Showing papers by "Andy Purvis published in 1994"
TL;DR: Simulations show independent contrasts to be valid when branch lengths are known, whether or not the topology is known fully, and how the two approaches stand up to incompletely resolved trees and incorrect branch length information—common situations for comparative biologists.
220 citations
TL;DR: It is concluded that competition may cause species with similar body sizes to reduce geographic range overlap, suggesting that species' distributions are more constrained by niche requirements than competition.
Abstract: 1. The amount of overlap between the geographic ranges of closely related species is thought to depend, in part, on the extent to which similar species share the same habitat requirements and on the degree of competition between them. 2. The amount of overlap between pairs of closely related species is compared with an expected amount, generated using a null model. Two data sets are used: Palearctic mammals and British mammals. 3. Closely related species tend to overlap more than expected by chance, suggesting that species' distributions are more constrained by niche requirements than competition. Species that overlap less than expected are more similar in body size and vice versa, leading to the conclusion that competition may cause species with similar body sizes to reduce geographic range overlap
39 citations