Reader Steven Young (RDR, Nov. 13), with reference to my definition of life (in my Nov. 8 column Looking Up) as “self-replicating chemistry,” correctly observes that to define life adequately is a tricky task. I would reply that no two- or three-word definition could wholly capture the nature of the thing, but I think most scientists would agree that if one had to do it in two or three words, those words are a reasonable choice. All life on this planet is based on DNA, and DNA is surely self-replicating chemistry at the molecular level.
As for the definition’s being “Godless,” one must realize that even among microbiologists, biochemists, and geneticists, some people think the pageantry of life is guided by supernatural causes and some do not, this ultimately being a matter of introspection and personally chosen belief, and a matter outside the purview of science.
The world is replete with different religions which are often incompatible, but DNA works the same all over the planet. Whether it works the same way on other planets, we hope someday to discover.
Donald R. Burleson