How do minerals collect in ancient bones? Why are fish fossils sometimes found on land? How can some feathers be preserved for millions of years? This series explores the causes and effects that shape our world.

Melissa Stewart earned a bachelor's degree in biology from Union College and a master's degree in science and environmental journalism from New York University. She has written more than thirty books for children and has contributed articles to a variety of magazines for adults and children. In her free time, Melissa enjoys hiking and canoeing near her home in Northborough, MA.