Meeting Abstract

P1.78  Tuesday, Jan. 4  Small Clade Peripheralization in Three Flycatcher Radiations CORBIN, CE*; MILES, DB; Bloomsburg University; Bloomsburg University ccorbin@bloomu.edu

Recently interests in evolutionary morphology are growing. This is especially true for analysis of association between morphological diversity and species diversification. One extension of this analysis is niche, and concomitantly, morphospace filling. As a clade diversifies, do newer lineages or subclades with smaller membership occupy the extremes of the morphological space. Nine morphological measures on species in Tyrannidae, Muscicapidae, and Monarchidae were used to test the small-clade peripheralization hypothesis. Species were grouped into genera and then subsequently into groups (Based on upper 25% quartiles) with large numbers of species (large clades; n=7 or more) and relatively depauperate genera (small clades; n < 7). Statistical analysis included PCA, quadratic regression, and computation of Jackknife Distances to test for peripheralization Outliers were small clades but tended to be distributed throughout the morphospace. Large clades were centralized and had reduced confidence ellipse volume compared to the small clades. Morphological characterization of small relative to large clades was family-level dependent. Hence while superficial morphological similarities exist among flycatcher radiations, morphospace filling seems to be subject to large scale phylogenetic constraint.