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CPLC Seminar: "How networks drove the rapid evolution of early life: clues from the canonical genetic code"

Event Type
Center for the Physics of Living Cells
144 Loomis
Dec 7, 2012   2:00 pm  
Nigel Goldenfeld, Department of Physics, University of Illinois, Urbana
Shawn McCormick
Originating Calendar
Physics - Physics of Living Cells Seminar

Relics of early life, preceding even the last universal common ancestor of all life on Earth, are present in the structure of the modern day canonical genetic code --- the map between DNA sequence and amino acids that form proteins. The code is not random, as often assumed, but instead is now known to have certain error minimisation properties. How could such a code evolve, when it would seem that mutations to the code itself would cause the wrong proteins to be translated, thus killing the organism? Using digital life simulations, I show how a unique and optimal genetic code can emerge over evolutionary time, but only if horizontal gene transfer --- a network effect --- was a much stronger characteristic of early life than it is now. These results suggest a natural scenario in which evolution exhibits three distinct dynamical regimes, differentiated respectively by the way in which information flow, genetic novelty and complexity emerge.

Work done in collaboration with Carl Woese, Zan Luthey-Schulten, Kalin Vetsigian, Tom Butler, Damien Mathew

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