This is a new series exploring the theories and facts behind the key science concepts. It examines some of the most important concepts of science. Each comprehensive title explains the theories and facts that define a different scientific concept in a clear, concise manner while revealing the history of how each theory was developed. Although often debated, these great theories of geology, biology and physics have become cornerstones of science. This book includes: Bibliography, Index, Diagrams, Timeline, Glossary, Biographies, Further reading list, and Websites.