The tutorial considers a series of points about adaptation. We look first at the argument to show that natural selection is the only known explanation of adaptation; and second at whether natural selection can explain all adaptations, including such complex organs as the eye. We then look at two definitions of adaptation, in terms of historical and modern factors. The rest of the tutorial deals with various adaptive constraints: why adaptations may not be perfect.

Key Questions:

• Are there explanations for adaptation other than natural selection?
• Can natural selection explain all known adaptations?
• Why is the study of adaptation difficult?
• How do we study adaptations?
• Can an organ change its function without changing structure?
• Is it always appropriate to describe characters as adaptations?
• Is perfect adaptation possible?
• Is there sometimes a trade-off between different adaptive needs?
• How can we recognize adaptations?
• Summary