TY - JOUR

T1 - Division of labor and recurrent evolution of polymorphisms in a group of colonial animals

AU - Lidgard, Scott

AU - Carter, Michelle C.

AU - Dick, Matthew H.

AU - Gordon, Dennis P.

AU - Ostrovsky, Andrew N.

N1 - Funding Information: Acknowledgments J.B.C. Jackson provided inspiration and cajoling that extend well beyond this paper. M. Hopkins, Field Museum, Chicago, and L.K. Nyhart, University of Wisconsin, Madison, provided useful comments on the manuscript. J.G. Harmelin, Centre d’Océanologie de Marseille, Université de la Médi-terranée, graciously supplied the images in Fig. 4. MCC acknowledges support from a PhD Commonwealth Scholarship, Victoria University of Wellington, and the National Institute of Water & Atmospheric Research, Wellington. ANO thanks FWF, Austria (grant P22696-B17) and the RFBR, Russia (grants 10-04-00085-a, 10-04-10089-r) for financial support. We are grateful to all.

PY - 2012/3

Y1 - 2012/3

N2 - Rendering developmental and ecological processes into macroevolutionary events and trends has proved to be a difficult undertaking, not least because processes and outcomes occur at different scales. Here we attempt to integrate comparative analyses that bear on this problem, drawing from a system that has seldom been used in this way: the co-occurrence of alternate phenotypes within genetic individuals, and repeated evolution of distinct categories of these phenotypes. In cheilostome bryozoans, zooid polymorphs (avicularia) and some skeletal structures (several frontal shield types and brood chambers) that evolved from polymorphs have arisen convergently at different times in evolutionary history, apparently reflecting evolvability inherent in modular organization of their colonial bodies. We suggest that division of labor evident in the morphology and functional capacity of polymorphs and other structural modules likely evolved, at least in part, in response to the persistent, diffuse selective influence of predation by small motile invertebrate epibionts.

AB - Rendering developmental and ecological processes into macroevolutionary events and trends has proved to be a difficult undertaking, not least because processes and outcomes occur at different scales. Here we attempt to integrate comparative analyses that bear on this problem, drawing from a system that has seldom been used in this way: the co-occurrence of alternate phenotypes within genetic individuals, and repeated evolution of distinct categories of these phenotypes. In cheilostome bryozoans, zooid polymorphs (avicularia) and some skeletal structures (several frontal shield types and brood chambers) that evolved from polymorphs have arisen convergently at different times in evolutionary history, apparently reflecting evolvability inherent in modular organization of their colonial bodies. We suggest that division of labor evident in the morphology and functional capacity of polymorphs and other structural modules likely evolved, at least in part, in response to the persistent, diffuse selective influence of predation by small motile invertebrate epibionts.

KW - Bryozoa

KW - Asexual growth

KW - Modularity

KW - Polymorphism

KW - Evolvability

KW - Predation

UR - http://www.scopus.com/inward/record.url?scp=84857442875&partnerID=8YFLogxK

U2 - 10.1007/s10682-011-9513-7

DO - 10.1007/s10682-011-9513-7

M3 - Article

VL - 26

SP - 233

EP - 257

JO - Evolutionary Ecology

JF - Evolutionary Ecology

SN - 0269-7653

IS - 2

ER -