7.4-7.5: Population Genetics

Population

A group of individuals of the same species living in the same area at the same time.

Population Genetics

The study of genetic variations within populations, involving the measurement of genotype, allele, and phenotype frequencies.

Gene Pool

A population's genetic makeup.

Microevolution

The gradual change in the frequency of a gene in a population over time.

Hardy-Weinberg Equilibrium

A state where allele frequencies remain constant, indicating that a population is not evolving.

Hardy-Weinberg Equilibrium Conditions

1. Large population size, 2. Random mating, 3. No gene flow, 4. No mutations, 5. No natural selection.

Natural Selection

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

Genetic Drift

Change in a population’s genetic makeup due to random events, having greater effects on smaller populations.

Founder Effect

When a few individuals emigrate and establish a new population in a new location.

Bottleneck Effect

A sudden event that causes a major reduction in population size, leading to decreased genetic diversity.

Gene Flow

The movement of alleles from one population to another.

Random Mutations

Changes in the DNA sequence that occur by chance and can introduce new alleles.

Hardy-Weinberg Equation for Allele Frequencies

p + q = 1, where p is the frequency of the dominant allele and q is the frequency of the recessive allele.

Hardy-Weinberg Equation for Genotype Frequencies

p² + 2pq + q² = 1.

Frequency of Homozygous Dominant

p², representing the proportion of individuals with two dominant alleles.

Frequency of Heterozygous

2pq, representing the proportion of individuals with one dominant and one recessive allele.

Frequency of Homozygous Recessive

q², representing the proportion of individuals with two recessive alleles.