title: Phylogenetic analysis using Lévy processes: finding jumps in the evolution of continuous traits.
abstract: Gaussian processes, a class of stochastic processes including Brownian motion and the Ornstein-Uhlenbeck process, are widely used to model continuous trait evolution in statistical phylogenetics. Under such processes, observations at the tips of a phylogenetic tree have a multivariate Gaussian distribution, which may lead to suboptimal model specification under certain evolutionary conditions, as supposed in models of punctuated equilibrium or adaptive radiation. To consider non-normally distributed continuous trait evolution, we introduce a method to compute posterior probabilities when modeling continuous trait evolution as a Lévy process. Through data simulation and model testing, we establish that single-rate Brownian motion (BM) and Lévy processes with jumps generate distinct patterns in comparative data. We then analyzed body mass and endocranial volume measurements for 126 primates. We rejected single-rate BM in favor of a Lévy process with jumps for each trait, with the lineage leading to most recent common ancestor of great apes showing particularly strong evidence against single-rate BM.
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, CA 94720-3140, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Landis
authors.forename: Joshua G
authors.initials: JG
authors.lastname: Schraiber
authors.forename: Mason
authors.initials: M
authors.lastname: Liang
mesh_terms: D000818:Animals; D015992:Body Mass Index; D003198:Computer Simulation; D008954:Models, Biological; D010641:Phenotype; D010802:Phylogeny; D011323:Primates / Q000145:classification / Q000502:physiology