Evolution and Population Genetics

This set covers the fundamental concepts of evolutionary biology, including historical figures, population genetics, Hardy-Weinberg principles, and agents of evolution as outlined in the Chapter 12 guide.

Evolution

A process that acts on populations over time, involving changes in allele frequencies and traits across generations.

Common descent with modification

Darwin's description of evolution suggesting that species change over time, give rise to new species, and share a common ancestor.

Malthus

An economist whose work on population growth and limited resources contributed to Darwin’s views on the struggle for existence and natural selection.

Cuvier

A scientist whose paleontological work provided historical data and information on extinction that helped shape the theory of evolution.

Von Baer

A scientist who argued that life is not a series, noting that embryos of different species do not pass through the adult stages of 'lower' organisms.

Lyell

A geologist whose studies of slow, continuous geologic processes supported the idea that the Earth is very old, providing the time scale necessary for natural selection to occur.

Natural selection

The process by which individuals with certain heritable traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Polyallelic

A term describing a gene that has multiple alleles existing within a population.

Gene pool

The total collection of all genes and their various alleles found within a specific population at a given time.

Allele frequency

A measure of how common a specific allele is in a population, calculated by dividing the number of copies of that allele by the total number of alleles for that gene in the population.

Species

A group of organisms that are able to interbreed with one another and produce viable offspring.

Viable

A requirement for offspring to be considered successful members of a species, meaning they are capable of surviving and reproducing.

Population

A group of individuals of the same species that live in the same geographic area and interbreed.

Hardy-Weinberg Equilibrium

A theoretical state where allele frequencies in a population stay constant over generations; it involves the formulas $p + q = 1$ and $p^2 + 2pq + q^2 = 1$.

Agents of evolution

The five mechanisms that can change allele frequencies in a population: mutation, gene flow, non-random mating, genetic drift, and natural selection.

Heritable

Refers to traits or characteristics that can be passed from parents to their offspring through genetic information.

Fitness

The relative reproductive success of an individual; the principle that in nature there is no absolute 'fit,' only individuals that are 'fitter' than others in a specific environment.

Modes of natural selection

The three primary ways natural selection affects a population: directional selection, stabilizing selection, and disruptive selection.

Selective pressure

Any external factor (such as predators, climate, or food availability) that alters the behavior and fitness of living organisms within a given environment.

Artificial selection

The process by which humans consciously select for or against particular features in organisms, such as breeding specific plants or animals.

Sexual dimorphism

The condition where the two sexes of the same species exhibit different characteristics beyond the differences in their sexual organs, maintained by natural selection.

Embryo Selective Pressures

The concept that natural selection primarily drives changes in adults rather than embryos, as selective pressures generally do not affect the earliest stages of development in the same way they affect independent organisms.