Introduction to Evolution

These flashcards cover key vocabulary and concepts related to the topic of evolution as discussed in the lecture.

Evolution

A change in a species over time involving the entire population rather than individuals.

Mutation

A change in DNA which leads to changes in nucleotide sequences and ultimately proteins.

Helpful Mutation (Adaptation)

A beneficial change that enhances an organism's ability to survive, reproduce, and thrive in its environment.

Fitness

An organism's ability to survive and reproduce in a particular environment.

Selective Pressure

Factors that cause the less fit organisms to die out, driving natural selection.

Sex Selection

A form of natural selection driven by changes in mating behavior.

Speciation

The emergence of new species as a result of evolutionary processes.

Reproductive Isolation

Condition necessary for speciation, where a changing population no longer reproduces with an unchanging population.

Genetic Drift

Changes in allele frequencies in a population due to chance events, not natural selection.

Bottleneck Effect

A significant reduction in population size due to a disaster, leading to reduced genetic diversity.

Founder Effect

When a small group of individuals moves to a new area, establishing a new population with limited genetic variation.

Stabilizing selection

• Favors average (peak in middle)

• Fitness is highest with moderate trait expression

Directional selection

• One of the extremes is the most fit

• As a trait increases, fitness increases

Disruptive selection

• Selection favors both extremes

• A yellow animal blend with flowers and green blends with leaves, a medium one is cooked

Geographical isolation

change in location which seperates populations

Habitat isolation

same area diff habitats, ground vs. trees

Temporal isolation

mate at diff times

behavioral isolation

diff mating rituals or chemical signals

mechanical isolation

parts dont fit

Gamete isolation

genes are incompatible