Ch.16 Population_Genetics

These are flashcards made based off of Ch.16 study guide and ppt.

What are the five conditions necessary to maintain Hardy-Weinberg equilibrium?

No mutation, No migration (gene flow), Large population size, Random mating, No natural selection.

What role does mutation play in microevolution?

Introduces new alleles into a population, affecting gene frequencies.

How does gene flow contribute to microevolution?

Involves the migration of individuals, which introduces new alleles and alters allele frequencies in a population.

What is genetic drift, and how does it affect populations?

Refers to random fluctuations in allele frequencies that can significantly impact small populations.

Bottleneck effect

A dramatic reduction in population size reduces genetic diversity.

Founder effect

A small group establishes a new population, leading to reduced genetic variation.

Assortative mating

Individuals choose mates based on particular traits, impacting allele frequencies.

Natural Selection

Different survival and reproduction rates of individuals with varying phenotypes lead to changes in allele frequencies.

Types of natural selection

Stabilizing, directional, disruptive, and balancing (heterozygote advantage).

Stabilizing selection

Favors average phenotypes, reducing variation within a population.

Directional selection

Favors one extreme phenotype, resulting in a shift in the population's trait distribution toward that extreme.

Disruptive selection

Favors extreme phenotypes at both ends of the trait spectrum, which can lead to speciation.

Balancing selection (heterozygote advantage)

Maintains multiple phenotypes in a population, often through the advantages conferred to heterozygous individuals.

Types of Sexual Selection

Includes various mechanisms by which certain traits increase an individual's chances of mating.

Female Choice

Females select mates based on specific traits.

Good Genes Hypothesis

Females prefer males with indicators of genetic fitness.

Runaway Hypothesis

Preference for certain male traits can become a feedback loop, enhancing those traits.

Male Competition

Males compete for access to females.

Dominance Hierarchies

Social ranking that can influence mating success.

Sexual Dimorphism

Differences in traits between sexes that arise due to sexual selection.

Evolution

Change in allele frequencies in a population over time.

Microevolution

Small-scale changes in allele frequencies within a population.

Population

A group of individuals of the same species that can interbreed.

Population Genetics

The study of genetic variation within populations and how it changes over time.

Gene Pool

The total collection of alleles in a population.

Allele

Different forms of the same gene.

Allele Frequency

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

Reproductive Isolation

Mechanisms that prevent different species from mating.

Fitness

The ability of an individual to survive and reproduce in its environment, contributing to the gene pool of subsequent generations.