Rahbek and Graves stated that "topography, precipitation, ... ecosystem diversity, and cloud cover emerged as the most important predictors of regional variability of species richness..." What were the replicates in their study, and what was the dependent variable? Suppose these four variables together explain 70% of the variance. What does it mean to state that certain variables explain a certain amount of the variance? Can each of the four variables explain a certain percent of the variance on their own? Do these amounts have to add up to 70%? Why or why not? Where did Rahbek and Graves find peak diversity?
List some temperate-tropical plant family pairs. What are the main patterns of growth form and diversity exhibited by these pairs? Why do some botanists want to combine the family pairs into single more inclusive families?
Richardson et al. present a molecular phylogeny of the genus Inga. What family is Inga in? What is a phylogeny? What is the difference between a molecular and morphological phylogeny? Did their results support the time-stability hypothesis of tropical diversity? Why or why not?
John T. Longino, The Evergreen State College, Olympia WA 98505 USA. longinoj@evergreen.edu
Paul Butler, The Evergreen State College, Olympia WA 98505 USA. butlerp@evergreen.edu
Last modified: 5 February 2002