|
|
 |
Overview
The module is composed of six short chapters, which can be explored in two classroom sessions. The first three chapters provide: an introduction, an examination of the key characteristics that make an arthropod an arthropod, and an exploration of early arthropods and other animals during the Cambrian. This provides students with sufficient background to begin to look at the evolution of arthropods more closely. The last three chapters provide: a look at two of the "tools" for success for arthropods — the exoskeleton and the jointed leg, followed by a look at the constraints that these same traits impose on arthropods evolution, and a conclusion that looks at the diversity of arthropods around us. Students then have the opportunity to complete a Special Assignment that can be used to assess their understanding.
Concepts
During this module students will learn that:
- Life forms of the past were in some ways very different from living forms of today, but in other ways very similar.
- Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry.
- There are similarities and differences among fossils and living organisms.
- The fossil record documents the biodiversity of the past.
- Similarities among existing organisms, combined with evidence in the fossil record, provide evidence for evolution.
- Evolution acts on what exists.
- Inherited traits provide both opportunities and constraints.
Prerequisites
Prior to accessing this module, students should have a grasp of the following:
- Evolutionary trees show how different organisms are related to one another.
- Characteristics are inherited via lines of descent.
- Natural selection is a process that results in adaptation.
Additionally, students should be familiar with cladograms. If they need help with understanding cladograms, have them work through the module, What Did T.rex Taste Like?
|
