A Moment of Science

Arsenic-Based Life

Remember the "arsenic-based" micro-organism that NASA announced in December of 2010 had been found in the muck of Mono Lake in California? The microbe, named GFAJ-1, was said to use arsenic instead of phosphorus in its cellular machinery, even in its DNA. At the time, the news media speculated about a "shadow biosphere" and a "second genesis," a separate origin of life on earth. It was said that the biological "dogma" of CHNOPS — that carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur were fundamental to life — had been overthrown!

We mentioned this in our December 2010 service. But we said then that the facts remained somewhat sketchy and that the report was:

being spun as something that it's not. It's not a bacterium that uses arsenic as an energy source. It's not a bacterium that is "arsenic-based" or breaks the laws of chemistry or biochemistry. And it certainly is not a bacterium that we should suppose evolved separately from the rest of life on earth. Whether what it does is better described as "using" arsenic or "surviving" the effects of arsenic remains to be determined.

Well, Swiss researchers published last month — just last week in fact — their findings that the GFAJ-1 organism does not appear to substitute arsenic for phosphorus in its DNA or anywhere else and, in fact, cannot grow without phosphorus even if the levels of arsenic are high. The microbe, therefore "is an arsenate-resistant phosphate-dependent organism." And, as such, GFAJ-1 is not the result of a "second genesis," or a member of a "shadow biosphere," or anything that fundamentally overthrows the CHNOPS "dogma."

Now it's never any fun having your bubble burst, but the lead scientist on the original work responded by saying:

I think it's unclear whether this is the last word. [Felisa Wolfe-Simon, lead author of the original report on GFAJ-1, to The Washington Post]

Well, of course, in science there seldom is a "last word." But I think we can more admire the comment that the 19th Century British scientist and atheist Thomas Henry Huxley made when his own hopes about what he thought was a breakthrough in biology were dashed.

Interestingly, that occasion also involved what was thought to be microbial material, originating in sea floor samples, that was proposed to be the primitive form of life from which all others descended consistent with the then-new Darwinian theory. In 1868 Huxley gave this material the name: Bathybius haeckelii, the species name after his fellow scientist and evolutionist in Germany, Ernst Haeckel. But by 1875 — and remember, at that time chemical and biochemical methods were themselves primitive and no one knew anything about DNA and RNA — it was clear that Bathybius was no living thing and not a primitive progenitor of any living thing. Huxley was, of course, disappointed, but he had already noted, in 1870, in a lecture, appropriately enough, on "Biogenesis and Abiogenesis," that the falsification of some previous notions of spontaneous generation was an example of:

the great tragedy of Science — the slaying of a beautiful hypothesis by an ugly fact

It took Haeckel another 8 years to come around. Of course Bathybius and GFAJ-1 are — literally — small matters. Yet they fueled significant controversy. Is it any wonder, then, that some other ideas — those about deities having life-and-death power over humans, deities who supposedly make land grants and who are made unhappy by various behaviors relating to sex, reproduction, and a whole bunch of other things — that such ideas held by millions including learned scholars constantly engaged in defending those ideas would fuel controversies several orders of magnitude more enduring and violent? It is sad but true that people get emotionally attached to ideas, especially ideas that involve or relate to stories that flatter us by appealing to our sense of wonder and our need to feel important.

This is of obvious significance to us as Freethinkers, because we don't celebrate religious faith, but religious doubt. We like to kill "beautiful hypotheses" with "ugly facts" because we find the ugliest facts to be more beautiful than any hypotheses not supported by such facts. Or, at any rate, we flatter ourselves that this is the case.

Don't get too attached to ideas derivative of the only really important one, that facts and reason are our best hope for making sense of things.