Arsenic-based lifeforms discovered on Earth.

I'm not sure I understand the significance of this, though I'm sure it's important. Any science-types out there able to fill us in?

Here we go. This seems like a better article.

edited 2nd Dec '10 11:32:47 AM by Gelzo

I should be more use than I am, being a bioscientist. Nonetheless, this might help. Its what phosphorus is used for in the body. Essentially phosphorus is essential for the building blocks of DNA and RNA, along with bone structure and... all kinds of things really. I'd be interested in finding out how Arsenic can replace it.

It means that more forms of biochemistry are possible than we thought, which in turn means more possibilities for aliens.

Fascinating. But for earth based problems are there any uses for these bacteria? Arsenic is a deadly poison afterall.

The significance is that up until now, all known forms of life used phosphorous and phosphate chemicals to construct DNA, RNA, and amino acids. So this organism works in a way different than all other known life, because it substitutes arsenic as the building block.

^^It's not like that. Taking straight phosphorus would probably kill you too, and arsenic is present in humans in small amounts already (iirc). Apparently it used to be used as a stimulant, even.

edited 2nd Dec '10 11:47:47 AM by Tzetze

I knew about the significance just also wondering if there was any others. So this is organic life using an atypical compound in it's biology. So does that mean Arsenic replaces Phosphorous I'n ADP and ATP as well? The artcike only mentions genetic material.

They were mentioning in the live feed I saw that AMAS, or Adenosine monoarsenate, was spontaneously created.

So it's clear that these bacteria can't be heterotrophs as no other organisms would have the Arsenic needed to make thier compounds.

It would appear to be so. These bacteria would most likely be autotrophic chemosynthetics.

Or perhaps Chemotrophs. Regardless these things obviously will need their own Domain if scientists don't make another taxa higher than Domain. We're just calling them bacteria for convenience.

edited 2nd Dec '10 12:50:25 PM by RhymeBeat

Ed Yong at Not Exactly Rocket Science has a great article on this that clears several things up.

They don't replace all their phosphorus with arsenic, and in fact they apparently actually grow better on phosphorus. They are closely related to other lifeforms - they're not something completely new, they're bacteria that have adapted to use arsenic instead of phosphorus.

It means that the phosphate used to create the strong sugar-phasphate backbone of DNA and RNA would be replaced by arsenic... bloody hell, that is a mind boggler. It means that every time you make ATP into ADP instead, it would be ATA to ADA instead. Your bones would be partly made up of Arsenic, messengers in your body would be made of arsenic... the list goes on. It has huge implications.

Still needs water to function mind.

EDIT: On second thoughts, read ^that.

edited 2nd Dec '10 1:01:52 PM by GameChainsaw

OK. That clears that up. So its kind of similar in this sense to termites, organisms that can do things its evolutionary cousins can't do but are still fundementally the same type of organism. And it does prove that given the right adaptation life can substitute arsenic for phosphorus which will be usefull in a search for other forms of life.

Alien Invasion in progress.

Oh, that's so cool.

Oh god. WOWIE WOW does not even begin to cover it!

This is still a carbon based organism though. An arsenic based lifeforms must substitute their carbons with arsenic.

Even if the thread title is a misleading and the discovery is overhype (I was really expecting an entirely new life form, not just a adapted one) This is still a great discovery. Thing like this have never been predicted before right? Life is really amazing, isn't it?

Depends on what you mean by predicted.

The idea that life might have a different chemical basis isn't exactly a revolutionary idea, but this is a proof of concept, essentially, which IS big new.

As expected, XKCD has already made a joke about it.

My knowledge of chemistry doesn't extend beyond anything learned in grade school, but if the phosphorous was replaced with arsenic in the organism's DNA, wouldn't it have to retain the same bond structure that the phosphorous had to keep the DNA from becoming misshaped?

It should, since both elements are similar in structure and have the same amount of valence electrons.

Anyone tried it with antimony yet?