The Origin of Major New Forms of Life

• The origin of mammals

Gradualism and Saltation

The Evolution of Novelty

• Incipient and novel features: Permissive conditions and natural selection
• Complex characteristics
• Homology and the emergence of novel characters

From Microevolution to Macroevolution

• Rates of evolution
• Gradualism and punctuated equilibria
• Speciation and phenotypic evolution

Trends, Predictability, and Progress

• Trends: Kinds and causes
• Are there major trends in the history of life?
• Predictability and contingency in evolution
• The question of progress