Evolution and Biodiversity

Genetics

The study of heredity.

Genes

Chunks of DNA that carry genetic information.

Alleles

Different forms of the same gene.

Chromosomes

Structures that contain two copies of each gene, organized in pairs (23 pairs total).

Evolution

Change in allele frequency in a population over time.

Mutation

A change in the DNA sequence.

Advantageous Mutation

Mutations that code for new traits that increase fitness.

Deleterious Mutation

Mutations that code for new traits that reduce fitness.

Neutral Mutation

Mutations that neither change nor affect fitness.

Gene Flow

The introduction of new individuals with different allele frequencies to a population.

Genetic Drift

Random changes in allele frequencies due to chance events.

Bottleneck Effect

An event that results in a drastic reduction of a population size.

Natural Selection

The process by which some traits help survival and increase in frequency.

Evolutionary Adaptation

Increase in frequency of traits within a population that suit it to its environment.

Species

A group of individuals that can interbreed and produce fertile offspring.

Speciation

The process by which one species splits into two species.

Allopatric Speciation

Speciation that occurs due to physical barriers separating populations.

Sympatric Speciation

Speciation that occurs in the same area but different habitats.

Gametic Isolation

A reproductive barrier where species' gametes cannot fuse.

Mechanical Isolation

A reproductive barrier where species' genital openings cannot align.

Transitional Forms

Fossils that link the past and present species.

Biogeography

The study of the geographic distribution of species.

Comparative Anatomy

The comparison of body structures between different species.

Vestigial Structures

Leftover structures from ancestors that are no longer functional.

Comparative Embryology

The study of similarities in early developmental stages among different species.