Evidence of Evolution

This illustration of the three domains of life is like a family tree. The branches that are very far apart are not very similar. Branches that are near each other indicate closely related groups.
Click on image for full size
Windows to the Universe original image

What Is Evolution?

Evolution is the process of change through time. Many things evolve. Language evolves so that English spoken four hundred years ago during the time of playwright Shakespeare was very different than English spoken today. Technology evolves over time as new things are invented and modified. Scientific theories evolve as more data are collected and analyses are done. Life evolves over very long timescales as species change over many, many generations. This is called biological evolution. Evolution is the foundation for the modern sciences of paleontology (the study of fossils and the history of life), ecology (the study of ecosystems), and biology (the study of life) including medical science.

  • On a small scale, biological evolution is called microevolution and involves changes in the occurance of gene types in a population of the same species over several generations. These changes can lead to changes in the way a species looks over generations.
  • On a large scale, biological evolution is called macroevolution and involves the development of new species through cumulative genetic changes over many, many generations.

This Windows to the Universe Exploratour examines the scientific evidence for biological evolution. Click the “forward” button at the top of this page to continue the tour and learn more about the scientific basis of evolution.

Last modified May 15, 2009 by Jennifer Bergman.

You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Evolution Impacts Environment, Study Finds

Biologists have long known that ecology, the interaction between organisms and their environment, plays a significant role in forming new species and in modifying living ones. The traditional view is that...more

Missing Link Between Whales and Four-Footed Ancestors Discovered

Scientists have discovered the missing link between whales and their four-footed ancestors. The result is reported in this week's issue of the journal Nature. The research is funded by the National Science...more

A Single Boulder May Prove that Antarctica and North America Were Once Connected

A lone granite boulder found against all odds high atop a glacier in Antarctica may provide additional key evidence to support a theory that parts of the southernmost continent once were connected to North...more

Scientists Find Signs of “Snowball Earth” Amidst Early Animal Evolution

Geologists have found evidence that sea ice extended to the equator 716.5 million years ago, bringing new precision to a "snowball Earth" event long suspected to have taken place around that time. Funded...more

Evolution

Evolution is the process of change through time. Many things evolve. Language evolves so that English spoken four hundred years ago during the time of playwright Shakespeare was very different than English...more

ExploraTour - Looking at the World in a Different Light

Even though the sleeping man is no longer on the bed, you can still see where he was lying down. The heat from his body warmed up the bed sheets which are now radiating infrared light toward your eyes....more

ExploraTour - Looking at the World in a Different Light

All warm objects radiate in the infrared. The warmer the object, the higher the frequency and intensity of the radiation. Very hot objects give off other types of radiation in addition to infrared. Click...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA