Exobiologists Cry - Biochemists Spring Massive Boner

[Metcarfre]

http://www.wired.com/wiredscience/2010/12/nasa-finds-new-life/
http://www.cbc.ca/technology/story/2010/12/02/bacteria-arsenic-dna-phosphorus-wolfe-simon.html
http://arstechnica.com/science/news/2010/12/bacteria-can-integrate-arsenic-into-its-dna-and-proteins.ars

When I first read the Wired article I was like, "HOLY CRAP ALIEN LIFE!!!". But no, it's bacteria that uses arsenic in lieu of phosphorus.

BOO NASA, BOOOOOOO!!!

[I X]

Aw, maaaan.

[Matt]

I was about to correct your headline to "Life discovered by nasa" but that works, I guess.

-m

[Danzama]

this is cool, not much more to say

[Theremin]

The comments in the first article are mildly headhurty.

[Metcarfre]

As a biochemist this is actually pretty rad. I'm gonna dig up and read this whole paper. I wonder if it uses arsenic in lieu of phosphorus in ATP?

[octopimpostor]

DUDE THATS SO TIGHT!!! Ive always Thought this was possible. arsenic could totally be a viable alternative to phosphate... ok well maybe i haven't but it makes sense... yeah maybe not that either... oh well its still pretty cool. Actually i took a class in genetics and it makes some sense, but way over my head still. Also it seems like they didn't find a new for of life, but instead showed a posibility of new life.

[Spatial Coffee]

How dare they not make a first contact with a hyper-advanced alien race!

[Lyinginbedmon]

I'm loving every minute of this news myself, I've had so many head-to-wall moments with people over the years trying to tell them that life, being the damn tenacious thing it is, borderline cannot be the same in two instances across the universe, that the makeup on Earth cannot be the only possible combination.

Basically I get to say "I told you so" to everyone I've ever had this argument with.

[octopimpostor]

How dare they not make a first contact with a hyper-advanced alien race! >=(

They have, but thats old news.

[Gordon Fearman]

I'm loving every minute of this news myself, I've had so many head-to-wall moments with people over the years trying to tell them that life, being the damn tenacious thing it is, borderline cannot be the same in two instances across the universe, that the makeup on Earth cannot be the only possible combination.

Basically I get to say "I told you so" to everyone I've ever had this argument with.

I hope those people are smart enough to realise that you didn't actually disprove them. It's not even alien life. Alien life may still be all Star Trek.

[Metcarfre]

I'm loving every minute of this news myself, I've had so many head-to-wall moments with people over the years trying to tell them that life, being the damn tenacious thing it is, borderline cannot be the same in two instances across the universe, that the makeup on Earth cannot be the only possible combination.

Basically I get to say "I told you so" to everyone I've ever had this argument with.

What argument is that?

If it's, "life doesn't need carbon!", try again.

[Lyinginbedmon]

No, it's "life doesn't need an Earth-like planet!"

[Metcarfre]

It depends what you mean by 'Earth-like'.

There's numerous 'extreme' environments where microbiota exist and thrive on Earth, that may have parallels on other planets. Bacteria existing, preserved, in blocks of salt, or thriving in ultra-high-salt-content lakes. High-pressure, high-temperature, sulfur dependent bacteria around undersea vents. Etc.

[Gordon Fearman]

No, it's "life doesn't need an Earth-like planet!"

Yeah, you didn't prove this at all. This life was formed on an extremely Earth-like planet.

[Lyinginbedmon]

*sigh*

I haven't proven anything. NASA has however shown that life doesn't need the same chemicals as most Earth life to survive. My issue before was that scientists only looked for Earth-like planets because they firmly believed that the way most life on Earth exists was the only way life could.

Now, yes, this new bacteria has evolved on Earth, the most Earth-like planet there is. That is not the point however. If it were, this would not be big news. The point is that life does not need the same chemicals, therefore my original gripe (that life elsewhere does not need to be at all like (most of) Earth's) is upheld.

[Ottoman]

The point is that life does not need the same chemicals, therefore my original gripe (that life elsewhere does not need to be at all like (most of) Earth's) is upheld.

I'm glad someone else gets this.

[Lyinginbedmon]

In brief, this discovery proves the viability of one of science fiction's greatest statements:

Life Jim, but not as we know it.

[JustAName]

Aaaand now I'm going to have that song stuck in my head for the rest of the day.

In other news, this is pretty rad, but not wholly unsurprising. If things evolved due to the (commonly prevailing; please no more pedantry) conditions on Earth, who's to say that other conditions couldn't also spawn life, just different life? So yeah, cool, but not a shocker.

[Master Gunner]

That life can spawn in extreme conditions is not overly surprising, what's surprising is that a lifeform managed to survive by replacing phosphorus in its DNA with arsenic, which produces byproducts that, if I understand correctly, were thought to be too unstable to allow for all the self-sustaining chemical reactions needed for the bacteria to survive. Another common thought experiment in regards to extra-terrestrial life is organisms that breath chlorine instead of oxygen, which Irregular Webcomic has a helpful annotation on, as well as all the associated difficulties with such a life form existing.

The possibility of life forming under radically different circumstances, using different building blocks, isn't new. Proving that it can and does happen, using elements that are less stable than what we use, is a shocker.

[Metcarfre]

Interesting to note that should arsenic fully supplant phosphorus in the DNA backbone, it would actually make this organism's 'DNA' more chemically dissimilar to DNA than RNA is to DNA (does that make sense?). Considering all currently characterized lifeforms use very similar forms of DNA to code their genetic information, this is a huge find.

[Digital Dolphin]

I know a lot of people will be disappointed with this news, but frankly it's more or less what I expected it to be. Also, I think it's really cool.

[goat]

As a biochemist this is actually pretty rad. I'm gonna dig up and read this whole paper. I wonder if it uses arsenic in lieu of phosphorus in ATP?

According to the summary over on Bad Astronomy our new little friend only utilizes arsenic as a replacement for phosphorous when phosphorous is no longer available. From the sounds of it, they grew it with no phosphorous at one point without any difficulty. So, I'd venture to guess that you're right about the ATP business (or else it has some hyper-efficient phosphorous recycling process).

(http://blogs.discovermagazine.com/badas ... f-arsenic/)

Interesting to note that should arsenic fully supplant phosphorus in the DNA backbone, it would actually make this organism's 'DNA' more chemically dissimilar to DNA than RNA is to DNA (does that make sense?). Considering all currently characterized lifeforms use very similar forms of DNA to code their genetic information, this is a huge find.

I dunno about dissimilar. I mean, in theory they should be relatively chemically analogous. It'll be a cherry, though, when we can figure out the mechanism of how it swaps the elements. My bet is on a swap out during replication, though a 1 to 1 swap during an S phase would be far cooler.

Also of interesting concern, is it capable of respiring using arsenic or does it just integrate it into its DNA* when it needs to?

*God, that feels like a line from CSI. Gonna take a little while to get used to saying that non-ironically.

[Metcarfre]

When the researchers added radio-labelled arsenate to the solution to track its distribution, they found that arsenic was present in the cellular fractions containing the bacterium's proteins, lipids and metabolites such as ATP and glucose, as well as in the nucleic acids that made up its DNA and RNA.[4]

Within the DNA extracted from GFAJ-1 cells starved of phosphorus, arsenic bonded to oxygen in the same way phosphorus bonds to oxygen in normal DNA, and found that when cultured in arsenate solution it grew 60% as fast as it did in phosphate solution — not as well, but still robustly.[4]

So it seems the organism inflicts a penalty from using arsenic in lieu of phosphorus (makes sense, otherwise everyone would do it).

[Gordon Fearman]

The point is that life does not need the same chemicals, therefore my original gripe (that life elsewhere does not need to be at all like (most of) Earth's) is upheld.

I'm glad someone else gets this.

I don't think anyone missed this.