A New History of Life (56 page)

  
3.
   Jim Gehling is one of the giants of Australian science, but more, he has collaborated with a veritable who’s who of international science in his career-long work on the Ediacarans. The new exhibit he organized is worth a trip to Adelaide alone. See J. G. Gehling et al., in D. E. G. Briggs, ed.,
Evolving Form and Function: Fossils and Development
(Yale Peabody Museum, 2005), 45–56; J. G. Gehling et al., “The First Named Ediacaran Body Fossil, Aspidella terranovica,”
Palaeontology
43, no. 3 (2000): 429; J. G. Gehling, “Microbial Mats in Terminal Proterozoic Siliciclastics; Ediacaran Death Masks,”
Palaios
14, no. 1(1999): 40–57.

  
4.
   P. F. Hoffman et al., “A Neoproterozoic Snowball Earth,”
Science
281, no. 5381 (1998): 1342–46; F. A. Macdonald et al., “Calibrating the Cryogenian,”
Science
, 327, no. 5970 (2010): 1241–43.

  
5.
   F. A. Macdonald et al., “Calibrating the Cryogenian,”
Science
327, no. 5970 (2010): 1241–43.

  
6.
   B. Shen et al., “The Avalon Explosion: Evolution of Ediacara Morphospace,”
Science
319 no. 5859 (2008): 81–84; G. M. Narbonne, “The Ediacara Biota: A Terminal Neoproterozoic Experiment in the Evolution of Life,”
Geological Society of America
8, no. 2 (1998): 1–6; S. Xiao and M. Laflamme, “On the Eve of Animal Radiation: Phylogeny, Ecology and Evolution of the Ediacara Biota,”
Trends in Ecology and Evolution
24, no. 1 (2009): 31–40.

  
7.
   R. Sprigg, “On the 1946 Discovery of the Precambrian Ediacaran Fossil Fauna in South Australia,”
Earth Sciences History
7 (1988): 46–51.

  
8.
   S. Turner and P. Vickers-Rich, “Sprigg, Martin F. Glaessner, Mary Wade and the Ediacaran Fauna,” Abstract for IGCP 493 conference, Prato Workshop, Monash University Centre, August 30–31, 2004.

  
9.
   A. Seilacher, “Vendobionta and Psammocorallia: Lost Constructions of Precambrian Evolution,”
Journal of the Geological Society, London
149, no. 4 (1992): 607–13; A. Seilacher et al., “Ediacaran Biota: The Dawn of Animal Life in the Shadow of Giant Protists,”
Paleontological Research
7, no. 1 (2003): 43–54. Dolph Seilacher was one of a kind. He and his wife, Edith, were world travelers. He was a champion of science, and one of the warmest scientists we have known. For a full list of his work, see Derek Briggs, ed.,
Evolving Form and Function: A Special Publication of the Peabody Museum of Natural History
(New Haven, CT: Yale University 2005).

10.
   Martin Glaesner, a longtime faculty member at the University of Adelaide, lives on in that institution with his well-stocked Glaesner Room in Mawson Hall, where many of the fossil he collected and his copious notes can be found.

11.
   South Australian Museum, Ediacaran fossils.
www.samuseum.sa.gov.au/explore/museum-galleries/ediacaran-fossils
.

12.
   B. Waggoner, “Interpreting the Earliest Metazoan Fossils: What Can We Learn?”
Integrative and Comparative Biology
38, no. 6 (1998): 975–82; D. E. Canfield et al., “Late-Neoproterozoic Deep-Ocean Oxygenation and the Rise of Animal Life,”
Science
315, no. 5808 (2007): 92–95; B. Shen et al., “The Avalon Explosion: Evolution of Ediacara Morphospace,”
Science
319, no. 5859 (2008): 81–84.

13.
   B. MacGabhann, “There Is No Such Thing as the ‘Ediacaran Biota,’”
Geoscience Frontiers
5, no. 1 (2014): 53–62.

14.
   N. J. Butterfield, “
Bangiomorpha pubescens
n. gen., n. sp.: Implications for the Evolution of Sex, Multicellularity, and the Mesoproterozoic-Neoproterozoic Radiation of Eukaryotes,”
Paleobiology
26, no. 3 (2000): 386–404.

15.
   M. Brasier et al., “Ediacaran Sponge Spicule Clusters from Mongolia and the Origins of the Cambrian Fauna,”
Geology
25 (1997): 303–06.

16.
   J. Y. Chen et al., “Small Bilaterian Fossils from 40 to 55 Million Years before the Cambrian,”
Science
305, no. 5681 (2004): 218–22; A. H. Knoll et al. “Eukaryotic Organisms in Proterozoic Oceans,”
Philosophical Transactions of the Royal Society
361, no. 1470 (2006): 1023–38; B. Waggoner, “Interpreting the Earliest Metazoan Fossils: What Can We Learn?”
Integrative and Comparative Biology
38, no. 6 (1998): 975–82.

17.
   A. Seilacher and F. Pflüger, “From Biomats to Benthic Agriculture: A Biohistoric Revolution,” in W. E. Krumbein et al., eds.,
Biostabilization of Sediments
. (Bibliotheks- und Informationssystem der Carl von Ossietzky Universität Odenburg, 1994), 97–105; A. Ivantsov, “Feeding Traces of the Ediacaran Animals,” Abstract, 33rd International Geological Congress August 6–14, 2008, Oslo, Norway; S. Dornbos et al., “Evidence for Seafloor Microbial Mats and Associated Metazoan Lifestyles in Lower Cambrian Phosphorites of Southwest China,”
Lethaia
37, no. 2 (2004): 127–37.

18.
   The data from Svalbard are from A. C. Maloof et al., “Combined Paleomagnetic, Isotopic, and Stratigraphic Evidence for True Polar Wander from the
Neoproterozoic Akademikerbreen Group, Svalbard, Norway,”
Geological Society of America Bulletin
, 118, nos. 9–10 (2006): 1099–124; the matching data from Central Australia are from N. L. Swanson-Hysell et al., “Constraints on Neoproterozoic Paleogeography and Paleozoic Orogenesis from Paleomagnetic Records of the Bitter Springs Formation, Amadeus Basin, Central Australia,”
American Journal of Science
312, no. 8 (2012): 817–84.

19.
   R. N. Mitchell, “True Polar Wander and Supercontinent Cycles: Implications for Lithospheric Elasticity and the Triaxial Earth,”
American Journal of Science
314, no. 5 (2014): 966–78.

20.
   J. Kirschvink, R. Ripperdan, D. Evans, “Evidence for Large Scale Reorganization of Early Cambrian Continental Masses by Inertial Interchange True Polar Wander,”
Science
277, no. 5325 (1997): 541–45.

  
1.
   Sadly, this great book is no longer required of college students. At the University of Washington we have tried to reverse that, requiring students enrolled in the course A New History of Life to read C. Darwin
On the Origin of Species by Natural Selection
(London: 1859).

  
2.
   A wonderful guide to the Cambrian as well as Darwin and the Burgess Shale is in the indispensable book by S. J. Gould,
Wonderful Life: The Burgess Shale and the Nature of History
(New York: W. W. Norton & Company, 1989). Steve, a friend to us both, was the greatest lecturer either of us has ever heard. His was a voice that had to be heard in person. His power as a lecturer came from his enormous intellect and mastery of both the science of evolution and Darwin, the English master. How that voice of reason, eloquence, and science is missed. If Huxley was Darwin’s bulldog, Gould was his pit bull.

  
3.
   K. J. McNamara, “Dating the Origin of Animals,”
Science
274, no. 5295 (1996): 1993–97.

  
4.
   A. H. Knoll and S. B. Carroll, “Early Animal Evolution: Emerging Views from Comparative Biology and Geology,”
Science
284, no. 5423 (1999): 2129–371.

  
5.
   K. J. Peterson and N. J. Butterfield, “Origin of the Eumetazoa: Testing Ecological Predictions of Molecular Clocks Against the Proterozoic Fossil Record,”
Proceedings of the National Academy of Sciences
102, no. 27 (2005): 9547–52.

  
6.
   M. A. Fedonkin et al.,
The Rise of Animals: Evolution and Diversification of the Kingdom Animalia
(Baltimore: Johns Hopkins University Press, 2007), 213–16.

  
7.
   It is hard to argue with the view that the Cambrian explosion is one of the—if not the—preeminent events in paleontology. However, those studying how life first arose view animals as latecomers of not much importance: that getting to life was the hard part, and animals were then foreordained once life arose. We remain split on this. There are many good papers of recent vintage dealing with this relative importance. Among them are: G. E Budd and J. Jensen, “A Critical Reappraisal of the Fossil Record of the Bilaterian Phyla,”
Biological Reviews
75, no. 2 (2000): 253–95; and S. J. Gould,
Wonderful Life
.

  
8.
   Oxygen levels in the Cambrian remain controversial. We continue to trust Bob Berner’s work using his GEOCARBSULF models: R. A. Berner, “GEOCARBSULF: A Combined Model for Phanerozoic Atmospheric Oxygen and Carbon Dioxide,”
Geochimica et Cosmochimica Acta
70 (2006): 5653–64.

  
9.
   N. J. Butterfield, “Exceptional Fossil Preservation and the Cambrian Explosion,”
Integrative and Comparative Biology
43, no. 1 (2003): 166–77; S. C. Morris, “The Burgess Shale (Middle Cambrian) Fauna,”
Annual Review of Ecology and Systematics
10, no. 1 (1979): 327–49.

10.
   D. Briggs et al.,
The Fossils of the Burgess Shale
(Washington, D.C.: Smithsonian Institution Press, 1994).

11.
   H. B. Whittington, Geological Survey of Canada,
The Burgess Shale
(New Haven: Yale University Press, 1985), 306–308.

12.
   J. W. Valentine,
On the Origin of Phyla
(Chicago: University of Chicago Press, 2004). See also J. W. Valentine and D. Erwin,
The Cambrian Explosion: The Construction of Animal Biodiversity
(Roberts and Co. Publishing, 2013). 413; J. W. Valentine, “Why No New Phyla after the Cambrian? Genome and Ecospace Hypotheses Revisited,” abstract,
Palaios
10, no. 2 (1995): 190–91. See also S. Bengtson, “Origins and Early Evolution of Predation” (free full text), in M. Kowalewski and P. H. Kelley,
The Fossil Record of Predation. The Paleontological Society Papers 8
(Paleontological Society, 2002): 289–317.

13.
   P. Ward,
Out of Thin Air
(Joseph Henry Press, 2006).

14.
   S. Carroll,
Endless Forms Most Beautiful: The New Science of Evo Devo and the Making of the Animal Kingdom
(New York: W. W. Norton & Company, 2004).

15.
   H. X. Guang et al.,
The Cambrian Fossils of Chengjiang, China: The Flowering of Early Animal Life
. (Oxford: Blackwell Publishing, 2004).

16.
   This nasty fight between two very literate writers would have ended up on the dueling ground, with one or both dead, were it still the 1800s. Gould was nothing but appreciative and polite to Simon. The reverse did not hold.

17.
   M. Brasier et al., “Decision on the Precambrian-Cambrian Boundary Stratotype,”
Episodes
17, nos. 1–2 (1994): 95–100.

18.
   W. Compston et al., “Zircon U-Pb Ages for the Early Cambrian Time Scale,”
Journal of the Geological Society of London
149 (1992): 171–84.

19.
   A. C. Maloof et al., “Constraints on Early Cambrian Carbon Cycling from the Duration of the Nemakit-Daldynian-Tommotian Boundary Delta C-13 Shift, Morocco,”
Geology
38, no. 7 (2010): 623–26.

20.
   M. Magaritz et al., “Carbon-Isotope Events Across the Precambrian-Cambrian Boundary on the Siberian Platform,”
Nature
320 (1986): 258–59.

  
1.
   There is no better source to refer to about ancient reefs than our friend George Stanley of the University of Montana. A good place to start is his magnificent book: G. Stanley,
The History and Sedimentology of Ancient Reef Systems
(Springer Publishing, 2001). Another good source is E. Flügel in W. Kiessling,
E. Flügel, and J. Golonka, eds.,
Phanerozoic Reef Patterns
72 (SEPM Special Publications, 2002), 391–463.

  
2.
   Archaeocyathids are one of the most curious of all fossils. In the twentieth century they were thought to belong to no known phylum. Now they are put into the sponges. But they have a curious structure of a “cone in a cone”—as if one hollow ice-cream cone is stacked into a second. They are prominent in being the very first reef-forming organisms that we know of, as they formed three-dimensional wave-resistant structures built by organisms—our definition of a reef. F. Debrenne and J. Vacelet, “Archaeocyatha: Is the Sponge Model Consistent with Their Structural Organization?”
Palaeontographica Americana
54 (1984): 358–69.

  
3.
   T. Servais et al., “The Ordovician Biodiversification: Revolution in the Oceanic Trophic Chain,”
Lethaia
41, no.2 (2008): 99.

  
4.
   P. Ward,
Out of Thin Air: Dinosaurs, Birds, and Earth’s Ancient Atmosphere
(Washington, D.C.: Joseph Henry Press, 2006).

  
5.
   P. Ward,
Out of Thin Air
. Also see a magnificent summary by our colleague and coauthor on extinction, C. R. Marshall, “Explaining the Cambrian ‘Explosion’ of Animals,”
Annual Review of Earth and Planetary Sciences
34 (2006): 355–84.

  
6.
   J. Valentine, “How Many Marine Invertebrate Fossils?”
Journal of Paleontology
44 (1970): 410–15; N. Newell, “Adequacy of the Fossil Record,”
Journal of Paleontology
33 (1959): 488–99.

  
7.
   D. M. Raup, “Taxonomic Diversity During the Phanerozoic,”
Science
177 (1972): 1065–71; D. Raup, “Species Diversity in the Phanerozoic: An Interpretation,”
Paleobiology
2 (1976): 289–97.