Scientists believe that life on Earth has changed over time, and that it is still changing. In this module, you will explore the theory of evolution, which is the concept that the organisms on Earth today developed and changed from organisms present in earlier time periods. You will begin by learning how the fossil record supports the idea that life originated in Earth's oceans and moved to land. In addition, you will examine the process of natural selection, which explains how species – including humans – adapt to constant changes in their environments.
Getting Started
Before you begin learning about evolution and the role that natural selection plays in life on Earth, see how many of the related terms and definitions you understand. In this non-graded activity, read the definition, and then drag and drop the term into the blank space provided. Then, click SUBMIT to check your responses. Click the player button to get started.
Key Vocabulary
To view the definitions for these key vocabulary terms, visit the course glossary.
adaptation | evolution | natural selection |
adaptive radiation | extinction | punctuated equilibrium |
analogous structure | fossil record | radiocarbon dating |
bottleneck effect | founder effect | relative dating |
coevolution | gene flow | reproductive isolation |
convergent evolution | genetic drift | speciation |
directional selection | genetic variation | stabilizing selection |
disruptive selection | homologous structure | trace fossil |
divergent evolution | index fossil | vestigial structures |
embryology | mass extinction |