Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-23T22:04:21.575Z Has data issue: false hasContentIssue false
  • English
  • Français

Allometry and heterochrony in an Eocene echinoid lineage: morphological change as a by-product of size selection

Published online by Cambridge University Press:  08 February 2016

Michael L. McKinney
Michael L. McKinney*
Affiliation:
Department of Geology and Geophysics, and Peabody Museum of Natural History, Yale University, New Haven, Connecticut, 06511
Get access Rights & Permissions [Opens in a new window]

Abstract

Three closely related species of the irregular echinoid Oligopygus succeed one another in the late Eocene deposits of Florida. This apparent lineage, where each species is similar but larger than the preceding species, offers an excellent opportunity to examine relationships between heterochrony and environmental change. Bivariate and multivariate techniques illustrate patterns of simple and complex allometry and indicate that simple size increase related to changes in the timing of maturation account for most of the morphological differences among species. Those differences that are not the by-products of size increase are due to heterochronic changes dissociated from the otherwise global (i.e., whole organism) hypermorphosis and were probably needed to increase the relative food intake of the larger forms. Unlike the vast majority of allometric studies, which show constant growth ratios, the ontogenies analyzed here often exhibit curvilinear trajectories. Thus, heterochronic events are seen as systematic alterations of already changing growth ratios. It is suggested that these heterochronic changes provided quick, efficient responses to selective pressures on a plurality of characters and behaviors. As the Florida carbonate environment became more stable, responses associated with K-type life history strategies were favored, resulting in “size selection.” Thus, the morphological differentia among these species may not have resulted from selection directed at those traits, but were either simple sequelae of size increase or of changes which occurred to permit the size increase.

Type
Articles
Information
Paleobiology , Volume 10 , Issue 4 , Fall 1984 , pp. 407 - 419
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

Alberch, P. and Alberch, J. 1981. Heterochronic mechanisms of morphological diversification and evolutionary change in the neotropical salamander Bolitoglossa occidentalis (Amphibia: Plethodontidae). J. Morphol. 167:249–264.CrossRefGoogle ScholarPubMed
Alberch, P., Gould, S. J., Oster, G. F., and Wake, D. B. 1979. Size and shape in ontogeny and phylogeny. Paleobiology. 5:296–317.CrossRefGoogle Scholar
BMDP. 1981. BMDP Statistical Software. 724 pp. Univ. of Calif. Press; Berkeley.Google Scholar
Bretsky, P. W. and Lorenz, D. M. 1971. Adaptive response to environmental stability: a unifying concept in paleoecology. Proc. N. Am. Paleontol. Conv., 522–550.Google Scholar
Chen, C. S. 1965. The regional lithostratigraphic analysis of Paleocene and Eocene rocks of Florida. 105 pp. Fla. Geol. Surv. Bull. 45.Google Scholar
Croft, M. 1980. Ecology and stratigraphy of the echinoids of the Ocala Limestone. 128 pp. Unpubl. M.S. thesis; Fla. State Univ.Google Scholar
Eldredge, N. 1982. Phenomenological levels and evolutionary rates. Syst. Zool. 31:338–347.CrossRefGoogle Scholar
Fenk, E. M. 1979. Sedimentology and stratigraphy of Middle and Upper Eocene carbonate rocks, Lake, Hernando, and Levy counties, Florida. 132 pp. Unpubl. M.S. thesis; Univ. Fla.Google Scholar
Gould, S. J. 1966. Allometry and size in ontogeny and phylogeny. Biol. Rev. 41:587–640.CrossRefGoogle ScholarPubMed
Gould, S. J. 1967. Evolutionary patterns in pelycosaurian reptiles: a factor-analytic study. Evolution. 21:385–401.CrossRefGoogle ScholarPubMed
Gould, S. J. 1977. Ontogeny and Phylogeny. 501 pp. Harvard Univ. Press; Cambridge, Mass.Google Scholar
Gould, S. J. 1980. Is a new and general theory of evolution emerging? Paleobiology. 6:119–130.CrossRefGoogle Scholar
Gould, S. J. and Lewontin, R. C. 1979. The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proc. Roy. Soc. Lond. 205B:581–598.Google Scholar
Hull, D. L. 1976. Are species really individuals? Syst. Zool. 25:174–191.Google Scholar
Imbrie, J. 1956. Biometrical methods in the study of invertebrate fossils. Bull. Am. Mus. 108:219–252.Google Scholar
Kier, P. M. 1967. Revision of the oligopygoid echinoids. 149 pp. Smithson. Misc. Coll. Vol. 152.Google Scholar
Lynn, W. G. 1942. The embryology of Eleutherodactylus nubicola, an anuran which has no tadpole stage. Contr. Embryol. 30:27–62.Google Scholar
McKinney, M. L. 1984. Suwannee Channel of the Paleogene Coastal Plain: support for the “carbonate suppression” model of basin formation. Geology. 12:343–345.2.0.CO;2>CrossRefGoogle Scholar
McKinney, M. L. and Jones, D. S. 1983. Oligopygoid echinoids and the biostratigraphy of the Ocala Limestone. Southeastern Geol. 23:21–29.Google Scholar
McKinney, M. L. and Schoch, R. M.In press. Titanothere heterochrony: revising an allometric classic. Evolution.Google Scholar
McNamara, K. J. 1982. Heterochrony and phylogenetic trends. Paleobiology. 8:130–142.CrossRefGoogle Scholar
McNamara, K. J.In press. A guide to the nomenclature of heterochrony. J. Paleontol.Google Scholar
Newell, N. D. 1949. Phyletic size increase—an important trend illustrated by fossil invertebrates. Evolution. 3:103–124.CrossRefGoogle Scholar
Raff, R. A. and Kaufman, T. C. 1983. Embryos, Genes, and Evolution. 394 pp. Macmillan; New York.Google Scholar
Randazzo, A. F. and Saroop, H. C. 1976. Sedimentology and paleoecology of Middle and Upper Eocene carbonate shoreline sequences, Crystal River, Florida, U.S.A. Sed. Geol. 15:259–291.CrossRefGoogle Scholar
Sacher, G. A. 1970. Allometric and factorial analysis of brain structure in insectivores and primates. Pp. 245–287 In: Norback, C. R. and Montagna, W., eds. Advances in Primatology. Vol. 1. 320 pp. Appleton-Century-Crofts; New York.Google Scholar
SAS. 1982. SAS User's Guide. 584 pp. SAS Inst.; Cary, N.C.Google Scholar
Sharpe, C. L. 1980. Sedimentological interpretations of Tertiary carbonate rocks from west central Florida. 170 pp. Unpubl. M.S. thesis; Univ. Fla.Google Scholar
Smith, A. B. 1984. Echinoid Palaeobiology. 190 pp. George Allen & Unwin; Boston.Google Scholar
Stanley, S. M. 1973. An explanation for Cope's Rule. Evolution. 27:1–26.CrossRefGoogle ScholarPubMed
Stanley, S. M. 1979. Macroevolution, Pattern and Process. 332 pp. W. H. Freeman; San Francisco.Google Scholar
Zachos, L. G. 1978. Stratigraphy and petrology of two shallow wells in Citrus and Levy Counties, Florida. 105 pp. Unpubl. M.S. thesis; Univ. Fla.Google Scholar
Zachos, L. G. and McKinney, M. L.In preparation. An echinoid biozonation of Florida, with biofacies from duster analysis.Google Scholar
Zachos, L. G. and Shaak, G. D. 1978. Stratigraphic significance of the Tertiary echinoid Eupatagus ingens Zachos. J. Paleontol. 52:921–927.Google Scholar