A Macroevolutionary Study on Tetrapod Diversity from the Devonian to the Present
Changing geography, climate and mass extinctions continually reshaped the environment throughout the Phanerozoic. And as tetrapods expanded on land, their interactions with each other and other life grew increasingly complex. These biotic and abiotic factors caused large shifts in the variety and abundance of major groups.
This changing diversity can be measured in many different ways. Usually taxa are tabulated at geological intervals on a global scale, but alternative views may be considered. Benton (1998) showed diversity as a function of global changes in origination and extinction rates over time, Bambach (1977) examined alpha (community level) diversity patterns of fossil marine communities, and Sepkoski (1988) studied how alpha, beta (between community) and gamma (between region) diversity contributed to global marine diversity in the Paleozoic.
This study examines tetrapod diversity in numerous communities from the Devonian to the present, defining worldwide alpha diversity patterns. By modeling these patterns, comparisons can be made to global tetrapod diversity as well as to the diversity of other taxa such as terrestrial plants and invertebrates. Diversity links with biogeography, climate and major events such as mass extinctions are also be explored.
Alpha Diversity Database (ADD)
My research and that of the MSc students I am cosupervising is being conducted through an online Relational Database Management System (RDMS). This system is specifically designed to collect information about the diversity of communities, hence the name, Alpha Diversity Database. The database is not yet available for online viewing but data on Palaeozoic vertebrate communities will be available soon.
Palaeozoic Data
The early focus of my research has been the diversification of Palaeozoic vertebrate communities of a few piscivore species in the Devonian to diverse Permian communities with complex food webs and a variety of body sizes. I presented the results of this research at the International Palaeontological Congress (IPC) in Beijing and at the Society of Vertebrate Paleontology Annual Meeting (SVP)in Ottawa.
References
Bambach, R.K. 1977. Species richness in marine benthic habitats through the Phanerozoic. Paleobiology 3:152-167.
Benton, M.J. 1998. The quality of the fossil record of vertebrates. The Adequacy of the Fossil Record. S.K. Donovan and C.R.C. Paul. New York, Wiley: 269-303.
Sepkoski, J.J., Jr. 1988. Alpha, beta, or gamma: where does all the diversity go? Paleobiology 14:221-234.
