Evolution & Population Genetics

This set of flashcards covers key concepts and vocabulary related to evolution, population genetics, and plant biology as discussed in the lecture notes.

Directional Selection

Favors one extreme phenotype over others, shifting the population's trait distribution in one direction.

Stabilizing Selection

Favors the average phenotype and reduces variation, maintaining the status quo.

Disruptive Selection

Favors both extreme phenotypes over the intermediate, potentially leading to speciation.

Natural Selection

The process where individuals with favorable traits survive and reproduce more successfully.

Adaptation

A heritable trait that increases an organism’s fitness in its environment.

Fitness

An organism’s ability to survive and reproduce in its environment.

Genetic Drift

Random changes in allele frequencies, especially in small populations.

Gene Flow

Movement of alleles between populations, often through migration.

Mutation

Random change in DNA sequence, the source of new genetic variation.

Hardy-Weinberg Equilibrium

A condition where allele and genotype frequencies remain constant in a population.

Prezygotic Barriers

Factors that prevent fertilization from occurring before zygote forms.

Postzygotic Barriers

Factors that reduce the viability or reproductive capacity of hybrid offspring.

Homology

Similar structures due to shared ancestry.

Analogy

Similar function due to convergent evolution, not due to shared ancestry.

Monophyletic Group

Includes a common ancestor and all its descendants.

Paraphyletic Group

Includes a common ancestor but not all descendants.

Polyphyletic Group

Does not include the most recent common ancestor.

Endosymbiotic Theory

The theory that eukaryotic cells arose from larger prokaryotes engulfing smaller ones.

Mycorrhizae

Symbiotic relationship between fungi and plant roots that helps absorb nutrients.

R-strategy

Reproductive strategy characterized by many offspring with low survival.

K-strategy

Reproductive strategy characterized by fewer offspring with high investment in survival.