Browse Search Feedback Other Links Home Home The Talk.Origins Archive: Exploring the Creation/Evolution Controversy

Index to Creationist Claims,  edited by Mark Isaak,    Copyright © 2007
Previous Claim: CC251   |   List of Claims   |   Next Claim: CC301

Claim CC300:

Complex life forms appear suddenly in the Cambrian explosion, with no ancestral fossils.


Morris, Henry M. 1985. Scientific Creationism. Green Forest, AR: Master Books, pp. 80-81.
Watchtower Bible and Tract Society. 1985. Life--How Did It Get Here? Brooklyn, NY, pp. 60-62.


  1. The Cambrian explosion was the seemingly sudden appearance of a variety of complex animals about 540 million years ago (Mya), but it was not the origin of complex life. Evidence of multicellular life from about 590 and 560 Mya appears in the Doushantuo Formation in China (Chen et al. 2000, 2004), and diverse fossil forms occurred before 555 Mya (Martin et al. 2000). (The Cambrian began 543 Mya., and the Cambrian explosion is considered by many to start with the first trilobites, about 530 Mya.) Testate amoebae are known from about 750 Mya (Porter and Knoll 2000). There are tracelike fossils more than 1,200 Mya in the Stirling Range Formation of Australia (Rasmussen et al. 2002). Eukaryotes (which have relatively complex cells) may have arisen 2,700 Mya, according to fossil chemical evidence (Brocks et al. 1999). Stromatolites show evidence of microbial life 3,430 Mya (Allwood et al. 2006). Fossil microorganisms may have been found from 3,465 Mya (Schopf 1993). There is isotopic evidence of sulfur-reducing bacteria from 3,470 Mya (Shen et al. 2001) and possible evidence of microbial etching of volcanic glass from 3,480 Mya (Furnes et al. 2004).

  2. There are transitional fossils within the Cambrian explosion fossils. For example, there are lobopods (basically worms with legs) which are intermediate between arthropods and worms (Conway Morris 1998).

  3. Only some phyla appear in the Cambrian explosion. In particular, all plants postdate the Cambrian, and flowering plants, by far the dominant form of land life today, only appeared about 140 Mya (Brown 1999).

    Even among animals, not all types appear in the Cambrian. Cnidarians, sponges, and probably other phyla appeared before the Cambrian. Molecular evidence shows that at least six animal phyla are Precambrian (Wang et al. 1999). Bryozoans appear first in the Ordovician. Many other soft-bodied phyla do not appear in the fossil record until much later. Although many new animal forms appeared during the Cambrian, not all did. According to one reference (Collins 1994), eleven of thirty-two metazoan phyla appear during the Cambrian, one appears Precambrian, eight after the Cambrian, and twelve have no fossil record.

    And that just considers phyla. Almost none of the animal groups that people think of as groups, such as mammals, reptiles, birds, insects, and spiders, appeared in the Cambrian. The fish that appeared in the Cambrian was unlike any fish alive today.

  4. The length of the Cambrian explosion is ambiguous and uncertain, but five to ten million years is a reasonable estimate; some say the explosion spans forty million years or more, starting about 553 million years ago. Even the shortest estimate of five million years is hardly sudden.

  5. There are some plausible explanations for why diversification may have been relatively sudden:

  6. Cambrian life was still unlike almost everything alive today. Although several phyla appear to have diverged in the Early Cambrian or before, most of the phylum-level body plans appear in the fossil record much later (Budd and Jensen 2000). Using number of cell types as a measure of complexity, we see that complexity has been increasing more or less constantly since the beginning of the Cambrian (Valentine et al. 1994).

  7. Major radiations of life forms have occurred at other times, too. One of the most extensive diversifications of life occurred in the Ordovician, for example (Miller 1997).


  1. Allwood, A. C. et al. 2006. Stromatolite reef from the Early Archaean era of Australia. Nature 441: 714-718. See also Awramik, Stanley M. 2006. Respect for stromatolites. Nature 441: 700-701.
  2. Brocks, J. J., G. A. Logan, R. Buick and R. E. Summons, 1999. Archean molecular fossils and the early rise of eukaryotes. Science 285: 1033-1036. See also Knoll, A. H., 1999. A new molecular window on early life. Science 285: 1025-1026.
  3. Brown, Kathryn S., 1999. Deep Green rewrites evolutionary history of plants. Science 285: 990-991.
  4. Budd, Graham E. and Sören Jensen. 2000. A critical reappraisal of the fossil record of the bilaterian phyla. Biological Reviews 75: 253-295.
  5. Canfield, D. E. and A. Teske, 1996. Late Proterozoic rise in atmospheric oxygen concentration inferred from phylogenetic and sulphur-isotope studies. Nature 382: 127-132. See also: Knoll, A. H., 1996. Breathing room for early animals. Nature 382: 111-112.
  6. Carroll, Robert L., 1997. Patterns and Processes of Vertebrate Evolution. Cambridge University Press.
  7. Chen, J.-Y. et al., 2000. Precambrian animal diversity: Putative phosphatized embryos from the Doushantuo Formation of China. Proceedings of the National Academy of Science USA 97(9): 4457-4462.
  8. Chen, J.-Y. et al., 2004. Small bilaterian fossils from 40 to 55 million years before the Cambrian. Science 305: 218-222, . See also Stokstad, E., 2004. Controversial fossil could shed light on early animals' blueprint. Science 304: 1425.
  9. Collins, Allen G., 1994. Metazoa: Fossil record.
  10. Conway Morris, Simon, 1998. The Crucible of Creation, Oxford.
  11. Cook, P. J. and J. H. Shergold (eds.), 1986. Phosphate Deposits of the World, Volume 1. Proterozoic and Cambrian Phosphorites. Cambridge University Press.
  12. Furnes, H., N. R. Banerjee, K. Muehlenbachs, H. Staudigel and M. de Wit, 2004. Early life recorded in Archean pillow lavas. Science 304: 578-581.
  13. Hoffman, Paul F. et al., 1998. A Neoproterozoic snowball earth. Science 281: 1342-1346. See also: Kerr, Richard A., 1998. Did an ancient deep freeze nearly doom life? Science 281: 1259,1261.
  14. Kerr, Richard A., 2000. An appealing snowball earth that's still hard to swallow. Science 287: 1734-1736.
  15. Logan, G. A., J. M. Hayes, G. B. Hieshima and R. E. Summons, 1995. Terminal Proterozoic reorganization of biogeochemical cycles. Nature 376: 53-56. See also Walter, M., 1995. Faecal pellets in world events. Nature 376: 16-17.
  16. Lipps, J. H. and P. W. Signor (eds.), 1992. Origin and Early Evolution of the Metazoa. New York: Plenum Press.
  17. Martin, M. W. et al., 2000. Age of Neoproterozoic bilatarian body and trace fossils, White Sea, Russia: Implications for metazoan evolution. Science 288: 841-845. See also Kerr, Richard A., 2000. Stretching the reign of early animals. Science 288: 789.
  18. Miller, Arnold I., 1997. Dissecting global diversity patterns: Examples from the Ordovician radiation. Annual Review of Ecology and Systematics 28: 85-104.
  19. Porter, Susannah M. and Andrew H. Knoll, 2000. Testate amoebae in the Neoproterozoic Era: evidence from vase-shaped microfossils in the Chuar Group, Grand Canyon. Paleobiology 26(3): 360-385.
  20. Rasmussen, B., S. Bengtson, I. R. Fletcher and N. J. McNaughton, 2002. Discoidal impressions and trace-like fossils more than 1200 million years old. Science 296: 1112-1115.
  21. Schopf, J. W., 1993. Microfossils of the Early Archean Apex Chert: New evidence of the antiquity of life. Science 260: 640-646.
  22. Shen, Y., R. Buick and D. E. Canfield, 2001. Isotopic evidence for microbial sulphate reduction in the early Archaean era. Nature 410: 77-81.
  23. Thomas, A. L. R., 1997. The breath of life -- did increased oxygen levels trigger the Cambrian Explosion? Trends in Ecology and Evolution 12: 44-45.
  24. Valentine, James W., Allen G. Collins and C. Porter Meyer, 1994. Morphological complexity increase in metazoans. Paleobiology 20(2): 131-142.
  25. Wang, D. Y.-C., S. Kumar and S. B. Hedges, 1999. Divergence time estimates for the early history of animal phyla and the origin of plants, animals and fungi. Proceedings of the Royal Society of London, Series B, Biological Sciences 266: 163-71.

Further Reading:

Conway Morris, Simon. 1998. The Crucible of Creation. Oxford.

Conway Morris, Simon. 2000. The Cambrian "explosion": Slow-fuse or megatonnage? Proceedings of the National Academy of Science USA 97(9): 4426-4429. (technical)

Schopf, J. William. 2000. Solution to Darwin's dilemma: Discovery of the missing Precambrian record of life. Proceedings of the National Academy of Science USA 97(13): 6947-6953.
Previous Claim: CC251   |   List of Claims   |   Next Claim: CC301

created 2001-3-31, modified 2006-12-5