Macroevolution

Macroevolution

Large-scale evolutionary changes that occur over long periods of time, resulting in the emergence of new species, genera, families, and other higher taxa.

Microevolution

Small genetic changes within a species, such as allele frequency shifts.

Linnaean Classification System

A hierarchical system established in 1758 for organizing species, which is still used today.

Morphological Species Concept (MSC)

A species definition based on the distinct morphological traits of individuals.

Biological Species Concept (BSC)

A species consists of interbreeding populations that produce fertile offspring and are reproductively isolated from others.

Recognition Species Concept (RSC)

A species is a group of organisms that recognize each other as mates.

Ecological Species Concept (ESC)

A species is a group of organisms that exploit a single ecological niche.

Evolutionary Systematics

A classification approach based on presumed ancestors and evolutionary history.

Cladistics

A classification system based only on shared derived traits without assumptions about ancestry.

Homologies

Traits inherited from a common ancestor.

Analogies

Similar traits that arise from convergent evolution rather than common ancestry.

Phylogenetic Tree

Diagrams that show evolutionary relationships based on ancestor-descendant lineage.

Cladogram

Branching diagrams showing relationships based only on shared derived traits.

Allopatric Speciation

Speciation that occurs when populations are geographically separated.

Parapatric Speciation

Speciation that occurs in adjacent habitats with limited overlap.

Sympatric Speciation

Speciation that occurs within the same geographic area.

Adaptive Radiation

Rapid diversification of species to fill new ecological niches.

Gradualism

An evolutionary model that suggests slow, continuous evolution over time.

Punctuated Equilibrium

An evolutionary model where evolution occurs in rapid bursts followed by long periods of stability.