kw: book reviews, nonfiction, synthetic life
The recent book by Ed Regis, What is Life? Investigating the Nature of Life in the Age of Synthetic Biology, may be considered the third of a series. In 1945, Edwin Schrodinger, of the "Schrodinger Equation" that can (with strenuous labor) calculate the properties of any atom's electron cloud, and whose eponymous Cat defines the dilemma of quantum phenomena in a macroscopic world, wrote What is life? The Physical Aspect of the Living Cell, in which he did not answer the title question, but explored life phenomena from a strictly chemical and physical aspect. He predicted crucial aspects of the genetic code a decade or two in advance of their discovery. Then in 1995 Lynn Margulis brought certain of the same themes more up to date in What is Life?, shortly thereafter revised and reprinted with her son Dorian Sagan as co-author. As Ed Regis reports, Margulis and Sagan answered the question in so many ways that it is not answered at all.
Author Regis begins his book with a look at the formation of a four-way consortium in 2002, with the aim of specifically creating a living cell not based on previously living matter. To date, the effort has not succeeded, but as Edison would have said, they are learning a great number of things that don't work...and a few that offer tantalizing clues to what might work. So much so, that the government is now interested, as evidenced by the Los Alamos Protocells web site and its link to protocell.org, a jumping-off place to a handful of major efforts in the Synthetic Life arena.
Regis does home in on an answer, a minimalist definition that life is "embodied metabolism". A few caveats are needed, such as a measure of autonomy and of self-repair, for example: An automobile consumes fuel and moves about, but does not direct its own motions nor maintain itself, while a portion of the metabolism of living cells goes to structural regeneration and growth. And "embodied" is needed to distinguish living matter from open flames.
More generally speaking, living things not only metabolize, they also reproduce and evolve. Not every individual will do so, but all can do so. And, specifically for all life that we know, all life processes are directed by coded instructions. DNA carries the instructions, while RNA plus proteins carry them out. Synthetic cells could be based on DNA, RNA and proteins, or it could instead use different chemistry, perhaps not even based on carbon. But whenever a wholly synthetic "embodied metabolism" gets cranked up, performing as cells perform, I suppose we'll have to dub it "living".
This is quite a step beyond our fearsome archetype, the Frankenstein monster. That creature was supposedly produced by re-animating a sewn-together collection of bits of corpses. Certain partial successes in the synthetic life area have been analogous to this. But the goal is to create living cells from chemicals, not from various bits taken from other cells.
The rub comes if the creators of synthetic life endow it with the ability to reproduce; the ability to evolve will come along as baggage immediately. At that point, no matter what precautions they may take, SynLife (not my term: Google yields 3,770 hits) will most certainly escape into "our" environment, evolve so as to take advantage of it, and then we'll really learn what it is like to live with invasive alien species! Sparrows, multiflora roses, and zebra mussels will probably pale by comparison.
I suggest that, really early on, SynLife cells be presented as a challenge to a large variety of prokaryotes, so they'll have a chance to develop resistance mechanisms and chemicals that we can later exploit when we need AntiSynBiotics!!
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