Alien life form ‘is here on Earth’ | Hacker News Reader

Alien life form ‘is here on Earth’

skymania.com

99 pointsalexandros66 comments

This article is totally speculation. They don't even know what NASA's announcement is. This reminds me of the speculation about Apple's announcement, and the resulting disappointment when it turned out to be just an announcement that the Beatles were now on iTunes.

I'm going to pass on the speculation and wait for the real announcement from NASA.

It's fun to speculate. Most people talk about sports stats or politics. We speculate about NASA announcements.

And NASA could learn a thing or two about branding from Apple. Space needs to be cool again.

This is what happens when you try your best to build suspense. It was Apple that announced "tomorrow is a day you will never forget". If NASA is playing the same trick, shame on them.

Especially if NASA suddenly starts selling The Beatles.

Now, if they discovered an arsenic-eating, microbial alien life form which could play Beatles tunes, that would be a day I'd never forget. The day the universe jumped the shark.

ironically, i might not because the hyperbole was so great; i'll always remember it as the canonical example of an over-hyped announcement.

seems like a great guess to me: http://en.wikipedia.org/wiki/Felisa_Wolfe-Simon

It should be pointed out that there's a fairly vast range of metabolisms already known for bacteria. The test of whether life developed twice will be how whatever-it-is stores its genome (DNA?) and how it goes about making useful molecules (proteins, etc). All currently known life does this in roughly the same way. *

* (discounting viruses, which are oddities that probably arose from cellular life)

> * (discounting viruses, which are oddities that probably arose from cellular life)

This is a general post, not intended at you specifically, but you imply that viruses are living, so I feel the need to throw this out there: I think the key reason the exception has to be made for viruses here is that viruses simply aren't alive. They have no biological processes, they don't reproduce, don't eat, don't breathe, don't create or consume energy, etc. A virus is really nothing more than a piece of data in a container. One of the traditional arguments is that they do reproduce, they just do it via a living cell, but to that I say: does a CD reproduce when a human copies it?

I think that in a couple decades, we'll look back on viruses being defined as living organisms and wonder what we were thinking.

You seem to think the definition of life is going to get sharper in the future. I'd say all signs point towards it getting a lot fuzzier instead; what will die is the idea that it is a binary yes/no instead of yet another continuum. Is a sufficiently advanced AI alive? Well, some yes, some no.

Actually, I don't think it'll get much sharper, if at all, largely for the reason you mentioned. I think that what we consider to be "alive" will largely grow more fuzzy, but what isn't alive will be sharper. I don't find it hard to believe that a computer running advanced software (e.g. an advanced AI) is alive, but I find the idea that a piece of inert data (a virus) is alive to be counterintuitive and wrong.

  > I say: does a CD reproduce when a human copies it?

If CDs somehow found their way to my burner and caused themselves to be copied, I'd be inclined to say yes.

Viruses don't "find their way" into cells, though. Cells stumble upon them, take them in, and are then infected. In this way, it's like you plugging a USB thumbdrive into your computer, and becoming infected.

It's really too bad that brownian motion doesn't work at the macroscale, then. :)

The music "ecosystem" undergoes artificial selection by humans. By definition, there will exist more copies (legitimately manufactured or burned at home) of more popular albums. This is similar to the concept of a meme. (By the way, it would make more sense to ponder whether the information reproduces itself, rather than the physical disc.)

No one would say the albums reproduce themselves, but then again no one is saying the biological reproduction so crucial to natural selection requires the organism to deliberately reproduce or even be aware of the reproduction.

All living organisms require something external to survive and reproduce—in the case of viruses, the requirement may be another living cell. The reproduction argument is insufficient to declare viruses non-living. I don't think biologists are trying to pass judgement on viruses, rather I believe the definition of life is less important to them than, say, the cell. Viruses aren't cells, and I think that's why textbooks waste time on the "are viruses living" debate.

I mis-spoke; it wasn't my intention to call viruses alive. My intention was actually the opposite: I was trying to anticipate a possible objection to what I said about all known life having the same genome type (double stranded DNA). That's true as long as one discounts viruses as a sort of life.

Really though, whether one wants to call viruses alive or not is a philosophical point, detached from any real significance.

Who has defined viruses as living organisms? Biologists don't.

Ah, then what about prions?

I don't know much at all about prions, so take this with a large grain of salt, but it seems to me that most -- if not all -- of the arguments against viruses being living organisms apply to prions. In the case of prions, the data is just in the form of a malformed protein, rather than a snippet of RNA or DNA. There may be something about them that I don't know that negates one or more of those arguments, though.

There's nothing here that really shows that "life began not just once but at least twice on Earth." Just because they have different metabolism (even dramatically different) it doesn't exclude the possibility that life began once and then branched (via evolution) into these two groups that derive their energy from different elements. After all, sulfur-reducing bacteria (which use sulfur instead of oxygen) are well-known and nobody suggests independent origins for them.

Being pedantic here...

  (via evolution)

Evolution is not a process, it is an effect. Evolution does not cause things to happen. Genetic mutation is the reason life evolved.

Just had to say that.

It's not a cause, sure. But I have never heard the word evolution defined to not apply to the process. Do you have a better reference I could read?

That makes me wonder if there are any "you can't get there from here"s in biology.. metabolic bases that are so different that they could not have been progenitors of each other through evolution. I suppose the answer is probabilistic.

Well, as gort pointed out, if they adhere to the central dogma (DNA > RNA > Protein) then the answer is 'probably not' (i.e. you can get everywhere from there). However, if they used an entirely different type of chemistry to make life then I think it would be likely that they evolved separately.

This is what "intelligent design" proponents are trying to prove all the time, isn't it?

True, but if found a striking example of "you can't get there from here" would marginalize their efforts.

Doesn't it depend on just how different these organisms are? If, for example, they have nothing resembling the cell of a prokaryotic or eukaryotic organisms (DNA, etc.), it can definitely mean something big. If they have the same "conceptual" cell but the details of its internals differ somewhat, then indeed it's far from scandalous, it just means the evolutionary tree branched earlier than with other organisms.

The second case would also be interesting in itself, of course.

Evolutionary processes aren't magic, they can only move along gradients defined by small changes. If it can be shown that these bacteria have something so radically different that it couldn't possibly have gotten there by small changes, such as by having a biology with no resemblance to DNA/RNA as we know it, then I'll have to accept a second origin.

However, if these things were just discovered I find it unlikely these have been analyzed to the point that we can be conclusive about it. Historically speaking people have tended to get radically more excited about this sort of thing than they have scientific justification for, for a variety of reasons. The full answer will probably take longer, unless they've been successfully sitting on this for a rather long time. A slow process of swapping in arsenic for phosphorus might cover it and leave something superficially distinct from modern life but still clearly descended from it.

bit of a misleading title - potentially arsenic-metabolising lifeforms aren't "alien" to earth. "It means that life began not just once but at least twice on Earth." Still exciting, but less so than potential ET's (e.g. meteors carrying lifeforms to earth, http://en.wikipedia.org/wiki/Red_rain_in_Kerala)

I know. Figured changing the title would put me in a worse position than just keeping it as it is. Perhaps a moderator can change it to something more appropriate.

If life began twice on Earth, it almost surely developed somewhere else.

If this story turns out to be true my first questions would be:

1) Do the arsenic-feeding microbes have DNA/RNA or some other system in place?

2) Do they appear to be subject to natural selection?

3) Have they spent this entire time in the lake?

"2) Do they appear to be subject to natural selection?"

why would they not be subject to natural selection?

I guess I might have phrased the question differently. I recently saw a video somewhere of Richard Dawkins talking about what he thinks of the possibility of extraterrestrial life, and among other things he was talking about his high degree of certainty that whatever life may exist on other planets, it's likely to be subject to the same forces of natural selection as exist for life here on Earth. It would be very nice to have a second example to suggest, "wherever life happens, evolution as-we-know-it happens".

If there's imperfect replication and death, natural selection happens. It's a mathematical fact; observation is unnecessary for confirmation.

Although I haven't seen the video, and Dawkins is a smart guy, so perhaps he was making some related point.

This comment seems wrong to me. What if Einstein had said, "sorry, General Relativity is a mathematical fact; observation is unnecessary for confirmation" instead of proposing tests!

Edit: Also, I think it would be just plain cool to observe natural selection in life that arose completely independently of our own. I don't think any reasonable person seriously doubts that natural selection is necessary for life.

Funny thing is, Einstein did in fact pretty much said it:

http://en.wikipedia.org/wiki/Tests_of_general_relativity#Def...

"When asked by his assistant what his reaction would have been if general relativity had not been confirmed by Eddington and Dyson in 1919, Einstein famously made the quip: "Then I would feel sorry for the dear Lord. The theory is correct anyway.""

Not only that but it would be interesting to see natural selection processes evolving using something other than what's familiar to us (DNA). If something like this were truly separate from us, wouldn't it have evolved its own genetic system (or equivalent) as well?

Some bacteria and viri use RNA. But I guess that doesn't really count as being different enough from DNA.

I think he was predicting/speculating that any complex life anywhere will have arisen through Darwinian selection; that there's no other process that leads from simple replicators to complex life.

Video is here: http://www.youtube.com/watch?v=vueDC69jRjE

Jump to 1:20.

That's already two quite big assumptions. There might be other means of mutation than imperfect copying or no mutation at all. I also wouldn't rule out that there couldn't exist a ecosystem with no involuntary death. Space is a big and weird place.

Evolution isn't some process that's specific to life. It's just a term we use to describe what happens to a living system with external pressures.

That same process happens to any system with external pressures. If I put a bucket in the rain, rain will collect in it. Someone coming along might exclaim, "See how perfectly that water has shaped itself to fit exactly into that bucket!"

Unless it's a leggy brunette with green skin, I don't wanna hear about it.

OT, but did anyone else feel surprise and nerdjoy to read that this actually exists on Earth:

a deadly poisonous lake... Mono Lake, in California’s Yosemite National Park... one of the highest natural concentrations of arsenic

I thought forbidden lakes whose inky waters are death to mortals were the stuff of fantasy novels. (In fact, any Terry Brooks fans think this was the inspiration for the Hadeshorn?)

(After a bit of further reading, it seems the article overplayed the "deadly" aspect, since fish live in the lake, birds eat there, and humans have dived in it: http://en.wikipedia.org/wiki/Mono_lake)

The Berkeley Pit (http://en.wikipedia.org/wiki/Berkeley_Pit) is similarly fantasy-novel in its toxicity. Indeed, it is the result of the works of men, inadvertently poisoning the land in their search for buried riches.

It dissolves the geese that land on it, but they still found life in it not too long ago.

This was the subject of a Radiolab segment not too long ago: http://www.radiolab.org/2010/jun/28/even-the-worst-laid-plan...

I have to post links to Radiolab whenever something related comes up on HN because I am so sure that many HN readers would love Radiolab, and I am afraid there are still people out there who haven't discovered it.

+1 for "dissolves the geese".

That's an exaggeration, but it is extremely hostile.

Goose goo

  whose inky waters are death to mortals

And yet you can swim in the lake. Snorkeling there is supposed to be quite the experience.

If you want a really scary lake, try Lake Karachay:

  According to a report by the Washington, D.C.-based
  Worldwatch Institute on nuclear waste, Karachay is 
  the most polluted spot on Earth.

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

Also: http://www.damninteresting.com/in-soviet-russia-lake-contami...

I was surprised to learn that Mono Lake, [is] in California’s Yosemite National Park. Last time I checked, it was well to the east...

and the article also called it "Mona Lake." Their facts aren't straight.

Well, this would certainly fit the pattern of NASA's previous "big announcements". Everybody speculates and guesses, says it's little green men, but in the end it's just an interesting discovery which technically relates to their teaser announcement.

They tell us they've discovered something regarding extraterrestrial life. Then it turns out they mean "We found bacteria that like arsenic, here on Earth". Sure, we see where you're going, but in the end everyone is going to hate you, NASA, for making a huge fuss and then hitting us with a biological whimper, not an extraterrestrial bang.

Living organisms that aren't based on something resembling DNA/RNA would be just as big a deal as extraterrestrial life, and I don't think the labeling of such organisms as 'alien' is misdirection.

Now, if it proves that they're merely DNA/RNA based organisms that happen to metabolize arsenic, that would be a biological whimper, as yes, they're just an earlier branch in the evolutionary tree.

However something that appears not to share a common ancestor with the rest of life on the planet would be a huge deal.

"Phosphorus is a key element in all known forms of life. Inorganic phosphorus in the form of the phosphate PO43– plays a major role in biological molecules such as DNA and RNA where it forms part of the structural framework of these molecules. Living cells also use phosphate to transport cellular energy in the form of adenosine triphosphate (ATP). Nearly every cellular process that uses energy obtains it in the form of ATP. ATP is also important for phosphorylation, a key regulatory event in cells. Phospholipids are the main structural components of all cellular membranes. Calcium phosphate salts assist in stiffening bones."

http://en.wikipedia.org/wiki/Phosphorus#Biological_role

Is it scientifically possible that life does not exist on other worlds? This is a serious question. Billions of galaxies, each with billions of stars...it would be mind boggling to me that it would be possible that we are the only planet in the universe with life. Has anyone studied the possibility -- a sort of reverse Drakes equation (for life in general) -- that we could be the only planet with life?

Of course it's possible. We might be on the only planet in the entire universe that had the right combination of chance events and conditions for life to arise.

It's generally considered unlikely, but it's possible up until the instant we prove that there's life on another planet.

How about 1 - chance_of_life_on_other_worlds?

Some biologists have made a case for DNA replication evolving twice, independently:

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC148579/pdf/27338...

Apparently you can also make a case for the evolution of DNA itself, possibly from a 2-letter alphabet:

http://arxiv.org/abs/0710.0445

I think he's probably on target. This was my prediction in the previous thread on the upcoming press conference: http://news.ycombinator.org/item?id=1952449

As long as we're speculating wildly, let's pretend that NASA is announcing that they've found a crashed alien spacecraft chock full of new technologies.

So, who wants a hover car?!

Since we're in the realm of speculation, perhaps NASA found working (alien) nanobots that are somehow programmed not to turn Earth into grey goo.

Or maybe the found a portal into another dimension containing giant tentacles floating in the sky.

Again?

This article title is missing a question mark.

This article belongs on Digg, not HN.

Reading this article was like watching a 2-hour special on the Discovery Channel about a new discovery that turned out to be a mistake

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