Microbes use arsenic in their DNA: Proves phosphorus is not required for life

Re:Microbes use arsenic in their DNA: Proves phosphorus is ... by jerf on Thursday December 02, 2010 @04:41PM (#1963782)

But how is that a change? We already knew that to the point that we're looking at non-Earthlike planets. We're already looking for life on Titan and Europa, already looking on Mars to see if it had life. We're already talking about life on that tidally-locked mega-Earth that came up a couple of months ago, with otherwise-respectable scientists saying it's 100% likely [1]. We're already not convinced that life has to start exactly as Earth does.

If it's "different", what's the actual difference? What actually changed?

[1]: http://www.space.com/scienceastronomy/earth-like-exoplanet-p...

[ Parent | on HN ]

Re:Microbes use arsenic in their DNA: Proves phosphorus is ... by noodle on Thursday December 02, 2010 @04:56PM (#1963834)

no. we already theorized that, we didn't know. we didn't have proof. now we do; now we know. the actual tangible differences are likely going to be in funding, research direction, and scope of effort on the topic. who knows what future research will generate off of this?

no, the world hasn't changed. sorry. not yet, at least. but its kind of like watching the moon landing in '69 and scoffing at it because you knew it was coming, you've been reading about NASA working on it for years in the paper.

[ Parent | on HN ]

Re:Microbes use arsenic in their DNA: Proves phosphorus is ... by jerf on Thursday December 02, 2010 @05:06PM (#1963866)

You're badly misunderstanding my point. I'm not saying this isn't interesting. I'm saying this isn't actually all that interesting when it comes to the Great Questions. It doesn't significantly expand where we already thought life could be. It has not yet established that it is anything other than another evolution of Earth life, which would be a big deal, and from the sounds of it that's still what it is, an adaptation.

This isn't some amazing announcement with profoundly unsettling implications for life in the Universe. It's another in a long series of announcements about how our understanding was limited about how far Earth life could travel. It's roughly similar to how we found non-photosynthetic life around the ocean vents [1], or the recent discoveries of strange life several miles underground [2], or the sky bacteria [3]. I think quite a few people here are not understanding just how many similar discoveries have already been made, we moved on from "all life in the universe will look just like the standard sun-powered ecosystem we live in" quite a while ago.

I guess you could say to the extent this is amazing, we've already been amazed this way. It's cool, but it's a discovery that fits quite comfortably with a number of other interesting discoveries. We're not going to be talking about this in another year. (Except possibly because once people start looking for more examples of this sort of thing I'd lay money they find them.)

[1]: http://en.wikipedia.org/wiki/Hydrothermal_vent#Biological_co...

[2]: http://www.livescience.com/animals/061019_otherworldly_bacte...

[3]: http://www.wired.com/science/planetearth/news/2008/02/bacter...

[ Parent | on HN ]