Hi Bernardo, you might find the work of paleontologist Jack Sepkoski very interesting. This in an excerpt from a blog I wrote a few years ago that might interest you:
Let’s consider the work of Jack Sepkoski, a paleontologist best known for his global compendia of marine animal families and genera. Sepkoski (1981,1984, 1990) used factor analysis of marine family diversity to produce a model of Phanerozoic diversity patterns involving three “Evolutionary Faunas” (EF’s) with distinct periods of diversification and taxonomic dominance (Figure 1). Successive faunas demonstrate declining origination rates and increased levels if equilibrium diversity in comparison to their predecessors. Based on this model, Sepkoski proposed that the Late Cambrian plateau of taxonomic diversity represented the point where the equilibrium between extinction rates and diversification rates had been achieved in regards to the Cambrian EF. The Paleozoic EF initially exhibited a much slower diversification rate than the Cambrian explosion, but was able to attain much higher levels of diversity than the Cambrian fauna before being superceded by the Modern EF. |
Based on his mathematical modeling of global diversity, Sepkoski (1979, 1984) viewed the Ordovician Radiation as the logical result of intrinsic factors, a natural consequence of diversity-dependent interactions between the established Cambrian EF and the newly diversifying Paleozoic EF. In light of more recent works that highlight external influences on diversity (i.e. Miller, 1997a, 1997b; Miller and Mao, 1995), the importance placed on such intrinsic factors has been diminished. In spite of this, Sepkoski’s model endures due to its success in modeling Early Paleozoic patterns of diversification. Nearly all of the phyla and most of the clades that radiated during the Ordovician originated during the Cambrian. Even without a definitive link, this suggests that the Ordovician Radiation was influenced on a very fundamental level by the Cambrian explosion (Erwin et al, 1987; Miller, 2004).
Erwin, D.H., Valentine, J.W. and Sepkoski, J.J. Jr., 1987. A comparative study of diversification events: The Early Paleozoic versus the Mesozoic. Evolution 41:1177-1186.
Miller, A.I. 1997a. Dissecting global diversity patterns: Examples from the Ordovician Radiation. Annual Review of Ecology and Systematics 28:85-104.
Miller, A.I. 1997b. Comparative diversification dynamics among paleocontinents during the Ordovician Radiation. Geobios M.S. 30(S1):397-406.
Miller A.I., 2004. The Ordovician Radiation: Toward a New Global Synthesis. In B.D. Webby, F. Paris, M.L. Droser, and I.G Percival (eds), The Great Ordovician Biodiversification Event, pp. 381-388. Columbia University Press, New York.
Miller, A.I. and Mao, S.G., 1995. Association of orogenic activity with the Ordovician radiation of marine life. Geology 23:305-308.
Sepkoski, J.J. Jr., 1979. A kinetic model of Phanerozoic taxonomic diversity, II: Early Phanerozoic families and multiple equilibria. Paleobiology 5:222-252.
Sepkoski, J.J. Jr., 1981. A factor analytic description of the Phanerozoic marine fossil record. Paleobiology 7:36-53.
Sepkoski, J.J. Jr., 1984. A kinetic model of Phanerozoic taxonomic diversity, III: Post-Paleozoic families and mass extinctions. Paleobiology 10:246-267.
Sepkoski, J.J. Jr., 1990. Evolutionary faunas. In Briggs, D.E.G. and Crowther, P.R. (eds) Paleobiology: A synthesis, pp. 37-41. Blackwell Scientific Publications, Oxford.