Meeting Abstract

P3-253  Monday, Jan. 6  Calibrating Empirical Estimates of Theoretical Morphospace: A Phylometricmorphospace Approach STORCH, JD*; HERNANDEZ, LP; The George Washington University, Washington, DC; The George Washington University, Washington, DC jdstorch@gwu.edu

Projections of phylogeny into morphospace i.e. phylomorphospace allow evolutionary relatedness and morphological diversity to be visualized. Positioning tree topologies within spaces produce estimates of branch length measured in units of morphospace distance. Evolutionary relatedness between observations is a source of distance information that is available to most of the biological systems we study. We can use this information to calibrate our perception of morphospace. Warping morphospace around an ultrametric phylogeny results in space that is increasingly traversable along phylogenetic lines of least resistance i.e. phylometricmorphospace. The phylometricmorphospace approach can improve empirical estimates of theoretical morphospace. Incorporating distance-based information about evolutionary relatedness into the construction of phylometricmorphospace increases the informativeness of distance measures within this space, amounting to a phylogenetic correction of regions between point estimates of morphospace occupancy. We explore the behavior of this method using simulation in order to characterize the sensitivity of phylometricmorphospace to misspecification of the tree topology. In this manner, we illuminate properties of the sampling distribution of morphospace occupancy within phylometricmorphospace as structured by the tree topology. We expect a calibrated empirical morphospace to better estimate the “spectrum of possible forms” (sensu Raup) when signals of e.g. convergence and constraint captured in the tree are attenuated by the noise of merely measurable forms in the uncalibrated condition.