23 Evolution of Earth

Study.com College Biology 101

Paleozoic Era

Included the Cambrian explosion Reptiles, insects, and more varieties of advanced plant life appeared Era ended with many land and water organisms becoming extinct

Catastrophism

A theory proposed by George Cuvier that describes evolution as a process following local catastrophic events like floods or fires Events would lead to extinction or adaptation

Adaptation

In the context of evolution, it describes organisms as changing.

Carbon-14

The most common element used in radioactive dating of rocks and fossils

Cenozoic Era

Started after the mass extinction of dinosaurs Mammals, birds, and insects became more diverse Humans developed in this time period Current era

Mesozoic Era

Also called the age of the dinosaurs Plant life was mostly limited to gymnosperms, which are flowerless Ended 66 million years ago with a mass extinction of the dinosaurs

Cambrian Explosion

Occurred during the Paleozoic Era Characterized by an enormous increase in organism population and diversity Included life moving from water to land

Status

In the context of evolution, it describes organisms as staying the same. Occurs when organisms are a good fit for their environment

Evolution

An important concept in biology that describes how organisms change over time

Punctuated Equilibrium

A theory that states that life on Earth evolved with periods of brief and abrupt changes followed by long periods of stability.

Precambrian Era

Started when Earth was formed Production of oxygen by single-celled organisms allowed for evolution of more complex, multicellular organisms such as jellyfish and worms

Gradualism

A theory proposed by James Hutton that describes evolution as a long, gradual, continuous process occurring over time Adaptations in organisms appear slowly over many generations

Mass Extinction

An event occurring between eons or eras that kills off a great amount of living organisms

Adaptive Radiation

A theory that states that organisms that share a common ancestor evolved when they radiated (moved) away from one area and adapted to another Example: finches found on Galapagos Islands