Tree of Life Project
The Tree of Life Web Project
The Tree of Life Web Project contains information on living organisms including their history and characteristics. Over 3,000 web pages are linked together uniting all living things.
Other
Evidence for Evolution: Formation of New Species
These pages are part of a site called Evolution that accompanies a textbook by the same name. Mark Ridley is the author. These pages offer an explanation of speciation using reproductive isolation and differences in phenotype.
American Museum of Natural History
American Museum of Natural History: What Is a "Species"?
Explanation of different scientific approaches to defining the concept of species, using the red crossbill (a seed-eating finch) as an example. Learn what is meant by the biological species concept and the phylogenetic species concept.