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← Life on earth started not once but twice?

Life on earth started not once but twice? - Comments

-TheCodeCrack-'s Avatar Comment 1 by -TheCodeCrack-

This announcement from NASA has me salivating. I'm sure the announcement will be interesting either way, but I just hope it's something big!

Wed, 01 Dec 2010 05:48:11 UTC | #556410

Neodarwinian's Avatar Comment 2 by Neodarwinian

I will think about it when they tell me about it.

My imagination is is up and running though.

Wed, 01 Dec 2010 05:50:44 UTC | #556411

ZenDruid's Avatar Comment 3 by ZenDruid

Apparently they found something interesting in Mono Lake, and can corroborate that with other discoveries...?

Wed, 01 Dec 2010 06:11:03 UTC | #556421

DocWebster's Avatar Comment 4 by DocWebster

One does stop to ponder, How many different times has life started here? How many environments such as this have harbored life then changed dramatically to snuff it out? Did our forebears at the birth of life have the field to themselves or were there extinctions that predate even speciation. I feel like a kid asking dad why the sky is blue again.

Wed, 01 Dec 2010 07:19:13 UTC | #556438

Canasian's Avatar Comment 5 by Canasian

I remember seeing a short clip which featured Felisa Wolfe-Simon few months ago. As I recall the film looked at various theories for the origins of life. I can't remember the name of the video but if someone could post it again that would be great.

Also, thanks for the links. We are waiting with bated breath for the exciting news.

Wed, 01 Dec 2010 07:28:21 UTC | #556440

JuJu's Avatar Comment 6 by JuJu

It looks like they found life in Mono Lake that can use arsenic for energy. They seem to imply that this is so unusual that it may be a new form of life. I would like to see more data before jumping on that band wagon. Life has a way of evolving to thrive in seemingly unlivable hostile environments. Now, if the life turned out not to have DNA, then they might be on to something, but until then I'm not going to hold my breath. Maybe because of this discovery they think they figured out how life could have began, or might have begun on some other planet. I guess we'll just have to wait and find out.

Wed, 01 Dec 2010 07:56:42 UTC | #556449

Canasian's Avatar Comment 7 by Canasian

My understanding on this is very rudimentary, so please correct me if I'm wrong. I don't think the organisms would lack DNA but rather be arsenic-based DNA which would be the first of its kind. To date I think all known life forms have phosphorus-base DNA.

I'm curious, if what they've found is arsenic-based DNA organisms then I'm assuming it would also contain the arsenic equivalent of RNA and ATP?

Wed, 01 Dec 2010 08:38:15 UTC | #556461

mmurray's Avatar Comment 8 by mmurray

I'm hoping for something like this:

The news conference will be held at the NASA Headquarters auditorium at 300 E St. SW, in Washington. It will be broadcast live on NASA Television and streamed on the agency's website at http://www.nasa.gov.

Participants are:
- Mary Voytek, director, Astrobiology Program, NASA Headquarters, Washington
- Felisa Wolfe-Simon, NASA astrobiology research fellow, U.S. Geological Survey, Menlo Park, Calif.
- Xjfgi Vaisxo, Galactic Ambassador, Tau Ceti IV
- Pamela Conrad, astrobiologist, NASA's Goddard Space Flight Center, Greenbelt, Md.

Maybe not. Just bugs.

Michael

Wed, 01 Dec 2010 08:38:47 UTC | #556462

event_horizon's Avatar Comment 9 by event_horizon

Comment 7 by Canasian :

My understanding on this is very rudimentary, so please correct me if I'm wrong. I don't think the organisms would lack DNA but rather be arsenic-based DNA which would be the first of its kind. To date I think all known life forms have phosphorus-base DNA.

That's my understanding also, and hence why I am very keen to find out what the announcement is.

I for one welcome my arsenic-based overloads...

Cheers,

Event Horizon

Wed, 01 Dec 2010 08:58:22 UTC | #556467

Schrodinger's Cat's Avatar Comment 10 by Schrodinger's Cat

The item in Astrobio leaves me somewhat puzzled.

They claim that finding a microbe that only used arsenic would indicate "that life evolved twice". Yet only two paragraphs before that, they say " have any of the Mono Lake organisms become so enamored of arsenic that they have found a way to incorporate it into their basic biological structures in place of phosphorus? ".....which implies an organism evolving to prefer arsenic to phosphorus. Clearly that is not the same as life evolving twice.

Wed, 01 Dec 2010 09:07:44 UTC | #556470

mmurray's Avatar Comment 11 by mmurray

Comment 10 by Schrodinger's Cat :

Clearly that is not the same as life evolving twice.

I was wondering about this as well. Maybe they are just going to argue that it could have evolved directly to arsenic instead of going via phosphorus ? I guess we just have to wait and see.

Michael

Wed, 01 Dec 2010 10:02:20 UTC | #556494

event_horizon's Avatar Comment 12 by event_horizon

Comment 10 by Schrodinger's Cat : .....which implies an organism evolving to prefer arsenic to phosphorus. Clearly that is not the same as life evolving twice.

Yes, I was puzzled by this also. Perhaps it just suggests that their research wasn't clear enough at the time for them to do much more than hedge their bets.

Wed, 01 Dec 2010 10:04:25 UTC | #556496

legal9ball's Avatar Comment 13 by legal9ball

Comment 10 by Schrodinger's Cat :

The item in Astrobio leaves me somewhat puzzled. They claim that finding a microbe that only used arsenic would indicate "that life evolved twice". Yet only two paragraphs before that, they say " have any of the Mono Lake organisms become so enamored of arsenic that they have found a way to incorporate it into their basic biological structures in place of phosphorus? ".....which implies an organism evolving to prefer arsenic to phosphorus. Clearly that is not the same as life evolving twice.

That was one of two possible outcomes of the research. The other was that the organism never used phosphorus "in the first place."

Wed, 01 Dec 2010 10:28:15 UTC | #556505

AtheistEgbert's Avatar Comment 14 by AtheistEgbert

The research isn't clear by what I read. But I suppose the consequences might be huge. If phosphorus is an essential part of DNA, and this life form uses arsenic, then it means we potentially have evidence of biogenesis within a unique environment.

It could mean evidence that life is created in such environments. All that is required is a chemical rich lake.

Of course, more evidence and analysis is required for such a claim.

Wed, 01 Dec 2010 10:44:14 UTC | #556515

PurplePanda's Avatar Comment 15 by PurplePanda

I find it unlikely that life only started once. I mean if the chance of life starting per unit time per unit volume was say 1 in a 1,000,000 (obviously it'd be higher, but for arguments sake) then you'd expect life to start once per 1000 seconds if you had 1000 volumes, or once per 1,000,000 seconds if you had 1 volume etc. But if the time*volume wasn't 1,000,000, you wouldn't expect it to only happen once. Maybe zero, maybe 100, maybe anything else.

It would just seem like a coincidence if it was only once.

Maybe a statistician can say what I'm trying to say better.

My guess would be it started many times but after the first time any tiny bits of organic matter that resulted would very quickly have been gobbled up by something which evolved from an earlier genesis (probably the first one).

Wed, 01 Dec 2010 10:50:18 UTC | #556521

JohnnyBosc's Avatar Comment 16 by JohnnyBosc

Comment 14 by AtheistEgbert

If phosphorus is an essential part of DNA, and this life form uses arsenic, then it means we potentially have evidence of biogenesis within a unique environment.

Not just biogenesis within a unique environment but possibly recent biogenesis. That place tends, every 10 million years or so, to blow up in humongous volcanic explosions leaving calderas 30 miles across and destroying all life within 1000 miles. That sounds quite conceivably like a fairly frequently reset biological clock. Then again, bacteria are hardy and, above all, ubiquitous and pervasive little things.

I'd go with

Comment 6 by JuJu

I guess we'll just have to wait and find out.

(and pretty much everything else he says in that post) but I'm not really holding my breath.

Wed, 01 Dec 2010 11:04:25 UTC | #556527

NealOKelly's Avatar Comment 17 by NealOKelly

Comment 15 by IndigoPanda

It would just seem like a coincidence if it was only once.

That would be a very peculiar coincidence indeed!

Wed, 01 Dec 2010 11:17:34 UTC | #556528

JohnnyBosc's Avatar Comment 18 by JohnnyBosc

Comment 15 by IndigoPanda

if the chance of life starting per unit time per unit volume was say 1 in a 1,000,000 (obviously it'd be higher, but for arguments sake)

Could you please elucidate upon the 'obviously'? Postulating, as is often done today, that life may be so unlikely as to only turn up on 1 out of a billion planets (planets are usually big things, with lots and lots of nooks and crannies where all sorts of things can be expected to happen) theoretically capable of sustaining it, then it would be very reasonable to expect, on probability grounds alone, a singular biogenesis on any given such planet. Or 'volume', if you will.

Wed, 01 Dec 2010 11:53:52 UTC | #556542

Alan4discussion's Avatar Comment 19 by Alan4discussion

that used arsenic instead,

..

Comment 1 by -TheCodeCrack-

This announcement from NASA has me salivating.

Careful! - That could prove fatal!

Wed, 01 Dec 2010 14:55:40 UTC | #556618

Alan4discussion's Avatar Comment 20 by Alan4discussion

Seriously though:

Comment 14 by AtheistEgbert

It could mean evidence that life is created in such environments. All that is required is a chemical rich lake.

Of course, more evidence and analysis is required for such a claim.

There is a vast amount of information even in the summaries here!

Wed, 01 Dec 2010 15:07:57 UTC | #556624

Rob Schneider's Avatar Comment 21 by Rob Schneider

I'm hoping the announcement involves the observation of a slight red-shift in light emanating from a planet (detected indirectly) 20 light years away, residing in a goldilocks zone, which might mean that arsenic based life is possible.

It will, of course, be accompanied by high definition graphical representations of this life (excuse, me... "what this life could possibly look like") and people all around the world will be asking how NASA got pictures of Arsenical bugs on a planet 20 light years away.

Sigh... I REALLY hope this is better than discovery of Gliese581d.

Wed, 01 Dec 2010 16:10:50 UTC | #556676

YXalr's Avatar Comment 22 by YXalr

Regarding the announcement, the rational part of my mind is expecting something that might have significance on studying the possibility of extra-terrestial life in the long run.

The rest of my mind is screaming: "UFOs! UFOs! UFOs! WOOO!"

Wed, 01 Dec 2010 16:19:33 UTC | #556681

crookedshoes's Avatar Comment 23 by crookedshoes

Can't wait for the rest of this to "flesh" out.

Wed, 01 Dec 2010 16:57:51 UTC | #556714

DavidMcC's Avatar Comment 24 by DavidMcC

What I don't understand is why there is no mention even of the obvious work needed to show that this isn't just life as we know it adapting to a toxin. This would obviously have involve studying the DNA of these microbes. Otherwise we cannot discount that they are just another kind of extremophile.

Wed, 01 Dec 2010 17:00:50 UTC | #556717

Jumped Up Chimpanzee's Avatar Comment 25 by Jumped Up Chimpanzee

I agree with Comment 24 by DavidMcC

Although very interesting, I have doubts over the inference that life may have started more than once. There is no mention at all in the article that these microbes have anything different to the DNA of other organisms. That's the first thing you would look for if you considered this was another tree of life, so why is it not mentioned? If they have the same DNA, then they surely could have (and probably did) evolve from the same tree of life as everything else.

Wed, 01 Dec 2010 17:14:18 UTC | #556726

Schrodinger's Cat's Avatar Comment 26 by Schrodinger's Cat

Comment 13 by legal9ball

That was one of two possible outcomes of the research. The other was that the organism never used phosphorus "in the first place."

That's still not the same as life evolving twice, unless the structure was so radically different to everything we know that one could automatically conclude that there could never have been a common predecessor. Given that the step between organic molecules and RNA is a huge one...I don't see how that claim could ( currently ) be made. It's not even clear if known life sprang up from one single chemical process at a single specific location, or that same process at a multitude of locations. The latter would be exactly the same as life evolving twice.

Wed, 01 Dec 2010 17:27:16 UTC | #556733

God fearing Atheist's Avatar Comment 27 by God fearing Atheist

Having read the main article link which stated the experiments began in 2009, and would take several months, and that we are in late 2010, and NASA have anounced a press conference, I can only conclude the experiments found something interesting, so interesting the results had to be repeated, and expanded. So I guess arsenic based life has been found. But enough of ignorant speculation. We will know tomorrow.

Wed, 01 Dec 2010 17:41:58 UTC | #556742

Canasian's Avatar Comment 28 by Canasian

Comment 5 by Canasian :

I remember seeing a short clip which featured Felisa Wolfe-Simon few months ago. As I recall the film looked at various theories for the origins of life. I can't remember the name of the video but if someone could post it again that would be great.

Also, thanks for the links. We are waiting with bated breath for the exciting news.

Okay, it was bugging me so I went and found the video clip. Might give some people a better picture of what Felisa's studying. Who can say "no" to something narrated by Morgan Freeman, enjoy!

Through the wormhole - How did we get here?

The link is for part 3 of 3, the whole episode was pretty interesting.

Wed, 01 Dec 2010 17:54:24 UTC | #556755

Enlightenme..'s Avatar Comment 29 by Enlightenme..

Arsenic based life might be a good thing for life overall, since peak Phosphorous is in about 2060 and it looks like we're gonna end up washing most of it onto the ocean floor.

Wed, 01 Dec 2010 18:05:46 UTC | #556761

katt33's Avatar Comment 30 by katt33

Go forth Science and endow us with wisdom.

Wed, 01 Dec 2010 19:23:56 UTC | #556803