A follow up to a previous post

Here is the previous post. Here is the follow-up: Something's amiss with aliens and arsenic

The stage was set by a coy news release from NASA that hinted at a discovery tied to the search for extraterrestrial life. The blogosphere went wild: Had bacteria been found on one of Saturn's moons, or life of some sort on Mars?

Instead, it was revealed this month in the journal Science that a strange bacterium lurking in the mud of California's Mono Lake had an uncanny ability to live off the poisonous chemical arsenic and even build it into its DNA.

News reports were dewy-eyed with wonderment over the study, which challenged conventional notions of what life on Earth — or elsewhere — could look like. Then, in short measure, came the scientific trash talk.

"Flim-flam." "Naive." "Fraudulent."

An embarrassing PR gaffe? Mediocre science that got undue attention because the buildup was too sexy to resist? A case of the peer-review process gone horribly wrong?

All played a role. But mostly, the wrangling is just a turbo-charged version of the kind of debate researchers have engaged in for centuries.

"The mythology of science is that you look down the microscope and you know what's what," said Harry Collins, who studies the sociology of scientific knowledge at the University of Cardiff in England. "But it's a matter of scientists slowly coming to a consensus, and it often takes a very, very long time to reach."