Re: your mail

Gene Godbold (
Sat, 10 Aug 96 10:54:53 EDT

> As for the evidence of life, I am truly disappointed after all the hoopla
> (and prior rumors). You must remember that some meteorites are loaded with
> amino acids which were all produced by chemical reactions in space, and not
> by living beings. The real evidence, in my book, would come if they find
> racemization (handedness) in amino acids. In laymans' terms, left-handed
> amino acids are a characteristic of all life on Earth. Random handedness
> indicates non-living chemical processes. A dead-ringer for life on Mars
> would be to find a population of right-handed-only amino acids. That would
> truly indicate extraterrestrial life.
> For the moment, I remain very skeptical that they have found evidence for
> life, though the meteorites are definitely from Mars.
> --Roger C. Wiens

I read a short newspaper article yesterday in which a geochemist disputed
the conclusion of life in the meteorite on the basis of the ratio of
sulfur-32 to sulfur-34 --apparently the ratio changes as a result of (at
least) terrestrial biochemistry. There is a later comment to the effect
that Martian life might not have the same effect on the sulfur ratio.
Being no expert on metabolism, why should the ratio change, assuming
earth-like biochemistry? Would it be reasonable to assume that Martian
life could differ?

Gene Godbold

(soon to be)
Dept. of Infectious Disease
UVA School of Medicine