Gizmodo: NASA to announce possible 'alien' life form?

[Corcaigh]

http://gizmodo.com/5704158/nasa-finds-new-life

2pm today ...

Speculation it's a bacteria with different DNA to the rest of life on Earth.

[USS Redskins]

It will never live up to the hype on the internet. If its just some chemical thing - boring... like the Mars rock from the late 90's that turned out to be bogus... I need to see a crashed spaceship and a dead ET.

[JMS]

It's not extra terestrial? Why is NASA even involved? I understand why they are interested. it's odd they are making the announcement.

[fullnelson9999]

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.

Oh really? No **** Sherlock.

I've never understood the reasons why people think that all lifeforms must be carbon based.

[JMS]

Oh really? No **** Sherlock.

I've never understood the reasons why people think that all lifeforms must be carbon based.

Granted but did you ever think a lifeform could be arsinic based. That's the question?

[PeterMP]

Oh really? No **** Sherlock.

I've never understood the reasons why people think that all lifeforms must be carbon based.

It is carbon based.

It uses As instead of P in its DNA. We have phosphate groups connecting our bases in the DNA. It uses arsenate.

I'd guess, but don't know, it will use As in its RNA as well.

The real interesting question to me is ATP, which is chemical energy for every known living organism on Earth and used by lot's of enzymes and processes in all known living organisms. If it is using ATAs instead, that's really amazing. That's a huge evolutionary over haul of lot's of processes.

But it still contains larges amount of C. The As has replaced P; not C.

non-C based life would be very surprising because C makes lot's of different types of chemical bonds to lot's of different types of atoms. As is right below P on the periodic table and have similar chemistry. You could similarily imagine a less O based life where S was used in some cases instead of O.

The problem with C is that Si isn't really that chemically similar.

If anything other than C, we are most likely to see N/P based life:

http://en.wikipedia.org/wiki/Hypothetical_types_of_biochemistry

http://www.blc.arizona.edu/molecular_graphics/dna_structure/DNA_12bp_WF.GIF

Everywhere you see a yellow, that's a P. Instead of a P, they have As. The red is oxygen, the gray is carbon, the blue is nitrogen, and they don't show the H.

[JMS]

It is carbon based.

It uses As instead of P in its DNA. We have phosphate groups connecting our bases in the DNA. It uses arsenate.

I'd guess, but don't know, it will use As in its RNA as well..

I was just about to make that distinction..... NOT..

Good job, you explained that very well. Even I understod it.

[Arsenic]

I read something about photosynthesis on Arsenic found in Titan (Saturns moon).

[sly]

Regardless of what type of "life form" they find, I'm pretty excited. Considering all the planets WITHOUT life, Earth is a statistical anomaly... but you'd think there has to be SOME form of life on other planets. Finding one with the capability to evolve would just be amazing (finding actual alien species would be life altering).

Another thought... what if humans are actually the "aliens" and end up visiting primitive beings thousands of years from now?

[Conn]

Regardless of what type of "life form" they find, I'm pretty excited. Considering all the planets WITHOUT life, Earth is a statistical anomaly... but you'd think there has to be SOME form of life on other planets. Finding one with the capability to evolve would just be amazing (finding actual alien species would be life altering).

Another thought... what if humans are actually the "aliens" and end up visiting primitive beings thousands of years from now?

If human society makes it that long. I don't really see it.

But that's definitely a possibility. Why not?

I think people like to assume that we'll be "visited" because it would HAVE to be aliens with FAR superior technology doing the visiting.

But thousands of years from now, if we're still around? Sure. Its possible.

[Predicto]

I've never understood the reasons why people think that all lifeforms must be carbon based.

Posting before Larry can...

[JMS]

Regardless of what type of "life form" they find, I'm pretty excited. Considering all the planets WITHOUT life, Earth is a statistical anomaly... but you'd think there has to be SOME form of life on other planets. Finding one with the capability to evolve would just be amazing (finding actual alien species would be life altering).

Another thought... what if humans are actually the "aliens" and end up visiting primitive beings thousands of years from now?

Isn't it interesting that two sentiate humanoid life forms developed on earth in parrallel and coexisted for centuries

[Predicto]

Isn't it interesting that two sentiate humanoid life forms developed on earth in parrallel and coexisted for centuries

I don't generally consider red-staters to be sentient, but I guess you can if you want to.

[Larry]

Posting before Larry can..

Too late.

I posted in the other thread on the same subject, and decided not to duplicate it, here.

[Predicto]

Too late.

I posted in the other thread on the same subject, and decided not to duplicate it, here.

NOOOOO!!!!!!!

[Burgold]

Star Treking across the Universe

We're always going forward

cause we can not find reverse

(Don't know what that has to do with anything, but that song always made me chuckle)

On topic, this is cool stuff. Thanks for bringing it to the board's attention.

[Vilandil Tasardur]

This is one of the most exciting things ever!

One question I ask myself, is how long ago did this bacteria pop up. It's easy to assume that because it is simplistic, that it is old, but that need not be the case. Crocodiles have existed for millions of years, but if a new species branches off of the crocodile tree today, it obviously is not very old. This species would be closely related to all other members of the crocodile line, without being nearly as old as the others.

Clearly, these bacteria belong very low on the evolutionary tree of life. However, the bacteria could have popped up billions of years ago when the first bacteria were all differentiating, or it could have popped up last year. I'm real, real curious.

[Larry]

Now, for those of us who need things explained to us . . .

Can anybody explain why this is important?

I mean, based on the tiny portion of High School biology that I still retain, my knowledge of DNA is that it's this big, huge, molecule, and that there's this one place on that molecule where one of four atoms can go. The big, huge, "base" or "carrier" part of the molecule can attach to two other bases.

Maybe an analogy would be to think of a railroad flatcar. The flatcar is huge, and complicated, and can attach to two other flatcars. (Any two flatcars.) One at each end.

The flatcar can carry one atom, from a menu of four choices. (I memorized what the four choices were, for a test. And immediately forgot them.)

There's a second string of flatcars, parallel to the first. (Imagine them suspended from the ceiling.) However, for each "payload" on the train on the floor, there is one and only one payload that can go on the train on the ceiling. (if our flatcar is carrying payload A, then only payload B can go on the one on the ceiling.)

Now, looking at the tiny bit I think I comprehended, what we've got here is a case where one of those four payload atoms has been replaced by an atom which is almost identical, but not quite.

This doesn't sound all that revolutionary, to me. Expressed the way I expressed it, it seems almost a case of "we were out of parts, so we used a substitute". Or "well, this patr kind of fits."

But then, the "mistake", if that's what you think of it as, bred true, and occurred in more than one place.

To me, it's one thing if they found one place where the expected atom has been "substituted by a generic equivalent". It's another matter when all of them have been.

I mean, does this lend support to the long-held theory that DNA "evolved" before larger structures did?

Maybe this "arsenic DNA" evolved first, and Carbon replaced Arsenic because Carbon was both more prevalent and more reactive?

Or am I asking for all kinds of conclusions that just aren't there?

[PeterMP]

Now, for those of us who need things explained to us . . .

Can anybody explain why this is important?

I mean, based on the tiny portion of High School biology that I still retain, my knowledge of DNA is that it's this big, huge, molecule, and that there's this one place on that molecule where one of four atoms can go. The big, huge, "base" or "carrier" part of the molecule can attach to two other bases.

Maybe an analogy would be to think of a railroad flatcar. The flatcar is huge, and complicated, and can attach to two other flatcars. (Any two flatcars.) One at each end.

The flatcar can carry one atom, from a menu of four choices. (I memorized what the four choices were, for a test. And immediately forgot them.)

There's a second string of flatcars, parallel to the first. (Imagine them suspended from the ceiling.) However, for each "payload" on the train on the floor, there is one and only one payload that can go on the train on the ceiling. (if our flatcar is carrying payload A, then only payload B can go on the one on the ceiling.)

Now, looking at the tiny bit I think I comprehended, what we've got here is a case where one of those four payload atoms has been replaced by an atom which is almost identical, but not quite.

This doesn't sound all that revolutionary, to me. Expressed the way I expressed it, it seems almost a case of "we were out of parts, so we used a substitute". Or "well, this patr kind of fits."

But then, the "mistake", if that's what you think of it as, bred true, and occurred in more than one place.

To me, it's one thing if they found one place where the expected atom has been "substituted by a generic equivalent". It's another matter when all of them have been.

I mean, does this lend support to the long-held theory that DNA "evolved" before larger structures did?

Maybe this "arsenic DNA" evolved first, and Carbon replaced Arsenic because Carbon was both more prevalent and more reactive?

Or am I asking for all kinds of conclusions that just aren't there?

Larry, I've made several comments in the other thread now.

It isn't As for C, but As for P, and potentially only when you starve for P. As and P are chemically very similar. As is bigger and "softer" than P, but in terms of making bonds very similar.

Can we get a merge?

[Larry]

Larry, I've made several comments in the other thread now.

It isn't As for C, but As for P, and potentially only when you starve for P. As and P are chemically very similar. As is bigger and "softer" than P, but in terms of making bonds very similar.

Can we get a merge?

You've explained the chemistry. (In, frankly, more detail than I can follow.)

That's why I was asking "But what does it mean?"

(And yes, I wholeheartedly agree with requesting a merge.)

[mardi gras skin]

I don't think I've been this disappointed since the Segway.

[HailYeah]

Thanks for the explanation Peter.

I'm with Vilandil in that I would be very interested to know how old this type of bacteria is. But as you pointed out on the other thread, there's no reason to think it is that old or has developed for very long on a separate evolutiounary path.

[PeterMP]

You've explained the chemistry. (In, frankly, more detail than I can follow.)

That's why I was asking "But what does it mean?"

(And yes, I wholeheartedly agree with requesting a merge.)

It means some organism has found away to not get killed by As in a manner that isn't solely dependent upon keeping As out of the cell (which is a common, but very uninteresting way of keeping anything from being toxic), and many of its "normal" (non-As affected that enzymes (which is many of them, even in us) that aren't involved in whatever it is doing to protect itself from As) enzymes are sloppy enough that they don't differentiate between the very chemically similar As and P very well and so it ends up with As instead of P in various biological molecules.

Of course, this might be true for "normal" enzymes in many organisms.

Enzymes are biological molecules that cause (i.e. catalyze) chemical reactions. They show specificity in terms of the reactions they cause to go, but they can be "tricked" and be "sloppy" when given conditions and molecules that aren't biologically/evolutionarily relevant.

[RVAbrendan]

I don't think I've been this disappointed since the Segway.

[Larry]

Enzymes are biological molecules that cause (i.e. catalyze) chemical reactions. They show specificity in terms of the reactions they cause to go, but they can be "tricked" and be "sloppy" when given conditions and molecules that aren't biologically/evolutionarily relevant.

Unskilled labor?