Thursday, December 9, 2010

Claims regarding life based on arsenic questioned


We have seen this movie before: scientists hold a press conference to announce much-hyped results (cold fusion in 1989, the Martian rock with signs of life in 1996). Then other researchers check out the claims, which proceed to vanish like a rabbit in a magic show. We have also seen the movie in which a leading science journal publishes a paper making extraordinary claims only to see them shown to be seriously flawed, as in recent claims about the genetic basis for longevity in Science, that other scientists raised serious doubts about.

So the concerns being raised about last week’s press-conference announcement, and Science paper, by researchers at NASA’s Astrobiology Institute, the U.S. Geological Survey, and elsewhere that bacteria scooped from Mono Lake are able (when grown in the lab) to incorporate arsenic rather than phosphorous in its nucleic acids and enzymes are not exactly surprising. The thrust of the claim is that this represents a new way to live—that although all previously known forms of life on earth use phosphorous in the backbone of their DNA and RNA, this bug can use arsenic, which is usually poisonous. That challenges the dogma that life requires the Big 6: oxygen, carbon, hydrogen, nitrogen, phosphorus, and sulfur. If there are other ways to be alive, the likelihood of life on other planets rises. [...]

No comments :

Post a Comment

please use either your real name or a pseudonym.