Here is an abstract for a paper of mine that was accepted for presentation at the 1999 International System Dynamics Conference in Wellington, New Zealand
The Mother of Mass Extinctions:
A Dynamic Examination of Biodiversity at the End of the Paleozoic Era

The greatest known loss of species since the beginning of life occurred 250 million years ago at the end of the Permian period, when an estimated 95% of all species became extinct. The great temporal distance of those events makes conclusive causal attributions much tougher than end-Cretaceous or Recent crises. Yet some inferences can be drawn from the evidence available. The end-Permian events seem to unfold over a much longer time than the end-Cretaceous events. Additional evidence can be gathered through a dynamic analysis of the explanations competing in the theoretical marketplace.

This paper examines the geography of Late Permian Earth, the factors responsible for its biodiversity potential, and how continental topology affected that diversity. Prominent among the proposed ultimate causes for the crisis are marine regression (a substantial drop in sea level), the Siberian traps (the largest known flood basalts) and bolide impact. The response of biodiversity to the observed changes in energy availability, climate, sea level, and continental distribution are simulated, individually and in combination, to mirror both terrestrial and extraterrestrial causal chains.

The author draws primarily from Douglas H. Erwin, The Great Paleozoic Crisis, 1993. This paper also builds on the research the author presented at ISDC '97 in a paper entitled "Sustaining Life: The Origin, Diversity, and Extinction of Species”. It differs from that work by focusing on the Permian/Triassic boundary, 250 million years ago, and by more closely examining through simulation the plausibility of competing scenarios of extinctions at that time.