Entropy and Gravity, a Useful Analogy

Entropy crops up here and there in debates over the feasibility of developing working anti-aging medicine. For example, see Preston Estep's comments, which sum up the "entropy is bad for the prospects of healthy life extension" position:

In plain English, the loss of order and information essential for biological function. The general concept of biological entropy encompasses several dynamic phenomena ... It is difficult to imagine how the information-rich order that is established during embryogenesis and development can be restored or replicated.

This sort of argument is considered to be an unhelpful, wrong or irrelevant by - so far as I can see - most scientists in the field. Steve Harris put forward a very useful analogy on the Gerontology Research Group e-mail list just the other day:

I mean "entropy" as a law of physics has to do with aging in the same way that "gravity" has to do with the cause of airline crashes. It's a necessary but not sufficient condition. And even more than that, you wouldn't expect the FAA report in any given crash to spend much time discussing gravity, in trying to figure out the factors that are the cause of an airline crash. Similarly, in that sense, I think that discussion of entropy in discussions of aging, is wasting time.

In talking about the "causes" of aging, I presume we mean the differential and explanatory causes of aging. In that sense, invoking "entropy" is no more explanatory than "gravity" as a cause of airline disasters.

In terms of where I stand, I think it's fairly self-evident that if we can learn to repair an aging car, we can learn to repair an aging human. Yes, it's many, many times more difficult - but but both cars and humans are machines composed of many working parts. As such, the best thing we can do (as opposed to say, discussing entropy or gravity) is to accelerate research into understanding and fixing age-related damage to our health.