Genes & Evolution

These flashcards cover essential terms and concepts related to genes and evolution from the lecture notes.

Evolution

A change in a species over time, specifically a change in the allele frequency of a population.

Gene Pool

The complete set of genetic information within a population, consisting of all alleles for all loci.

Allele Frequency

The proportion of a specific allele among all alleles for a given gene in a population.

Mutation

Any change in the nucleotide sequences of DNA, which can introduce new genetic variation.

Natural Selection

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

Founder Effect

A phenomenon that occurs when a new population is established by a small number of individuals from a larger population, potentially leading to reduced genetic variation.

Hardy-Weinberg Principle

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

Stabilizing Selection

A type of natural selection that favors average individuals and reduces variation in a population.

Directional Selection

A type of natural selection that favors individuals at one extreme of a phenotypic range.

Disruptive Selection

A type of natural selection that favors individuals at both extremes of the phenotypic range.

Sexual Selection

A mode of natural selection where individuals with certain inherited traits are more likely than other individuals to obtain mates.

Heterozygote Advantage

A situation in which heterozygous individuals have a greater fitness than homozygous individuals, often seen in areas prone to specific diseases.

Frequency-Dependent Selection

Natural selection in which the fitness of a phenotype depends on its frequency relative to other phenotypes in a given population.

Polymorphism

The occurrence of two or more clearly different phenotypes within the same population.

Sickle Cell Anemia

A genetic disorder that causes abnormal hemoglobin, leading to distorted (sickle-shaped) red blood cells, which can block blood flow.

Antimicrobial Resistance

The ability of microbes to resist the effects of medications that once used to treat them.