[Edit] They are calling it a member of the Halomonadaceae, which means it is descended from the common ancestor of that group, and so does not represent a second, independant origin of life.
The scientists that made the discovery work for NASA.
Edit: That is to say, the work that led to this discovery was funded by NASA, and was done to gain information about how to look for life on other planets.
Phosphorous is used by all previously known life in a number of ways, including as part of the DNA backbone. If there's something that uses something else, it's a big deal.
It's a proof-of-concept for radical new ideas of where/how life can form.
For instance, Titan has a thick atmosphere and lakes of liquid ethane/methane. If Arsenic-based life exists, could there be Methane-based life in those depths?
Right, I guess 'methane-based life' was poor wording. Suffice it to say that this discovery implies that life can form in ways and places that we've never considered.
From everything I have read so far, it seems that this is not so much a case of life evolving separately, but rather a simple, albeit unique, case of natural selection.
If a bacteria could evolve to tolerate arsenic, it could then use arsenic as a substitute for phosphorus. That appears to be the case with the Mono Lake species.
Yes, it opens up the possible chemical signatures for life to be found elsewhere, but I would hardly call it "alien life".
Depends on how you define "alien", right? Alien as in different from human, then this qualifies. Alien as in extraterrestrial (ie. not originating on Earth), then this doesn't.
The bigger question, in my mind, is can you evolve a sentient species (in a few million years) from this microbe? And what would happen if we threw this microbe on Mars or Venus? Would natural selection allow it to thrive there?
If this is true, life evolving twice right here would have implications for what we would plug into the Drake equation, and make the deafening silence so far even a bit more eerie.
edit: It sounded like a separate evolutionary path initially before the actual announcement--that is what I was saying "if this is true" about.
That's the Great Filter, right there. Something which goes around killing off technological species, or something inherent to their development which prevents them from causing lasting change in the universe.
Of course. As there are in any other speculation about finding live ETs. We don't have a good model.
By analogy, if you could drop a modern human explorer on Earth at a uniformly selected random time in its history up 'till now, at a random spot it would almost always be uninhabitable.
Or less detectable life-forms. I.e. we're wired to ascribe intelligence to human-like intelligence. Something radically different or developed might not look like intelligence to us.
E.g. Are those proto-stars in a nebula? Or is that some transcendent intelligence's weekend project or substrate or waste matter?
My understanding: that is what makes the silence deafening. If it's probable that the universe is filled with other intelligent life, and we see no evidence of it, that means that these civilizations are all ending before they can get radio or long range space flight. Or shortly after.
I might be underestimating the sensitivity of our instruments, but if we're just now being able to detect planets based on their gravitional signatures on stars, how can we be sure we haven't peered through a telescope at intelligent life already? Our species was pretty damn interesting 300 years ago, but if the aliens were looking for was radio signals we didn't "exist" to them until about 1920. And our radio waves haven't even gone that far yet, 100 light years is nowhere. Maybe in a 1,000 years when they get somewhere and aliens notice, they'll dispatch their ship and another 1,000 years later land here.
I wouldn't expect to get found in the woods a millisecond after I lit the signal fire, and thats where we are today in universe terms.
That's where we are--but the universe is 14 billion years old, and there are many, many planets out there much older than ours; some several times older. It should only take a few millenia for any truly successful life in our galaxy to colonize the whole thing: less than a cosmic eyeblink.
Yea but that point, you are getting around faster than the speed of light. If you can move faster than the speed of light, why would you use radio waves for anything? What if their entire communication/transportation happens in some manner we can't comprehend.
Imagine trying to show an iPad videochatting someone else to Da Vinci. It would be black magic with so many layers of technology that he couldn't comprehend - and he was a smart guy. So in a few hundred years we've blown everything we thought we knew away. Who knows what physics and technology we will have in a few thousand years?
It took us millions of years to get all around the globe, when it "should" (in the same sense as above) only have taken a couple hundred. I don't think we should assume that life will necessarily take the most efficient path to any particular goal.
I'm not usually the type that debates this topic in forums and probably don't know what I'm talking about. However, my understanding is that the worry comes from not seeing artificial radio signals from other parts of the galaxy.
Look at a few numbers that we will assume to at least be in the ballpark, and roughly correspond with scientific consensus:
1. The Universe is assumed to be 13.7 billion years old.
2. Nothing can move faster than c, so light years are an
effective measure of the maximum distance anything can travel since its inception.
3. Our Sun is about 4.6 billion years old.
4. The universe is 13.7 billion light-years across.
Now, from these, I'm going to make a few propositions, given the lack of obvious extraterrestrial intelligence:
1. Stars stable enough to create life didn't appear until fairly late in the game, around the 9 billion year mark.
2. 5 billion years is a better-than-average time for a star system to stabilize and evolve life.
3. Stars stable enough to create life are still fairly sparse, as life in this universe is still fairly young.
4. Assuming 7 billion years as a bare minimum for the starting point for this process, and assuming the Earth is fairly quick, a reasonable upper bound for the distance that a civilization must be from us to have contacted us is 2 billion light-years.
Of course, there are a lot of variables here, and it's highly probable that maximum reasonable speed for a life-form to travel is as low as .1c, which means that even a civilization that sprung into existence at 6 billion years (assuming a star system stabilized very early in the game and then also evolved life in the better-than-average time of 5 billion years) would only be able to travel 1 billion light years, cutting off a fair amount of the universe from contact.
While the numbers involved in the time since the big bang are large, the distances a hypothetical civilization would have to travel are probably larger, especially given that evolving life, in our solar system's case, took well over a third of the time since the big bang, and that's not counting the circumstances that brought about the formation of our solar system, which took the remaining 2/3rds.
that's a lonely way of looking at things; there's probably nothing quite like us. i've said before but should reiterate, we perceive and experience a tiny portion of what makes the universe alive.
It's not just that. Look at the life progress in our world. How long until we're trucking around the galaxy? Not long...
So given that, if life were on another project, well, we'd expect them to be trucking around the galaxy too by now. And they're not.
That leads to the reasonable conclusion that there are not aliens at the same level as us in this galaxy.
Note: For aliens to be at the same level as us and not trucking around, they would need to be hopelessly close to use in evolution. Given how much has happened in just the last 10K years, that seems extremely improbable.
Hmm, this was supposed to be a reply to another comment...
It's great that they leaked it, though. My 9th graders' science class is going to tune in live, thanks to the leak. Good opportunity to make science seem timely and relevant to kids.
Your point is well-taken. I was reacting to the early hype that suggested these bugs may have originated completely independently of other life on earth. If the organism evolved to use arsenic as a replacement for phosphate in a DNA-like chemical, I'm not sure if the independent origins hypothesis is really warranted. The Nature summary I saw today did not mention anything like that. The nature of hype I guess.
http://news.ycombinator.com/item?id=1962894 - go.com
http://news.ycombinator.com/item?id=1962893 - nytimes.com
http://news.ycombinator.com/item?id=1962846 - nature.com
http://news.ycombinator.com/item?id=1962696 - longislandpress.com
http://news.ycombinator.com/item?id=1962386 - gizmodo.com
http://news.ycombinator.com/item?id=1962200 - gizmodo.com
http://news.ycombinator.com/item?id=1962110 - google.com
http://news.ycombinator.com/item?id=1957823 - skymania.com
http://news.ycombinator.com/item?id=1953228 - kottke.org