Overview

Brief module summary

Life Has a History is intended to be an introduction to a variety of topics that are important for understanding the history of life and the biodiversity we see today. Because this tour is written at two different learning levels, the learning objectives for each level are described below.

Learning Objectives

Stops along the tour emphasize the following concepts.

For the Level One tour:

• Life has changed during Earth's long history.
• Life is very diverse and always has been.
• Living things come from other living things. Therefore, they are related.
• All related animals have similarities and differences.
• Over a long period of time, differences add up and lead to the formation of new species.
• Some living things from long ago look very different than their relatives today.
• Fossils show us about living things long ago.
• Many groups of living things from the past have disappeared.
• All living things are relate and life continues to change.

For the Level Two tour:

• Life is very diverse and always has been.
• The diversity of life (biodiversity) we have today is a result of evolution.
• Evolution has occurred over billions of years of Earth's history.
• Fossils provide evidence for the evolution of life.
• Fossils help us to identify the relationships among groups of related organisms.
• Related organisms share features inherited from common ancestors.
• Scientists use diagrams called cladograms to show evolutionary relationships.
• The more recently two organisms shared a common ancestor, the more closely related they are.
• Variation is essential for evolution.
• Variation affects how an organism can live and exploit its environment.
• Over time species show change caused by natural selection.
• Natural selection is not the only mechanism of evolution.
• During the course of evolution, only a small percentage of species have survived.
• Though all living things are related through a common ancestry, life continues to change resulting in the biodiversity we see today.

Prerequisites

None. This tour is intended to be an introduction to a variety of topics related to understanding life's history and biodiversity.

To Technical requirements