1. Home
  2. Education
  3. Animals / Wildlife

Evolution

By , About.com Guide

Definition: Evolution is change over time. Under this broad definition, evolution can refer to a variety of changes that occur over time—the uplifting of mountains, the erosion of riverbeds, or the creation of new species. The term biological evolution is a more specific type of evolution.

Biological evolution refers to the changes over time that occur in living organisms. Biological evolution is defined as descent with modification.

Biological evolution occurs at different scales. These include small-scale evolution and broad-scale evolution. Small-scale evolution, also referred to as microevolution, is the change in gene frequencies within a population of organisms changes from one generation to the next. Broad-scale evolution, also referred to as macroevolution, refers to the progression of species from a common ancestor to descendent species over the course of numerous generations.

Explore Animals / Wildlife

About.com Special Features

A Smarter Future

Tips that will help finance your education, excel in the classroom, and advance your career. More >

How to Ace the GRE

Being well prepared is the first step; here are more essential suggestions. More >

  1. Home
  2. Education
  3. Animals / Wildlife
  4. Zoology Glossary
  5. E
  6. Evolution - Definition of Evolution>

©2009 About.com, a part of The New York Times Company.

All rights reserved.