On the stability of life

60sec_082.jpgThe University of Pennsylvania hosts a 60 second lecture series, in which faculty provide a perspective on their scholarship in just one minute. The constrained format seems to produce lectures that are more like performance, and language that is more like poetry. It’s an unusual opportunity to hear how scholars address some of the broadest philosophical questions in the simplest terms possible… in some cases, revealing some elegant thinking along the way. The lectures—all available for viewing online in the archives—have included topics like “John F. Kennedy’s Sex Life” and “Why is Mathematics Useful?

Today’s lecture, “On the Stability of Life,” was delivered by Joshua Plotkin. He links thermodynamics and the evolutionary process in describing the existence of life:

Ask yourselves: Is life possible? It doesn’t seem so, at least thermodynamically. After all, your skin cells are replaced every 6 weeks. All the atoms in your body are recycled each year, replaced by other atoms that were created billions of years ago, light-years away. And so in what sense are you the same person from year to year? Certainly in no physical sense. But you think you are alive, and stable enough to call yourself an individual. In what sense, then, are you stable? In an evolutionary sense. Your genetic information, though thermodynamically fragile, is dynamically repaired and transmitted with fidelity. Not perfect fidelity, thank goodness. Imperfections do arise from time to time. Without these mutations, evolution could not proceed. And so, the same entropic forces that threaten to destabilize life also allow life to evolve. Think about that, for a minute.

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