Person:

Arnold, C

Many questions in comparative biology require that new data be collected, either to build a comparative database for the first time or to augment existing data. Given resource limitations in collecting data, the question arises as to which species should be studied to increase the size of comparative data sets. By taking hypotheses, existing data relevant to the hypotheses, and a phylogeny, we show that a method of “phylogenetic targeting” can systematically guide data collection while taking into account potentially confounding variables and competing hypotheses. Phylogenetic targeting selects potential candidates for future data collection, using a flexible scoring system based on differences in pairwise comparisons. We used simulations to assess the performance of phylogenetic targeting, as compared with the less systematic approach of randomly selecting species (as might occur when data have been collected without regard to phylogeny and variation in the traits of interest). The simulations revealed that phylogenetic targeting increased the statistical power to detect correlations and that power increased with the number of species in the tree, even when the number of species studied was held constant. We also developed a Web‐based computer program called PhyloTargeting to implement the approach (http://phylotargeting.fas.harvard.edu).

The comparative method plays a central role in efforts to uncover the adaptive basis for primate behaviors, morphological traits, and cognitive abilities.[1-4] The comparative method has been used, for example, to infer that living in a larger group selects for a larger neocortex,[5][6] that primate territoriality favors a longer day range relative to home range size,[7] and that sperm competition can account for the evolution of primate testes size.[8][9] Comparison is fundamental for reconstructing behavioral traits in the fossil record, for example, in studies of locomotion and diet.[10-13] Recent advances in comparative methods require phylogenetic information,[2][14-16] but our knowledge of phylogenetic information is imperfect. In the face of uncertainty about evolutionary relationships, which phylogeny should one use? Here we provide a new resource for comparative studies of primates that enables users to run comparative analyses on multiple primate phylogenies Importantly, the 10,000 trees that we provide are not random, but instead use recent systematic methods to create a plausible set of topologies that reflect our certainty about some nodes on the tree and uncertainty about other nodes, given the dataset. The trees also reflect uncertainty about branch lengths.