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The fossil record of evolution: Analysis of extinctionThere is increasing evidence that events in space have had direct effects on Earth history and on the history of life on Earth. Nowhere is this more evident than in mass extinction. The biosphere has undergone repeated devastation caused by relatively short-lived environmental stress, with species kill rates up to 80 and 95%. For five of the mass extinctions, geochemical or other evidence was reported suggesting large body impact as the cause of the environmental stress producing the extinctions. It was argued on statistical ground that the major extinction events are uniformly periodic in geological time. If it is true that large body impact is a principal cause of mass extinctions and if the periodicity is real, than a cosmic driving mechanism is inescapable. Paleontological data sets were developed which detail the ranges in geological time of about 4,000 families and 25,000 genera of fossil marine organisms. Analyses to date have concentrated on the most recent 250 million years. Associated with these studies are analyses of other aspects of Earth history which may have signatures indicative of extraterrestrial effects.
Document ID
19860017429
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Raup, D. M.
(Chicago Univ. Chicago, IL, United States)
Date Acquired
August 12, 2013
Publication Date
May 1, 1986
Publication Information
Publication: NASA, Washington Second Symposium on Chemical Evolution and the Origin and Evolution of Life
Subject Category
Space Biology
Accession Number
86N26901
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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