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The anomuran morphospace: testing alternative evolutionary pathways and diversification patterns in a highly disparate clade

PI(s): Patricia Cabezas (Brigham Young University (BYU))
Start Date: 14-Nov-2012
End Date: 14-Dec-2012
Keywords: macroevolution, systematics, morphology, speciation, comparative methods

Understanding the uneven diversity of species and morphological traits across the Tree of Life is a major focus in evolutionary biology. The Anomuran decapods provide an unmatched system to tackle this question since they exhibit a remarkable degree of morphological disparity, including body forms ranging from squat-lobsters, asymetrical and symmetrical hermit crabs to king crabs. Its impressive array of body forms, and particularly, its general tendency toward carcinization (acquisition of crab-like form from a non-crab like form) has been noted since the early 1900’s. Contrasting hypotheses have been proposed to explain the origin and evolutionary pathways leading to Anomuran body forms, and recent findings are consistent with the idea that different morphologies are linked with different diversification rates. This project will translate verbal hypotheses into statistical models in order to infer the most probable evolutionary pathway, as well as whether different body forms have evolved under different diversification rates. This macroevolutionary analysis ensures novel insights into a long-standing debate in crustacean systematics, and will provide an empirical framework for evolutionary biologists to interpret morphological change in highly disparate clades.