Sexual Selection, Mating Systems, and Population Genetics

A comprehensive collection of vocabulary flashcards covering concepts of sexual selection, male and female mating strategies, mating systems, and population genetics based on the lecture notes.

Sexual selection

A mechanism of evolution where individuals with certain traits are more likely to obtain mates than individuals without those traits.

Intrasexual selection

A form of sexual selection (same-sex competition) where members of the same sex compete directly with each other for access to mates, often resulting in weaponry, size dimorphism, or sperm competition.

Intersexual selection

A form of sexual selection (mate choice) where individuals of one sex choose mates based on specific traits, often leading to showy ornamentation or complex courtship displays.

Sexual dimorphism

A phenotypic difference in appearance and/or behavior between the males and females of the same species.

Polygynous mating system

A mating system where one male mates with multiple females, typically favored when males can control valuable resources or access multiple females.

Polyandrous mating system

A mating system where one female mates with multiple males, expected when males provide substantial parental care allowing females to mate again.

Monogamous mating system

A mating system where one male mates with one female, favored when offspring require significant parental care from both parents or when mates are widely scattered.

Promiscuous mating system

A mating system where both males and females mate with multiple partners with no long-term pair bonds or mate preference.

Female defense polygyny

A male mating strategy where males directly guard or defend a clumped group of females from rival males.

Resource defense polygyny

A male mating strategy where males defend a territory containing essential resources (such as food or nesting sites) required by females.

Lekking

A male mating strategy where males set up and perform courtship displays in localized areas of high female traffic (leks) to attract choosy females.

Sneaking strategy

A male mating strategy where younger or smaller males bypass territory defense and sneak in to court females or fertilize eggs while dominant males are occupied.

Scramble competition strategy

A male mating strategy used when females are scattered unpredictably across a landscape, requiring males to search to find and guard females.

Direct benefits

Resources provided directly to a female or her offspring by a male, such as food, territory, protection, or parental care.

Indirect benefits

Genetic advantages passed to offspring when a female selects a mate with superior genetic quality.

Good genes hypothesis

The hypothesis that females choose mates based on traits that serve as honest indicators of high genetic quality, such as disease resistance or overall vigor.

Mate choice copying

A social mating behavior in which an individual's mate preference is influenced by observing the mating choices of other females.

Evolution

A change in allele frequencies within a population over generations.

Hardy-Weinberg equilibrium

A null model describing a population that is not evolving at a given locus, maintained under five assumptions: no mutation, no gene flow/migration, no natural selection, very large population size, and random mating.

Hardy-Weinberg allele frequency equation

The mathematical equation $p + q = 1$, where $p$ is the frequency of the dominant allele $A$ and $q$ is the frequency of the recessive allele $a$.

Hardy-Weinberg genotype frequency equation

The mathematical equation $p^2 + 2pq + q^2 = 1$, where $p^2$ represents the frequency of $AA$, $2pq$ represents the frequency of $Aa$, and $q^2$ represents the frequency of $aa$.

Genotype

The specific genetic composition of an organism at a given locus (e.g., $AA$, $Aa$, or $aa$).

Phenotype

The observable physical or behavioral characteristics of an organism, determined by the interaction of its genotype and environment ($\text{Genotype} + \text{Environment} \rightarrow \text{Phenotype}$).

K-selected species

Species characterized by long lifespans, low reproductive rates, and high investment in offspring survival (e.g., bears).