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A New Mechanism of Mass Extinction - and 15 Minutes About a New Tree of Life

Presenter: Peter Ward, University of Washington
When: September 27, 2004 11AM PDT

Like ancient Gaul, this seminar will be composed of three parts. The first describes new carbon isotope, magnetostratigraphic, and paleontological findings from the Permian and Triassic sedimentary record found in the Karoo of South Africa. I will show that both the chemostratigraphic and paleontological record based on vertebrate fossils does not resemble the pattern observed at the Cretaceous/Paleogene boundaries, and thus at least on land the Permian mass extinction does not resemble our model of single strike, impact caused mass extinction. The second part of my talk will explore a new theoretical model of mass extinction based on the observations of falling oxygen levels at the end of the Permian. I will used McArthur-Wilson Island Biogeography models to show that some part of the Permian extinction on land can be blamed entirely on a reduction of habitat due to altitude by the end of the Permian, only sea level altitudes may have been habitable. Finally, I will finish my seminar with something totally different: I am proposing that a new taxonomic category superjacent to Domain is warranted. I call this category a Dominion, and place DNA life within the new Dominion Terroa. I define a second Dominion Ribosa, with two new domains, for RNA viruses and now-extinct RNA life. If life is found beyond the Earth that has no connection to the evolution on Earth, a further and higher category will have to be erected. I call these Arborea. Both the Dominions Terroa and Ribosa are included in an unnamed, Earth-life Arborea.

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