What would be a Rosennean exobiology test?

[Tim Gwinn <***>]

 

In Nature this week, there is an article "Exobiology: It's life...isn't it?" which asks:

"Scientists find it hard enough to pin down evidence of early life on our own planet. How on Earth do we plan to determine whether life exists elsewhere?"

http://www.nature.com/news/2004/040712/full/430288a.html

[doi:10.1038/430288a]

 

 

The article goes on to examine the various attempts and proposals for some kind(s) of test(s) that could be placed aboard a spaceprobe and be able to give a definite (or at least, very strong) yes/no answer as to life beyond the Earth.

 

All these tests rest upon various kinds of chemistry, whether it be looking for by-products of reactions, isotope rations, amino acid chirality, etc.

 

But if Rosen is right that the key to "what is life?" is not in a particular chemistry, but in the organization of functional components, then none of these methods will necessarily tell us anything. If there are myriad physical ways for a function to be accomplished, then there are no guarantees that an exobiologic organism's functions will be accomplished in ways that our tests might detect. Further, since such tests cannot detect the actual functional components or their organization, the confidence from a positive or negative result from these tests would seem to be suggestive at best. To me, that lack of result confidence is not encouraging for spending millions of dollars and many years.

 

I propose the hypothetical question that NASA might ask if they were interested in the Rosennean view of "what is life?":

"1) could you come up with a test to place aboard a spaceprobe that would more definitively answer the exobiologic question by detecting function and its roganization, and 2) if so, what would that test look like?"

Anyone have any thoughts or ideas?

Tim