By examining the records of climate changes over the past 600 million years, what caused the changes, and what effects they had on ancient organisms, these scientists are discovering what implications this information has for understanding Earth's history.
The most important general themes of the papers in this session are: (1) the adoption of a systems approach to the understanding of Earth's history (major events being caused by multiple, independent factors) and (2) the significance of 'feedback mechanisms.'
Some of the highlights are as follows:
Session co-chair Norman MacLeod will begin by taking a look at the identifying controls on Phanerozoic extinction and diversification patterns. (MacLeod is the Associate Keeper in the Department of Palaeontology at The Natural History Museum in London.) Patterns of biodiversification and extinction over the last 250 million years show evidence of having been controlled by multiple factors, especially the interplay between tectonic processes (e.g., volcanism, sea-level change), and the evolutionary history of primary producer lineages (e.g., phytoplankton and land plants).
Doug Erwin, from the Department of Paleobiology at the Smithsonian Institution, will explain how the biodiversity increase that characterizes the biotic recovery from a mass extinction event is structured by ecological factors to a larger extent than previously thought.
Paul Wignall, Earth Sciences Department at the University of Leeds, has discovered that the relationship between mass extinction events and large volcanic eruptions is complex and likely involves climate forcing factors other than the eruption itself, including the pr
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Contact: Ann Cairns
acairns@geosociety.org
303-447-2020 ext1156
Geological Society of America
13-Jun-2001