Scientists find arsenic-based life

[Balta1701]

I'm a little concerned all of a sudden. These things might be in my bloodstream.

Hours before their special news conference today, the cat is out of the bag: NASA has discovered a completely new life form that doesn't share the biological building blocks of anything currently living in planet Earth. This changes everything. Updated.

 

At their conference today, NASA scientist Felisa Wolfe Simon will announce that they have found a bacteria whose DNA is completely alien to what we know today. Instead of using phosphorus, the bacteria uses arsenic. All life on Earth is made of six components: carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. Every being, from the smallest amoeba to the largest whale, share the same life stream. Our DNA blocks are all the same.

 

 

But not this one. This one is completely different. We knew that there were bacteria that processed arsenic, but this bacteria—discovered in the poisonous Mono Lake, California—is actually made of arsenic. The phosphorus is absent from its DNA. The implications of this discovery are enormous to our understanding of life itself and the possibility of finding beings in other planets that don't have to be like planet Earth.

News conference in 5 minutes or so at www.nasa.gov/ntv.

[Balta1701]

That's the most interesting pronunciation of "pH" I've ever heard.

[FlaSoxxJim]

Dang webcast seems to be frozen for me. Probably a lot of people logged on.

 

Jumping the gun on this discussion, do you all think the Mono Lake bacteria are evidence of panspermia and arrived here from an extraterrestrial point of origin, or are they evidence that abiogenesis occurred on at least two distinct occasions on Earth?

 

Either way, if they found what they think they found, I really think it is an utterly profound discovery.

 

 

[bigruss]

That's the most interesting pronunciation of "pH" I've ever heard.

That lady was annoying to listen to.

 

Still interesting material for a person who couldnt understand chemistry or biology for his life.

[Balta1701]

Dang webcast seems to be frozen for me. Probably a lot of people logged on.

 

Jumping the gun on this discussion, do you all think the Mono Lake bacteria are evidence of panspermia and arrived here from an extraterrestrial point of origin, or are they evidence that abiogenesis occurred on at least two distinct occasions on Earth?

 

Either way, if they found what they think they found, I really think it is an utterly profound discovery.

I think the answer is probably neither. From what they presented...it sounds like the DNA of these things seem at least quasi-ordinary, except for the presence of arsenic.

 

Unless their really cool animation was inaccurate (which would be really F***ing disappointing because that was a cool animation), normal DNA structure, normal DNA basically, except with Arsenic substituted 1:1 for Phosphorus.

 

My guess would be that these things are basically bugs that existed in a high arsenic, low-P environment, and a mutation allowed it to make use of As instead of P.

[Balta1701]

Dang webcast seems to be frozen for me. Probably a lot of people logged on.

Oh, try opening the Windows media version. Quicktime wouldn't work, but that one opened fine.

[Balta1701]

I think one of the guys just used the phrase "Demon sheep".

 

Awesome.

[FlaSoxxJim]

I think the answer is probably neither. From what they presented...it sounds like the DNA of these things seem at least quasi-ordinary, except for the presence of arsenic.

 

Unless their really cool animation was inaccurate (which would be really F***ing disappointing because that was a cool animation), normal DNA structure, normal DNA basically, except with Arsenic substituted 1:1 for Phosphorus.

 

My guess would be that these things are basically bugs that existed in a high arsenic, low-P environment, and a mutation allowed it to make use of As instead of P.

 

I never could get the feed.

 

You are likely right if every other aspect of the DNA structure is the same except for arsenic substitution is identical. Still, what a neat discovery.

 

[Balta1701]

Necessary NASA Press conference Star Trek reference: 0 hours, 54 minutes in.

[GoSox05]

Is this good or bad. I thought it sounded pretty cool, but not if demon sheep are involved. I don't know.

 

 

[Balta1701]

Is this good or bad. I thought it sounded pretty cool, but not if demon sheep are involved. I don't know.

There is no sense in which this is bad. Unless you're on the committee that the lead author applies to for funding, because your life just got a lot busier.

[BigSqwert]

There is no sense in which this is bad.

What if you're a creationist?

[ChiSox_Sonix]

What if you're a creationist?

 

I don't think this by itself would refute those beliefs though? It could be easily explained away.

[almagest]

I don't think this by itself would refute those beliefs though? It could be easily explained away.

Yeah, "creation science" is pretty good at making up things.

 

[NorthSideSox72]

I always thought it was a world-is-flat sort of belief in the scientific community that all life must be carbon-based. Just because that is what we know, that doesn't mean a damn thing about what other things could exist somewhere else. It may make those things probable, but to write off anything else entirely just seemed ignorant to me.

 

[BigSqwert]

I always thought it was a world-is-flat sort of belief in the scientific community that all life must be carbon-based. Just because that is what we know, that doesn't mean a damn thing about what other things could exist somewhere else. It may make those things probable, but to write off anything else entirely just seemed ignorant to me.

I've always felt the same way.

[Iwritecode]

I always thought it was a world-is-flat sort of belief in the scientific community that all life must be carbon-based. Just because that is what we know, that doesn't mean a damn thing about what other things could exist somewhere else. It may make those things probable, but to write off anything else entirely just seemed ignorant to me.

 

So if we ever do find intelligent life it probably won't look like what we saw on old star-trek episodes then huh?

[StrangeSox]

I always thought it was a world-is-flat sort of belief in the scientific community that all life must be carbon-based. Just because that is what we know, that doesn't mean a damn thing about what other things could exist somewhere else. It may make those things probable, but to write off anything else entirely just seemed ignorant to me.

 

I don't know if it was/is so much "all life MUST be carbon-based" or more "all known life IS carbon-based." This is a classic Black Swan example.

[NorthSideSox72]

I don't know if it was/is so much "all life MUST be carbon-based" or more "all known life IS carbon-based." This is a classic Black Swan example.

1. I've heard it said by some in the scientific community as an absolute - which was what I'd call ignorant.

 

2. Its not a Black Swan in the broad scope - only on Earth, where we have a decent handle on life forms. If you are talking about truly universal here, then there can be no black swan because we don't know the data set.

 

[FlaSoxxJim]

Don't forget though, these newly described bacteria STILL ARE carbon based. a single atom (phosphorus) has been swapped out in favor of another (arsenic) in the backbone of the DNA molecule. The bacterium itself is still an organic (carbon-based) life form.

[StrangeSox]

1. I've heard it said by some in the scientific community as an absolute - which was what I'd call ignorant.

 

2. Its not a Black Swan in the broad scope - only on Earth, where we have a decent handle on life forms. If you are talking about truly universal here, then there can be no black swan because we don't know the data set.

 

Black Swan in the scope of the historical black swan story--Europeans knew nothing of black swans before the 18th century, so it was a safe assumption that all swans were white. We haven't seen life with arsenic instead of phosphate until recently, so this arsenic substitution is a "black swan".

[StrangeSox]

Several blogs on the discovery:

http://blogs.discovermagazine.com/notrocke...t-about-aliens/

http://blogs.discovermagazine.com/loom/201...nic-and-aliens/

 

And the paper, for anyone with access to Science:

http://www.sciencemag.org/content/early/20...science.1197258

[FlaSoxxJim]

I need to take time to read the Science article, but the Loom blog points out something to keep in mind.

 

The Mono Lake bacteria probably don’t actually exist in an arsenic-based form in nature, since they grow much faster on phosophorus. They’re aliens, but aliens in the same way unnatural E. coli are, thanks to our intervention. But Wolf-Salmon’s results suggest that life based on arsenic is at least possible. It might even exist naturally in places on Earth where arsenic levels are very high and phosphorus is very scarce.

[Balta1701]

I need to take time to read the Science article, but the Loom blog points out something to keep in mind.

I'd bet there's a reasonable chance they actually do exist as As-rich bacteria in nature, if the chemist who presented yesterday is worth his salt. He argued quite convincingly that in a normal DNA chain, anything bonded with As instead of P is a particularly weak link and leaves the chain easily severed, requiring repair. The suggestion I got was that this substitution and weakening of P-rich structures was the main mechanism of As poisoning in normal life. Getting around this problem would probably require some mechanism by which either the chain is strengthened/protected by another cellular component, or a mechanism by which breaks are rapidly repaired so as to not become systemic and kill the organism. Both of those seem to me to be adaptations that would require significant expenditures of energy to maintain. As such, if the bugs weren't living as As-rich bacteria in nature, there's no reason for them to maintain this adaptation over multiple generations; it'd be a large selective disadvantage because it'd be such a large waste of energy.

[StrangeSox]

Is it worth noting that As and P are the same valence number?