Richard Wolfenden, PhD (UNC-Chapel Hill)

"Impact of temperature on biochemical evolution and the tempo of spontaneous mutation"

When Jan 20, 2015
from 11:00 AM to 12:00 PM
Where Bioinformatics 1131
Contact Name
Attendees Open to the public
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"Impact of temperature on biochemical evolution and the tempo of spontaneous mutation"

Wolfenden

Richard Wolfenden, PhD

Alumni Distinguished Professor
Department of Biophysics and Biochemistry
University of North Carolina, Chapel Hill, NC

Abstract: Echoing a powerful argument advanced by Lord Kelvin, the founder of thermodynamics, modern “creation scientists” claim that not enough time had elapsed for life on Earth to have reached its present level of complexity. However: (1) We have uncovered the startling extent to which slow reactions are accelerated by elevated temperatures. On a warm earth, this would have collapsed–by many orders of magnitude–the time that would have been required for chemical events before the advent of enzymes. (2) A primitive enzyme, if it enhanced the rate of a reaction by lowering its enthalpy of activation, would have produced a rate enhancement that increased–automatically–as the environment cooled. We find that PLP and metal ions exhibit that behavior, as do most present-day enzymes. (3) That scenario for enzyme evolution does not take into account improvements arising by natural selection. We find that the chemical events in spontaneous mutation are extremely sensitive to temperature, supplying an independent mechanism for accelerating evolution during Earth’s early history.

Wolfenden Lab

Host: Leslie Parise, PhD