group starts a new population.

Inbreeding Depression

Reduced biological fitness in a population due to inbreeding that increases harmful recessive traits.

Red Queen Hypothesis

A hypothesis stating that species must constantly evolve to maintain fitness against others that are also evolving.

Ecdysozoa

A major animal group that includes species defined by their ability to shed an exoskeleton (molting).

Ecosystem Services

Benefits that ecosystems provide to humans, including regulation of air quality, nutrient cycling, and recreation.