Lecture on Macroevolution and Extinction Events

These flashcards cover key concepts related to macroevolution, adaptive radiation, convergent evolution, extinction events, and significant examples and patterns in evolutionary history.

Macroevolution

The evolutionary processes and patterns that occur over long periods of time, resulting in large-scale changes such as the origin of major groups, adaptive radiations, and mass extinctions.

Adaptive Radiation

A process in which a single ancestral lineage rapidly diversifies into many descendant species that occupy different ecological niches.

Common Ancestry

All species in an adaptive radiation derive from the same ancestral lineage.

Trait Divergence

The evolution of different morphological or physiological traits in species that enhance performance in different environments.

Rapid Speciation

The quick emergence of numerous new species in a relatively short evolutionary time frame.

Convergent Evolution

The independent evolution of similar traits in unrelated lineages due to occupying similar ecological niches.

Ecological Opportunity

The availability of new habitats or resources that allows species to diversify rapidly due to limited competition.

Key Innovations

Novel traits that enable organisms to exploit previously inaccessible resources or environments, facilitating adaptive radiation.

Punctuated Equilibrium

A model describing the pattern in the fossil record where species appear suddenly followed by long periods of stasis.

Stasis

Long periods during which species show little or no morphological change.

Background Extinction

The ongoing, normal extinction rate caused by ecological and evolutionary processes.

Mass Extinction

A catastrophic event in which a significant percentage of species (more than 60%) disappear in a relatively short geological time.

K–Pg Mass Extinction

A major extinction event that occurred about 66 million years ago, resulting in the extinction of 60-80% of species including non-avian dinosaurs.

End-Permian Extinction

The most severe extinction event in Earth's history, occurring approximately 252 million years ago, where 96% of species went extinct.