Dennis Bray – What Cells Can Do That Robots Can’t
“For all the walking, talking, housekeeping, car-building, child-entertaining, elderly-caring marvels of present-day robots; for all their amazing, superhuman ability to crunch numbers, play chess, store data, analyze sequences and display graphics they are still not like us. Superb specialists able to do one thing supremely well, robots and their computer brains lack the adaptability and the self-regenerating generalist abilities of living organisms. Above all, they lack the capacity of independent survival in the real world-something possessed by even the simplest organism. ” (Wetware. Y.U.P. 2009)
So what is missing? The answer, I argue, can be found in the discoveries of contemporary biology. Living cells are crammed full of molecules-especially proteins but also RNA molecules- that act as biochemical switches. Most are allosteric and modifiable- formally equivalent to transistors- and linked into extensive networks through diffusion limited binding events and biochemical reactions. Computational molecules perform tasks such as amplification, feedback inhibition, oscillation, coincidence detection, and memory storage. But although biological components act in ways that are comparable to those in electronic circuits, they are set apart by the huge number of different states they can adopt. Multiple biochemical processes create chemical modifications of protein molecules, further diversified by association with distinct structures at defined locations of a cell. The resulting combinatorial explosion of states endows living systems with an almost infinite capacity to store information regarding past and present conditions and a unique capacity to prepare for future events.
Dennis Bray provided a very detailed review of various cellular and protein processes. However, I get the impression that he has not seriously considered what can be done with artificial systems. So I am leaving partway through his talk and not staying for his debate.