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The Ohio State University
College of Mathematical & Physical Sciences
Department of Astronomy Colloquium Series 2006/7
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Thursday, March 1, 3:30 p.m.
2015 McPherson Laboratory
Spectral Analysis of Biodiversity Cycles
and Galactic Dynamics
Adrian Melott
University of Kansas
We have analyzed the power spectral and phase relationships of fluctuations
in biodiversity, species origination, rate of extinction, and motion of the
solar system normal to the galactic plane over the last 500 MY. The period
of the dominant spectral component is the same 62 MY for all these except
extinction. This is the same as the rate of gene duplication events,
suggesting some sort of causal relationship. The spectra suggest that the
biodiversity cycle is more closely related to origination rates than
extinction rates. Biodiversity and solar motion are offset in phase, with
gene duplication and origination lagging and leading biodiversity by
approximately two radians. A picture emerges consistent with a rising rate
of mutation and stress on the biosphere as the solar system moves to galactic
north, possibly exposed to higher cosmic rays from a galactic bow shock,
and species origination as it returns to the magnetic shielding of the
galactic disk.
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Modified 2007 Feb 9 [bsr]