Understanding Biology - Chapter 19: Genes Within Populations

Flashcards covering important vocabulary and concepts related to genes within populations and evolutionary biology.

Evolution

The process by which an entity changes through time, resulting in variation within natural populations.

Natural Selection

The mechanism proposed by Darwin whereby individuals with favorable traits are more likely to survive and reproduce.

Genetic Variation

Differences in alleles of genes found within individuals in a population, providing the raw material for natural selection.

Hardy-Weinberg Equilibrium

A principle stating that allele and genotype frequencies in a population remain constant in the absence of evolutionary influences.

Mutation

A change in the DNA sequence of an organism, which is a source of genetic variation in populations.

Gene Flow

The movement of alleles from one population to another, which can influence genetic diversity.

Nonrandom Mating

A mating pattern in which individuals select partners based on specific traits, affecting allele frequencies in future generations.

Genetic Drift

Random changes in allele frequencies in small populations due to chance events.

Bottleneck Effect

A sharp reduction in population size, leading to a decrease in genetic diversity.

Heterozygote Advantage

A situation in which heterozygous individuals have a survival advantage over homozygous individuals.

Sexual Selection

A mode of natural selection where certain traits increase an individual's chances of attracting mates.

Directional Selection

A type of selection that favors one extreme phenotype over others, causing a shift in the population's trait distribution.

Stabilizing Selection

Selection that favors intermediate phenotypes and selects against extreme variations.

Disruptive Selection

Selection that favors extreme phenotypes at both ends of the distribution, potentially leading to speciation.

Phenotype

The observable physical or biochemical characteristics of an organism, determined by its genotype.

Allele Frequency

The relative frequency of an allele at a genetic locus in a population.

SNP (Single Nucleotide Polymorphism)

A DNA sequence variation that occurs when a single nucleotide is altered, playing a key role in genetic variation.