Macroevolution

Microevolution

Small genetic changes within a species that lead to variation or subspecies, not major group changes.

Macroevolution

Evolutionary change at or above the species level, involving speciation, extinction, and major structural changes over millions of years.

Archaeopteryx

A transitional fossil that shows both reptilian and avian traits, serving as evidence for macroevolution and common ancestry.

Adaptive Radiation

Rapid diversification from one common ancestor, often occurring when organisms enter a new environment.

Coevolution

The process by which two or more species evolve in response to each other, such as predator-prey or flower-pollinator relationships.

Convergent Evolution

The evolution of similar traits in unrelated species, driven by similar environmental pressures, resulting in analogous structures.

Extinction

The complete disappearance of a species, which alters the evolutionary pathways of remaining organisms.

Punctuated Equilibrium

The theory that evolution occurs in short bursts separated by long periods of stasis, often triggered by geographic isolation or other factors.

Phyletic Gradualism

The concept that evolution occurs slowly and continuously, with small changes accumulating over long periods.

Trilobites

Marine arthropods with a good fossil record, serving as key evidence for punctuated equilibrium, particularly in relation to their eye loss in deep-water habitats.