We can't manipulate some stars while maintaining other stars as controls; we can't start and stop ice ages, and we can't experiment with designing and evolving dinosaurs.

F. 2005 Collapse: How Societies Choose to Fail or Succeed. PMID 3762700.

Originally trained in physiology Diamond's work is known for drawing from a variety of fields including anthropology ecology geography and evolutionary biology. He is currently Professor of Geography at the University of California Los Angeles.