Curator Emeritus
Negaunee Integrative Research Center
I am a paleontologist and marine ecologist who studies invertebrate animals, that is, most of the different kinds of animals that have ever lived on Earth. I see my research as comparative:
- describing and explaining the history of life that actually can be observed as patterns in the fossil record, such as the changing forms of skeletons through time, or long-term trends in biodiversity,
- jointly studying processes that can only be inferred from fossils, such as the mechanisms of actual biological interactions, or the evolution of complexity that occurs at the different levels of organism and community, and
- comparing these with patterns and processes that can be seen in the living world, such as the development and life cycles of organisms, and the ecological processes of communities.
Representative Articles:
Nyhart, L. K. and S. Lidgard. 2011. Individuals at the center of biology: Rudolf Leuckart’s Polymorphismus der Individuenand the ongoing narrative of parts and wholes. With an annotated translation. Journal of the History of Biology. Online first: http://www.springerlink.com/content/b1n5h32v51582385/
Lidgard, S., P. J. Wagner & M. Kosnick. 2009. The search for evidence of mass extinction. Natural History118(7): 26-32.
Dick, M. H., S. Lidgard, D. P. Gordon & S. F. Mawatari 2009. The origin of ascophoran bryozoans was historically contingent but likely. Proceedings of the Royal Society B-Biological Sciences276(1670):3141-3148.
Ostrovsky, A. N., D. P. Gordon & S. Lidgard. 2009. Independent evolution of matrot...
Research Sketch
I first consider the broad context and importance of a problem, then try to find fossil and modern systems that are most amenable to empirical analyses, that provide complementary perspectives, and that offer sources of reliable data. This approach sometimes takes me in directions apart from the colonial animals I know and love best, cheilostome bryozoans. My past research projects have analyzed the evolution of different ways of growing in bryozoans; species competition between different bryozoan groups and how that affected their diversity and distribution; the diversification of flowering plants in the Cretaceous Period; the different historical stories told by fossil taxonomic richness and fossil abundance - how many species versus how many individuals; and how marine community complexity has increased over time.
Bryozoans remain at the center of my research vision, together with understanding the evolution and ecology of modular organisms in general. A biological module is part of an organism that exhibits higher within-part integration of processes – development, function, structure and so on – and lower integration with other relatively autonomous parts. In modular organisms such as higher plants and colonial animals like corals and bryozoans, the fertilized egg develops into a semi-discrete body that then makes more bodies like itself, but does so without sex.
This process and the consequent result of another level of variation within the organization of a genetic individual opens up a fascinating realm of questions: how do alternate forms (polymorphisms) evolve, yet have the same genotype?; what is the nature of individuality ...
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