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Environmental versus genetic causes of morphologic variability in bryozoan colonies from the deep sea

Published online by Cambridge University Press:  08 February 2016

Thomas J. M. Schopf*
Affiliation:
Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois 60637; and Marine Biological Laboratory, Woods Hole, Massachusetts 02543

Abstract

Bryozoans are colonial animals and this permits the partitioning of their morphologic variability into components of within colony (i.e. within a single genotype) and between colony (i.e. between genotype) variance. These data have been obtained for four species of the endemic deep-sea genus Euginoma for a series of characters. In 8 comparisons, one component of the total variance dominated at the 5% level. Population (between colony) variance contributed significantly to the total variance in 63% of the comparisons (5 of 8); individual (within colony) variance contributed significantly to the total variance in 37% of the comparisons (3 of 8).

Compared to shallow water species, the surprising feature of the deep-sea data is that the between colony component of variance is as high as it is. Possibly in the more stable, deep-sea environment, the genotypic contribution to the variance of each individual colony is expressed to a greater degree than in the more variable, shallow water regime. If so, then analyses of variability in colonial animals may be an independent means of ascertaining stability gradients in the fossil record.

Type
Research Article
Copyright
Copyright © The Paleontological Society 

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References

Literature Cited

Bretsky, P. W. and Lorenz, D. M. 1969. Adaptive response to environmental stability: a unifying concept in paleoecology. Proc. N. Am. Paleontol. Conv. E:522550.Google Scholar
Boardman, R. S. and Cheetham, A. H. 1969. Skeletal growth, intracolony variation, and evolution in Bryozoa: a review. J. Paleontol. 43:205233.Google Scholar
Boardman, R. S., Cheetham, A. H., and Cook, P. L. 1970. Intracolony variation and the genus concept in Bryozoa. North Am. Paleontol. Convention, Chicago, 1969, Proc. C:294320.Google Scholar
Calvet, L. 1906. Bryozoaires. Expéditions scientifiques du Travailleur et du Talisman. pp. 355495. Masson et C1e, Publ.; Paris.Google Scholar
Cheetham, A. H. 1962. The polyzoan genus Ditaxiporina Stach. Annu. Mag. Nat. Hist. Ser. 13. 5:485490.CrossRefGoogle Scholar
Cheetham, A. H. 1966. Cheilostomatous polyzoa from the Upper Bracklesham beds (Eocene) of Sussex. Br. Mus. (Nat. Hist.) Bull. Geol. 13(1):1115.Google Scholar
Farmer, J. D. and Rowell, A. J. 1973. Variation in the Bryozoan Fistulipora decorata (Moore and Dudley) from the Beil Limestone of Kansas. pp. 377394. In: Boardman, R. S., Cheetham, A. H., and Oliver, W. A. Jr., eds. Animal Colonies. Dowden, Hutchinson and Ross, Inc.; Stroudsburg, Pa.Google Scholar
Gooch, J. L. and Schopf, T. J. M. 1973. Genetic variability in the deep sea: relation to environmental variability. Evolution 26:545552.CrossRefGoogle Scholar
Jullien, J. 1883. Dragages du Travailleur: Bryozoaires. Bull. Soc. Zool. France, pour 1882. pp. 497529.Google Scholar
Lagaaij, R. 1963. New additions to the Bryozoan fauna of the Gulf of Mexico. Publ. Inst. Mar. Sci., Tex. 9:162236.Google Scholar
Sanders, H. L. and Hessler, R. R. 1969. Ecology of the deep-sea benthos. Science. 163:14191424.CrossRefGoogle ScholarPubMed
Sanders, H. L., Hessler, R. R., and Hampson, G. R. 1965. An introduction to the study of deep-sea benthic fauna assemblages along the Gay Head–Bermuda transect. Deep-Sea Res. 12:845867.Google Scholar
Schopf, T. J. M. 1972. Varieties of paleobiologic experience. pp. 825. In: Schopf, T. J. M., ed. Models in Paleobiology. Freeman, Cooper & Co.; San Francisco, Calif.Google Scholar
Schopf, T. J. M. 1973. Ergonomics of polymorphism: its relation to the colony as the unit of natural selection in species of the Phylum Ectoprocta. pp. 247294. In: Boardman, R. S., Cheetham, A. H., and Oliver, W. A. Jr., eds. Animal Colonies. Dowden, Hutchinson and Ross, Inc.; Stroudsburg, Pa.Google Scholar
Schopf, T. J. M. and Dutton, A. R. 1976. Parallel clines in morphologic and genetic differentiation in a coastal zone marine invertebrate: the bryozoan Schizoporella errata. Paleobiology. 2: in press.CrossRefGoogle Scholar
Siegel, S. 1956. Nonparametric Statistics. 312 pp. McGraw-Hill Book Co., Inc.; New York, N.Y.Google Scholar
Simpson, G. G., Roe, A., and Lewontin, R. C. 1960. Quantitative Zoology. 440 pp. Harcourt, Brace & World, Inc.; New York, N.Y.Google Scholar
Smith, K. L. and Teal, J. M. 1973. Deep-sea benthic community respiration: an in situ study at 1850 meters. Science. 179:282283.CrossRefGoogle Scholar
Turekian, K. K., Cochran, J. K., Kharkar, D. P., Cerrato, R. M., Vaišnys, J. R., Sanders, H. L., Grassle, J. F., and Allen, J. A. 1975. Slow growth rate of a deep-sea clam determined by 228Ra chronology. Proc. Nat. Acad. Sci. 72:28292832.CrossRefGoogle ScholarPubMed