Hostname: page-component-78c5997874-lj6df Total loading time: 0 Render date: 2024-11-04T17:44:02.299Z Has data issue: false hasContentIssue false
  • English
  • Français

The disparity of the Burgess Shale arthropod fauna and the limits of cladistic analysis: why we must strive to quantify morphospace

Published online by Cambridge University Press:  08 February 2016

Stephen Jay Gould
Stephen Jay Gould*
Affiliation:
Museum of Comparative Zoology, Harvard University, Cambridge, Massachusetts 02138
Get access Rights & Permissions [Opens in a new window]

Abstract

Three major arguments have been raised against the crucial claim, documented by Whittington and colleagues for the Burgess Shale fauna, and so contrary to traditional views, that disparity of anatomical design reached an early maximum in the history of multicellular life: (1) the presence of many early taxa with low membership and high rank is an artifact of naming; (2) cladistic analysis of Burgess arthropods negates the claim for greater early disparity; and (3) Whittington's argument is a retrospective fallacy based on assigning high rank to differentia only by virtue of their later capacity to define major branches. I show that all these arguments are either false or illogical, and that the claim for increased early disparity is justified: (1) Taxonomic rank is an artifact, but no one has ever based a claim for greater disparity on this false criterion. (2) Cladistics can only deal with branching order, whereas disparity is a phenetic issue. These two legitimate aspects of evolutionary “relationship” are logically distinct. The rooting of a cladogram only illustrates monophyletic ancestry (which no one doubts, as we are not creationists), and cannot measure disparity. (3) The active stabilization of the differentia of Baupläne (for genetic and developmental reasons only dimly understood) provides a powerful rationale for weighting these characters in considerations of disparity; nothing had so stabilized in the Burgess fauna. If these differentia were steadily changing contingencies, rather than actively stabilized features with “deep” architectural status, then the retrospective argument would be justified. Although the three arguments are wrong, the claim for greater early disparity cannot be confidently established until we develop quantitative techniques for the characterization of morphospace and its differential filling through time. This is a dauntingly difficult problem, much harder than cladistic ordering, but not intractable.

Type
Articles
Information
Paleobiology , Volume 17 , Issue 4 , Fall 1991 , pp. 411 - 423
Copyright
Copyright © The Paleontological Society 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Literature Cited

Bard, J. 1990. The fifth day of creation. Bioessays 12:303–306.CrossRefGoogle Scholar
Bengtson, S. 1990. Wonderful life, lovely story. Lethaia 23:115–116.CrossRefGoogle Scholar
Bookstein, F. L. 1977a. Orthogenesis of the hominids: an exploration using biorthogonal grids. Science 197:901–904.CrossRefGoogle ScholarPubMed
Bookstein, F. L. 1977b. The study of shape transformation after D'Arcy Thompson. Mathematical Biosciences 34:177–219.CrossRefGoogle Scholar
Briggs, D.E.G. 1978. The morphology, mode of life, and affinities of Canadaspis perfecta (Crustacean: Phyllocarida), Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 281:439–487.Google Scholar
Briggs, D.E.G., and Collins, D. 1988. A Middle Cambrian chelicerate from Mount Stephen, British Columbia. Palaeontology 31:779–798.Google Scholar
Briggs, D.E.G., and Fortey, R. A. 1989. The early radiation and relationships of the major arthropod groups. Science 246:241–243.CrossRefGoogle ScholarPubMed
Bruton, D. L. 1981. The arthropod Sidneyia inexpectans, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 295:619–656.Google Scholar
Bruton, D. L., and Whittington, H. B. 1983. Emeraldella and Leanchoilia, two arthropods from the Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 300:553–585.Google Scholar
Cherry, L. M., Case, S. M., Kunkel, J. G., and Wilson, A. C. 1979. Comparisons of frogs, humans, and chimpanzees. Science 204:435.CrossRefGoogle ScholarPubMed
Cisne, J. L. 1974. Evolution of the world fauna of aquatic free-living arthropods. Evolution 28:337–366.CrossRefGoogle ScholarPubMed
Darwin, C. 1859. On the Origin of Species. John Murray; London.Google Scholar
Eckhardt, R. B. 1991. Fish scales for human origins. Nature 349:112.CrossRefGoogle ScholarPubMed
Foote, M. 1988. Survivorship analysis of Cambrian and Ordovician trilobites. Paleobiology 24:258–271.CrossRefGoogle Scholar
Fortey, R. A. 1989. The collection connection. Nature 342:303.CrossRefGoogle Scholar
Gould, S. J. 1984. Morphological channeling by structural constraint: convergence in styles of dwarfing and gigantism in Cerion, with a description of two new fossil species and a report on the discovery of the largest Cerion. Paleobiology 10:172–194.CrossRefGoogle Scholar
Gould, S. J. 1989. Wonderful Life. W. W. Norton and Company; New York.Google Scholar
Hennig, W. 1966. Phylogenetic Systematics. University of Illinois Press; Urbana, Illinois.Google Scholar
Huxley, J. S. 1932. Problems of Relative Growth. MacVeagh; London.Google Scholar
Raup, D. M. 1965. Theoretical morphology of the coiled shell. Science 147:1294–1295.CrossRefGoogle ScholarPubMed
Raup, D. M. 1966. Geometric analysis of shell coiling: general problems. Journal of Paleontology 40:1178–1190.Google Scholar
Raup, D. M. 1967. Geometric analysis of shell coiling: coiling in ammonoids. Journal of Paleontology 41:43–65.Google Scholar
Raup, D. M. 1968. Theoretical morphology of echinoid growth. Journal of Paleontology 42:50–63.CrossRefGoogle Scholar
Ridley, M. 1990. Dreadful beasts. The London Review of Books, June 28, pp. 11–12.Google Scholar
Riedl, R. 1978. Order in Living Organisms. John Wiley and Sons; New York.Google Scholar
Robison, R. A. 1985. Affinities of Aysheaia (Onychophora) with description of a new Cambrian species. Journal of Paleontology 59:226–235.Google Scholar
Rolfe, W.D.I. 1990. Life: a loser's manual. The Scotsman, February 10, p. 8.Google Scholar
Schank, J. C., and Wimsatt, W. C. 1986. Generative entrenchment and evolution. Philosophy of Science Association 2:33–60.Google Scholar
Simpson, G. G. 1953. The Major Features of Evolution. Columbia University Press; New York.CrossRefGoogle Scholar
Sneath, P.H.A. 1967. Trend-surface analysis of transformation grids. Proceedings of the Zoological Society of London 151:65–122.CrossRefGoogle Scholar
Sneath, P.H.A., and Sokal, R. R. 1973. Numerical taxonomy. W. H. Freeman and Company; San Francisco.Google Scholar
Stormer, L. 1959. Trilobitoidea. Pp. 23–37. In Moore, R. C. (ed.), Treatise on Invertebrate Paleontology, Arthropoda I. Geological Society of America; New York.Google Scholar
Thompson, D. W. 1917. On Growth and Form. Macmillan; London.CrossRefGoogle Scholar
Walcott, C. D. 1912. Middle Cambrian Branchiopoda, Malacostraca, Trilobita and Merostomata. Cambrian Geology and Paleontology, II. Smithsonian Miscellaneous Collections 57:145–228.Google Scholar
Whittington, H. B. 1971. Redescription of Marrella splendens (Trilobitoidea) from the Burgess Shale, Middle Cambrian, British Columbia. Geological Survey of Canada Bulletin 209:1–24.Google Scholar
Whittington, H. B. 1974. Yohoia Walcott and Plenocaris n. gen., arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Geological Survey of Canada Bulletin 231:1–21.Google Scholar
Whittington, H. B. 1975. Trilobites with appendages from the Middle Cambrian, Burgess Shale, British Columbia. Fossils and Strata (Oslo) 4:97–136.CrossRefGoogle Scholar
Whittington, H. B. 1977. The Middle Cambrian trilobite Naraoia, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 280:409–443.Google Scholar
Whittington, H. B. 1978. The lobopod animal Aysheaia pedunculata Walcott, Middle Cambrian, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 284:165–197.Google Scholar
Whittington, H. B. 1981. Rare arthropods from the Burgess Shale, Middle Cambrian, British Columbia. Philosophical Transactions of the Royal Society, London B 292:329–357.Google Scholar
Whittington, H. B. 1985. The Burgess Shale. Yale University Press; New Haven.Google Scholar
Whittington, H. B., and Briggs, D.E.G. 1985. The largest Cambrian animal, Anomalocaris, Burgess Shale, British Columbia. Philosophical Transactions of the Royal Society, London B 309:569–609.Google Scholar
Whittington, H. B., and Conway Morris, S. 1985. Extraordinary fossil biotas: their ecological and evolutionary significance. London: Royal Society. Published originally in Philosophical Transactions of the Royal Society, London B 311:1–192.Google Scholar
Wilson, A. C., Kunkel, J. G., and Wyles, S. J. 1984. Morphological distance: an encounter between two perspectives in evolutionary biology. Evolution 38:1156–1159.CrossRefGoogle ScholarPubMed
Wimsatt, W. C., and Schank, J. C. 1988. Two constraints on the evolution of complex adaptations and the means for their avoidance. Pp. 231–273. In Nitecki, M. H. (ed.), Evolutionary Progress. University of Chicago Press; Chicago.Google Scholar
Wyles, J. S., Kunkel, J. G., and Wilson, A. C. 1983. Birds, behavior, and anatomical evolution. Proceedings of the National Acadamy of Sciences 80:4394–4397.CrossRefGoogle ScholarPubMed