NASA finds new form of life (for real).

[Muffin]

NASA’s Felisa Wolfe-Simon (who found GFAJ-1) said “It’s wierd!”

Another of the NASA panel members used the Horta to explain it.

And some fool reporter said people are disappointed in learning that it is not ET.

[bouv]

@Stranger_On_A_Train

The linked article provides no details on the genetic makeup of the bacteria found, but I would estimate it far more likely (if the discovery is found to be genuine) that the bacteria is the result of a mutation that substituted arsenic for phosphorous rather than a completely unique development of life.

I don’t think it is…I mean…how can you mutate to suddenly substitute arsenic in your DNA?

I’m not too keen on molecular biology, but on another forum I was given this analogy:

Imagine all life on Earth is made with Lego bricks (the phosphorus in your DNA.) Everything uses Lego bricks. To make new life, you can add in all the Lego bricks you want, change them around, etc…, but you can only use Lego bricks. Now, we found out something that uses Megablocks. Although Megablocks are similar, they are not Lego bricks…no amount of adding, rearranging, removing, etc… the Lego bricks will make something with Megablocks, that thing must therefore have started with Megablocks.

I have no idea if it’s an apt analogy, but it did make it make sense to me.

[Lord_Ashtar]

@bouv

Imagine all life on Earth is made with Lego bricks (the phosphorus in your DNA.) Everything uses Lego bricks. To make new life, you can add in all the Lego bricks you want, change them around, etc…, but you can only use Lego bricks. Now, we found out something that uses Megablocks. Although Megablocks are similar, they are not Lego bricks…no amount of adding, rearranging, removing, etc… the Lego bricks will make something with Megablocks, that thing must therefore have started with Megablocks.

That sounds an awful lot like Intelligent Design to me. Just because we can’t (immediately) imagine how the Legos got replaced with Megablocks doesn’t mean we can’t later understand how it happened.

[Ogre]

It sounds to me as if this bacteria simply has an adaptation to detoxify arsenic in most of its biochemical pathways. The fact that it can incorporate arsenic in its DNA is not necessarily surprising, since1) arsenic is similar to phosphorus, and 2) all it would really substitute is the phosphate backbone, not any of the sugars or the nucleotide bases. I would imagine that the larger atomic size might cause some “spacing” problems with polymerases, etc. attempting to bind to and read the unzipped DNA (perhaps partially explaining the lower affinity for arsenic)

[appleciders]

@bouv

I don’t think it is…I mean…how can you mutate to suddenly substitute arsenic in your DNA?

I’m not too keen on molecular biology, but on another forum I was given this analogy:

Imagine all life on Earth is made with Lego bricks (the phosphorus in your DNA.) Everything uses Lego bricks. To make new life, you can add in all the Lego bricks you want, change them around, etc…, but you can only use Lego bricks. Now, we found out something that uses Megablocks. Although Megablocks are similar, they are not Lego bricks…no amount of adding, rearranging, removing, etc… the Lego bricks will make something with Megablocks, that thing must therefore have started with Megablocks.

I have no idea if it’s an apt analogy, but it did make it make sense to me.

That sort of overstates the point. Phosphorus is not a large part of our physical makeup; it’s only about 1.2% by mass, rather than the Lego example, which implies that most of our body is phosphorus. Arsenic also behaves in a very similar way to phosphorus chemically, so it’s not much of a stretch to imagine that an organism might use arsenic instead when it lives in an arsenic-rich environment, except that arsenic is extremely toxic to just about every form of life we know. Finding this species, that not only tolerates it but actually uses it is pretty damn interesting, but it’s not that different; in terms of Legos, this organism has an adapter that lets you plug Megablocks in every so often, but is basically built of Legos. Very interesting, but not a slam-dunk abiogenesis. It might be one, but we’d have to sequence the DNA to have any real idea, and we may never know for sure.

[Juliette_Culture_Junkie]

AFAIK every known cell metabolizes ATP (adenosine triphosphate). Any clue what this critter uses as its main energy source? Any ideas about a non-phospholipid cell membrane, for that matter?

[BigT]

This is just what tickles me:

Discovered in the poisonous Mono Lake, California, this bacteria is made of arsenic, something that was thought to be completely impossible. While she and other scientists theorized that this could be possible, this is the first discovery.

So it’s both thought to be completely impossible, and theorized to be possible.

[dzero]

Considering the fact that water made from deuterium rather than normal hydrogen is poisonous, I think the fact that this bacteria uses a completely different element in place of phosphorous is a pretty big deal. Even if it happens to be in the same column of the periodic table, there will be at least small differences in how it reacts with other compounds and has to have some affect on the structure of its DNA. However that doesn’t mean that the rest of the cellular machinery has to be that different. As long as the DNA can be read and translated into proteins, everything else should look pretty much the same.

[Le_Ministre_de_l_au-dela]

A recent episode of RadioLab talked about a toxic lake in Montana with a bacterium thriving in it when the bacterium should have just died outright - I think the episode was called ‘Oops’ and I think I still have it archived somewhere…

[ToeJam]

Here’s a nice explaination of what’s sort of going on:
“It’s not an arsenic based life form” by PZ Myers, for a biology perspective.

[Autolycus]

@bup

I wonder if the DNA chain goes clockwise or counter-clockwise.

Forget that. I want to know if it flips the toilet paper over or under.

[Ogre]

@ToeJam

Here’s a nice explaination of what’s sort of going on:
“It’s not an arsenic based life form” by PZ Myers, for a biology perspective.

Pretty much what I said.

[Ken001]

@ToeJam

Here’s a nice explaination of what’s sort of going on:
“It’s not an arsenic based life form” by PZ Myers, for a biology perspective.

Damn! Just when I was getting excited about this. Myers explanation is calm and matter-of-fact, pointing out that the NASA research is interesting but not unknown to biologists.

A wet blanket indeed.

[Smeghead]

Yep. Very cool; not earth-shattering by any means. Still. I wish it was my paper…

[cochrane]

@Thudlow_Boink

It’s life, Jim, but not as we know it.

@Wheelz

Speaking of Star Trek, didn’t they have an episode with a creature that had silicon in place of the carbon? No so far-fetched after all…

Though I’m left wondering what NASA was doing rooting around a lake in California.

@Leaffan

That would be the Horta.

Dammit, Jim! I’m a doctor, not a bricklayer.

[brujaja]

@Stranger_On_A_Train

Fox News long ago passed the self-caricature threshold with their trademarked “Fair and Balanced” slogan. At this point, they’re sort of a post-post-Modern, post-ironic, post-infotainment performance art exhibit.
Stranger

Well said.