More Stars, Types of Life, Than Previously Thought

Today’s New York Times had not one but two interesting science articles.

The first is the discovery of a new type of bacteria in Mono Lake not far from here in California. What makes it unique (compared to every other type of life on earth) is that it has DNA, but the “ladder” structure of the helix is formed using atoms of arsenic instead of the phosphorus used in the DNA in you and me and whatever we had for dinner. This is truly amazing, and raises profound questions about evolution. What does it mean that a nontrivial molecule like DNA can either (a) evolve twice, or (b) evolve once, but then survive such a profound alteration? (Interestingly, one of the scientists involved is Paul Davies, who won the Templeton Prize in 1995.)

The second interesting article is a reassessment of the number of stars in the universe. I’m always fascinated by this sort of thing, even when it’s just pushing back the frontiers of knowledge. But consider this for a moment:

“We may have to abandon this notion of using the Milky Way as a template for the rest of the universe,” Dr. van Dokkum said.

Ouch! That had to smart. Copernicus proposed that the earth revolves around the sun, rather than the reverse. Since then, it’s been a matter of (ahem) faith among scientists that there’s nothing at all exceptional about us or our place in the universe. But we keep finding exceptions to that rule.

Updated (Dec. 10): apparently there are serious flaws in the study that purported to find evidence of arsenic-based DNA. I tried to read Rosie Redfield’s article, but about halfway down the page it got too dense for me to understand. There’s a point waiting to be made here about the responsibility of the science press not to hype things until they’ve been subjected to proper peer review, because people like me just aren’t as scientific as Rosie Redfield and Paul Davies.