The ability of ecologists to identify regions of greatest species richness could have an impact on the preservation of genetic diversity, a major objective of the World Conservation Strategy. The article “Prediction of Rarities from Habitat Variables: Coastal Plain Plants on Nova Scotian Lakeshores” (Ecology [1992]: 1852–

1859) used a sample of n 37 lakes to obtain the estimated regression equation y^ 5 3.89 1 .033x1 1 .024x2 1 .023x3 1 .008x4 2 .13x5 2 .72x6 where y species richness, x1 watershed area, x2 shore width, x3 drainage (%), x4 water color (total color units), x5 sand (%), and x6 alkalinity. The coefficient of multiple determination was reported as R2 .83. Use a test with significance level .01 to decide whether the chosen model is useful.