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Quantifying morphological change during an evolutionary radiation of Devonian trilobites

  • Francine R. Abe (a1) and Bruce S. Lieberman (a2)


The fossil record provides an important source of data on adaptive radiations, and indeed some of the earliest theoretical insights on the nature of these radiations were made by paleontologists. Here we focus on the diverse Devonian Metacryphaeus group calmoniid trilobites, known from the Malvinokaffric Realm, which have been considered a classic example of an adaptive radiation preserved in the fossil record. We use a geometric morphometric analysis in conjunction with phylogenetic and biogeographic patterns and data on speciation rates. Using ancestral character state reconstruction during speciation events, we quantify patterns of morphological change in order to assess the role ecological and geographical factors may have played in mediating this radiation. We found no significant differences between the amount of morphological change that occurred during speciation events when ancestors and descendants were in the same area as opposed to when they occupied different areas. Further, the magnitude of morphological divergence did not change through time or with cladogenetic rank. These patterns, in conjunction with the fact that the radiation occurs in a geographically heterogeneous region subjected to repeated episodes of sea-level rise and fall, suggest that at the macroevolutionary scale this radiation may have been motivated more by phenomena that facilitated geographic isolation than by competition.



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Abe, F., and Lieberman, B. 2009. The nature of evolutionary radiations: a case study involving Devonian trilobites. Evolutionary Biology 36:225234.
Baldis, B. A., and Longobucco, M. 1977. Trilobites devónicos de la Precordillera noroccidental (Argentina). Ameghiniana 14:145161.
Bambach, R., Bush, A., and Erwin, D. 2007. Autecology and the filling of ecospace: key metazoan radiations. Paleontology 50:122.
Bookstein, F. L. 1989. Principal warps: thin-plate splines and the decomposition of deformation. IEEE Transactions on Pattern Analysis and Machine Intelligence 11:567585.
Bookstein, F. L. 1991. Morphometric tools for landmark data: geometry and biology. Cambridge University Press, New York.
Boucot, A. J., and Racheboeuf, P. R. 1993. Biogeographic summary of the Malvinokaffric realm Silurian and Devonian fossils. Revista Tecnica de Yacimientos Petroliferos Fiscales Bolivianos 13–14((1–4)):7175.
Cameron, R. A. D., Cook, L. M., and Hallows, J. D. 1996. Land snails on Porto Santo: adaptive and non-adaptive radiation. Philosophical Transactions of the Royal Society of London B 351:309327.
Carvalho, M. G. P. 2006. Devonian trilobites from the Falkland Islands. Paleontology 49:2134.
Carvalho, M. G. P., Edgecombe, G. D., and Lieberman, B. S. 1997. Devonian calmoniid trilobites from the Parnaíba Basin, Piauí State, Brazil. American Museum Novitates 3192:111.
Carvalho, M. G. P., Edgecombe, G. D., and Smith, L. 2003. New calmoniid trilobites (Phacopina, Acastoidea) from the Devonian of Bolivia. American Museum Novitates 3407:117.
Clabaut, C., Bunje, P. M. E., Salzburger, W., and Meyer, A. 2007. Geometric morphometric analyses provide evidence for the adaptive character of the Tanganyikan cichlid fish radiations. Evolution 61:560578.
Cooper, M. 1982. A revision of the Devonian (Emsian-Eifelian) Trilobita from the Bokkeveld Group of South Africa. Annals of the South African Museum 89:1174.
Cunningham, C., Omland, K., and Oakley, T. 1998. Reconstructing ancestral character states: a critical reappraisal. Trends in Ecology and Evolution 13:361366.
Edgecombe, G. D. 1994. Calmoniid trilobites from the Devonian Fox Bay Formation, Falkland Islands; systematics and biogeography. New York State Museum Bulletin (1976) 481:5568.
Edgecombe, G. D., Vaccari, N. E., and Waisfeld, B. G. 1994. Lower Devonian calmoniid trilobites from the Argentine Precordillera; new taxa of the Bouleia group, and remarks on the tempo of calmoniid radiation. Geological Magazine 131:449464.
Eldredge, N. 1971. Patterns of cephalic musculature in the Phacopina (Trilobita) and their phylogenetic significance. Journal of Paleontology 45:5267.
Eldredge, N., and Branisa, L. 1980. Calmoniid trilobites of the Lower Devonian Scaphiocoelia Zone of Bolivia, with remarks on related species. Bulletin of the American Museum of Natural History 165:181290.
Eldredge, N., and Cracraft, J. 1980. Phylogenetic patterns and the evolutionary process: method and theory in comparative biology. Columbia University Press, New York.
Eldredge, N., and Ormiston, A. R. 1979. Biogeography of Silurian and Devonian trilobites of the Malvinokaffric realm. Pp. 147167inGray, J.and Boucot, A. J., eds. Historical biogeography, plate tectonics, and the changing environment. Oregon State University Press, Corvallis.
Engelmann, G. F., and Wiley, E. O. 1977. The place of ancestor-descendant relationships in phylogeny reconstruction. Systematic Zoology 26:111.
Erwin, D. 1992. A preliminary classification of evolutionary radiations. Historical Biology 6:133147.
Erwin, D. 2007. Disparity: morphological pattern and developmental context. Paleontology 50:5773.
Esselstyn, J. A., Timm, R. M., and Brown, R. M. 2009. Do geological or climatic processes drive speciation in dynamic archipelagos? The tempo and mode of diversification in southeast Asian shrews. Evolution 63:25952610.
Foote, M. 1989. Perimeter-based Fourier analysis; a new morphometric method applied to the trilobite cranidium. Journal of Paleontology 63:880885.
Foote, M. 1990. Nearest-neighbor analysis of trilobite morphospace. Systematic Zoology 39:371382.
Foote, M. 1991. Morphologic patterns of diversification: examples from trilobites. Paleontology 34:461485.
Foote, M. 1993. Contributions of individual taxa to overall morphological disparity. Paleobiology 19:403419.
Foote, M. 1997. Sampling, taxonomic description, and our evolving knowledge of morphological diversity. Paleobiology 23:181206.
Foote, M., and Raup, D. 1996. Fossil preservation and the stratigraphic ranges of taxa. Paleobiology 22:121140.
Fortey, R., and Owens, R. 1990. Evolutionary radiations in the Trilobita. Pp. 139164inTaylor, P.and Larwood, G., eds. Major evolutionary radiations. Oxford University Press, New York.
Genner, M. J., Knight, M. E., Haesler, M. P., and Turner, G. F. 2010. Establishment and expansion of Lake Malawi rock fish populations after a dramatic Late Pleistocene lake level rise. Molecular Ecology 19:170182.
Gillespie, R. G. 2005. Geographical context of speciation in a radiation of Hawaiian Tetragnatha spiders (Araneae, Tetragnathidae). Journal of Arachnology 33:313322.
Gittenberger, E. 1991. What about non-adaptive radiation? Biological Journal of the Linnean Society 43:263272.
Glor, R. E., Gifford, M. E., Larson, A., Losos, J. B., Rodriguez-Schettino, L., Lara, A. R. C., and Jackman, T. R. 2004. Partial island submergence and speciation in an adaptive radiation: a multilocus analysis of the Cuban green anoles. Proceedings of the Royal Society of London B 271:22572265.
Gould, S. 1990. Wonderful life: the Burgess Shale and the nature of history. W. W. Norton, New York.
Grant, P. R. 1999. Ecology and evolution of Darwin's finches. Princeton University Press, Princeton, N.J..
Grant, P. R., and Grant, B. R. 2007. How and why species multiply: the radiation of Darwin's finches. Princeton University Press, Princeton, N.J..
Hallam, A. 1992. Phanerozoic sea-level changes. Columbia University Press, New York.
Harmon, L. J., Schulte, J. A. II, Larson, A., and Losos, J. B. 2003. Tempo and mode of evolutionary radiation in iguanian lizards. Science 301:961964.
Harmon, L. J., Losos, J. B., Davies, T. J., Gillespie, R. G., Gittleman, J. L., Jennings, W. B., Kozak, K. H., McPeek, M. A., Moreno-Roark, F., Near, T. J., Purvis, A., Ricklefs, R. E., Schluter, D., Schulte, J. A. II, Seehausen, O., Sidlauskas, B. L., Torres-Carvajal, O., Weir, J. T., and Mooers, A. O. 2010. Early bursts of body size and shape evolution are rare in comparative data. Evolution 64:23852396.
House, M. R., and Gradstein, F. M. 2004. The Devonian Period. Pp. 202221inGradstein, F. M., Ogg, J. G., and Smith, A. G., eds. A geologic time scale 2004. Cambridge University Press, Cambridge.
Hulbert, R. C. Jr, 1993. Taxonomic evolution in North American Neogene horses (subfamily Equinae): the rise and fall of an adaptive radiation. Paleobiology 19:216234.
Irschick, D., and Losos, J. 1998. A comparative analysis of the ecological significance of maximal locomotor performance in Caribbean Anolis lizards. Evolution 52:219226.
Isaacson, P. A., and Sablock, P. E. 1988. Devonian system in Bolivia, Peru, and northern Chile. Pp. 719728inMcMillan, N. J., Embry, A. F., and Glass, D. J., eds. Devonian of the world. Canadian Society of Petroleum Geologists, Calgary.
Johnson, J. G., Klapper, G., and Sandberg, C. A. 1985. Devonian eustatic fluctuations in Euramerica. Bulletin of the Geological Society of America 96:567587.
Kaufmann, B. 2006. Calibrating the Devonian time scale: a synthesis of U-Pb ID-TIMS ages and conodont stratigraphy. Earth-Science Reviews 76:175190.
Kozak, K. H., Weisrock, D. W., and Larson, A. 2006. Rapid lineage accumulation in a non-adaptive radiation: phylogenetic analysis of diversification rates in eastern North American woodland salamanders (Plethodontidae: Plethodon). Proceedings of the Royal Society of London B 273:539–46.
Lack, D. 1947. Darwin's finches. Cambridge University Press, New York.
Lieberman, B. S. 1993. Systematics and biogeography of the “Metacryphaeus group” Calmoniidae (Trilobita, Devonian) with comments on adaptive radiations and the geological history of the Malvinokaffric realm. Journal of Paleontology 67:549570.
Lieberman, B. S. 2000. Paleobiogeography. Kluwer Academic, New York.
Lieberman, B. S., and Eldredge, N. 1996. Trilobite biogeography in the Middle Devonian: geological processes and analytical methods. Paleobiology 22:6679.
Lieberman, B. S., Edgecombe, G. D., and Eldredge, N. 1991. Systematics and biogeography of the “Malvinella group,” Calmoniidae (Trilobita, Devonian). Journal of Paleontology 65:824843.
Losos, J. B., Jackman, T. R., Larson, A., De Queiroz, K., and Rodriguez-Schettino, L. 1998. Contingency and determinism in replicated adaptive radiations of island lizards. Science 279:21152118.
Losos, J. B., Glor, R. E., Kolbe, J. J., and Nicholson, K. 2006. Adaptation, speciation, and convergence: a hierarchical analysis of adaptive radiation in Caribbean Anolis lizards. Annals of the Missouri Botanical Garden 93:2433.
Maddison, W. 1991. Squared-change parsimony reconstructions of ancestral states for continuous-valued characters on a phylogenetic tree. Systematic Zoology 40:304314.
Maddison, W., and Maddison, D. 2010. Mesquite: a modular system for evolutionary analysis, Version 2.73.
Mahler, D. L., Revell, L. J., Glor, R. E., and Losos, J. B. 2010. Ecological opportunity and the rate of morphological evolution in the diversification of Greater Antillean anoles. Evolution 64:27312745.
McGhee, G. 1996. The late Devonian mass extinction: the Frasnian/Famennian crisis. Columbia University Press, New York.
Oakley, T., and Cunningham, C. 2000. Independent contrasts succeed where ancestor reconstruction fails in a known bacteriophage phylogeny. Evolution 54:397405.
Olson, M. E., and Arroyo-Santos, A. 2009. Thinking in continua: beyond the ‘adaptive radiation’ metaphor. Bioessays 31:13371346.
Osborn, H. 1902. The law of adaptive radiation. American Naturalist 36:353363.
Paul, C. 1992. The recognition of ancestors. Historical Biology 6:239250.
Pereira Soares, S., Simoes, M. G., and de Moraes Leme, J. 2008. Metacryphaeus rotundatus, um novo elemento da fauna de trilobites Calmoniidae (Phacopida), da Formacao Ponta Grossa (Devoniano), Bacia do Parana, Brasil. Geologia USP: Serie Cientifica 8(1):1524.
Petren, K., Grant, P., Grant, B., and Keller, L. 2005. Comparative landscape genetics and the adaptive radiation of Darwin's finches: the role of peripheral isolation. Molecular Ecology 14:29432957.
Phillimore, A. B., and Price, T. D. 2008. Density-dependent cladogenesis in birds. PLoS Biology 6(3):e71.
Polly, P. 2001. Paleontology and the comparative method: ancestral node reconstructions versus observed node values. American Naturalist 157:596609.
Rode, A. L., and Lieberman, B. S. 2004. Using GIS to unlock the interactions between biogeography, environment, and evolution in Middle and Late Devonian brachiopods and bivalves. Palaeogeography, Palaeoclimatology, Palaeoecology 211:345359.
Rohlf, J. 2010a. TPSDig2, Version 2.16. Department of Ecology and Evolutionary Biology, SUNY, Stony Brook, N.Y..
Rohlf, J. 2010b. TPSRelw, Version 1.49. Department of Ecology and Evolution, SUNY, Stony Brook, N.Y..
Rueber, L., Verheyen, E., Sturmbauer, C., and Meyer, A. 1998. Lake level fluctuations and speciation in rock-dwelling cichlid fish in Lake Tanganyika, East Africa. Pp. 225240inGrant, P. R., ed. Evolution on islands. Oxford University Press, Oxford.
Rundell, R. J., and Price, T. D. 2009. Adaptive radiation, nonadaptive radiation, ecological speciation and nonecological speciation. Trends in Ecology and Evolution 24:394399.
Schluter, D. 2000. The ecology of adaptive radiation. Oxford University Press, Oxford.
Shaw, A. B. 1957. Quantitative trilobite studies II. Measurement of the dorsal shell of non-agnostidean trilobites. Journal of Paleontology 31:193207.
Sheets, H. D. 2002. IMP Software, Version 1/17/02. Department of Physics, Canisius College, Buffalo, N.Y..
Simpson, G. G. 1944. Tempo and mode in evolution. Columbia University Press, New York.
Simpson, G. G. 1953. The major features of evolution. Columbia University Press, New York.
Smith, A. B. 1994. Systematics and the fossil record: documenting evolutionary patterns. Blackwell, Oxford.
Smith, L., and Lieberman, B. 1999. Disparity and constraint in olenelloid trilobites and the Cambrian radiation. Paleobiology 459470.
Struve, W. 1959. Calmoniidae. Pp. O483O489inMoore, R. C.Arthropoda 1. Part O of R. C. Moore, ed. Treatise on invertebrate paleontology. Geological Society of America, New York and University of Kansas Press, Lawrence.
Sturmbauer, C., Baric, S., Salzburger, W., Ruber, L., and Verheyen, E. 2001. Lake level fluctuations synchronize genetic divergences of cichlid fishes in African lakes. Molecular Biology and Evolution 18:144154.
Tucker, R. D., Bradley, D. C., Ver Straeten, C. A., Harris, A. G., Ebert, J. R., and McCutcheon, S. R. 1998. New U-Pb zircon ages and the duration and division of Devonian time. Earth and Planetary Science Letters 158:175186.
Vaccari, N. E., Waisfeld, B. G., and Edgecombe, G. D. 1994. Calmoniid trilobites of the Lower Devonian Scaphiocoelia zone in the Argentine Precordillera. Geobios 27:591608.
Vrba, E. 1992. Mammals as a key to evolutionary theory. Journal of Mammalogy 73:128.
Wagner, P. 1995. Testing evolutionary constraint hypotheses with early Paleozoic gastropods. Paleobiology 21:248272.
Wagner, P. 2000. Exhaustion of morphologic character states among fossil taxa. Evolution 54:365386.
Wagner, P., and Erwin, D. 2006. Patterns of convergence in general shell form among Paleozoic gastropods. Paleobiology 32:316337.
Webber, A. J.and Hunda, B. R. 2007. Quantitatively comparing morphological trends to environment in the fossil record (Cincinnatian Series, Upper Ordovician). Evolution 61:14551465.
Webster, A., and Purvis, A. 2002. Testing the accuracy of methods for reconstructing ancestral states of continuous characters. Proceedings of the Royal Society of London B 269:143149.
Webster, M., and Zelditch, M. 2005. Evolutionary modifications of ontogeny: heterochrony and beyond. Paleobiology 31:354372.
Whittington, H. 1997. The trilobite body. Pp. O530inMoore, R. C.Arthropoda 1, Trilobita. Part O of R. C. Moore, ed. Treatise on invertebrate paleontology. Geological Society of America, New York and University of Kansas, Lawrence.
Wills, M., Briggs, D., and Fortey, R. 1994. Disparity as an evolutionary index: a comparison of Cambrian and Recent arthropods. Paleobiology 20:93130.
Wolfart, R. 1968. Die Trilobiten aus dem Devon Boliviens und ihre Bedeutung für stratigraphie und tiergeographie. Beiträge zur Kenntnis des devon von Bolivien. Beihefte zum Geologischen Jahrbuch 74:5241.
Yoder, J., Clancey, E., Des Roches, S., Eastman, J., Gentry, L., Godsoe, W., Hagey, T., Jochimsen, D., Oswald, B., and Robertson, J. 2010. Ecological opportunity and the origin of adaptive radiations. Journal of Evolutionary Biology 23:15811596.
Zelditch, M., and Fink, W. 1996. Heterochrony and heterotopy: stability and innovation in the evolution of form. Paleobiology 22:241254.
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