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Life on Earth descended from interplanetary germs?

By Tatarigami in News
Sun May 13, 2001 at 11:26:17 AM EST
Tags: Science (all tags)
Science

A discovery.com article describes an Italian geologist's successful culturing of bacteria found inside a meteoric fragment believed to be around 4.5 billion years old.


Bruno D'Argenio, performing research for the Italian National Research Council, is the scientist responsible for the experiment, which involved reviving the bacteria, called 'cryms', or 'crystal microbes'.

<SPECULATION>
Although the article doesn't spell it out, I'm guessing these bacteria were preserved as spores -- in extreme conditions (particularly excessive dryness), some forms of bacteria are able to survive by toughening the membrane around the nucleus and allowing the cytoplasm of the cell to die. When conditions become favourable again, the bacterium regenerates the cytoplasm.
</SPECULATION>

The meteorite bacterium has been demonstrated to be capable of surviving temperatures in excess of 950 degrees Celsius and swabbing with alcohol, although antibiotics have been shown to kill it easily. Once revived, the bacteria were cloned, and samples extracted for DNA analysis. The genetic code is unlike any bacteria on Earth for which a genotype is available for comparision.

If these bugs truly originate from beyond Earth, then this discovery lends weight to the theory ("panspermia") that life on this planet is derived from earlier forms which existed prior to the Earth aggregating from nebular material billions of years ago.

However, some biologists have expressed skepticism, noting that the revived bacteria are very similar to terrestrial bugs. (I'm assuming they mean physical makeup, since the article has already made the claim that they are poles apart genetically.) It has been suggested that the samples may have been contaminated, and the culture grown may have been an ordinary Earth-bound bacterium. Others have shown interest but have reiterated the position adopted by the scientific community in response to claims of bacterial life in the well-known Martian meteorite: extraordinary claims require extraordinary proof.

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Life on Earth descended from interplanetary germs? | 46 comments (42 topical, 4 editorial, 0 hidden)
What is the bacteria descended from? (2.00 / 9) (#2)
by John Milton on Sat May 12, 2001 at 10:03:27 PM EST

I'm always forced to believe in some sort of intelligent design when I look at the universe. No one has been able to tell me what caused the big bang or what caused the thing that caused the big bang. Life itself is proof to me that some sort of higher intelligence is at work in the universe. The Jerry Springer show is proof to me that that higher intelligence is leaving us mostly to ourselves.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


Big Bang (3.66 / 3) (#3)
by Tatarigami on Sat May 12, 2001 at 10:12:35 PM EST

Actually, there are some pretty interesting theories on what caused the big bang:

http://www.kuro5hin.org/?op=displaystory&sid=2001/4/10/21145/1775

...but I'll have to go along with you in agreeing that we don't know much about the cause of the cause. To be completely honest, I hope I'm not there if we ever do learn the final ultimate answer to life, the universe and everything. What's left to look for after that?


[ Parent ]
Point here. You're elsewhere. (3.00 / 1) (#8)
by funwithmazers on Sat May 12, 2001 at 11:19:51 PM EST

The point is, you can't have a big bang without some kind of matter or energy. Where did this energy come from? Perhaps time is loop and the big bang is just a convient reference point. Perhaps there is a god. Who knows? I'd say Theory of Everything is like light speed, unattainable by human beings.

[ Parent ]
Yes you can (4.50 / 2) (#38)
by spiralx on Mon May 14, 2001 at 06:18:29 AM EST

The point is, you can't have a big bang without some kind of matter or energy.

Yes you can. The big bang wasn't like an explosion after all, there was no need to have energy available to blow some matter up and create a Universe...

Besides in one sense the Universe has a net total energy of zero, in that the gravitational potential energy of all of the matter in the Universe is negative and equal to the positive energy of the matter in the Universe. So given that something can appear spontaneously as a vacuum fluctuation and last for a period of time inversely proportional to its energy, it's quite possible for the Universe to have been created.

You're doomed, I'm doomed, we're all doomed for ice cream. - Bob Aboey
[ Parent ]

Yeah, I saw that. (3.00 / 1) (#9)
by John Milton on Sat May 12, 2001 at 11:53:10 PM EST

I saw that story on The Other Site before I gave up on It for good. I nearly laughed out loud when I read it. To explain the one universe we have, physicist theorize another one that triggers our big bang. Great way to explain something. I realize I may sound ignorant from my post above, but I'm actually pretty knowledgable in physics. It has been one of my hobby subjects since the age of twelve.

I'm getting really sick of hearing about the theory of everything. I think it is sheer arrogance to think that we are even close to having the complete theory of everything. Arrogance of that level just ticks me off. Aristotle thought he had it all figured out too.

P.S.: I hope we don't find out the ultimate answer for a long time too. It would ruin the fun of finding it.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
Logic quibbles (5.00 / 8) (#5)
by brion on Sat May 12, 2001 at 10:22:44 PM EST

I'm always forced to believe in some sort of intelligent design when I look at the universe. No one has been able to tell me what caused the big bang or what caused the thing that caused the big bang.

This line of reasoning can be used just as effectively against the idea of intelligent design of the universe - if there was a creator, who or what created the creator? 'It/they/he/she created it/them/him/herself' or 'it/they/he/she just always existed' is just as bad, or good, an answer as 'well, the big bang just WAS, nothing caused it'. This doesn't necessarily rule out the possibility of intelligent design, but it's no better an explanation on this criterion than the conventional physics theories.

For more along this theme, you might check out the first chapter or two of The Blind Watchmaker : Why the Evidence of Evolution Reveals a Universe Without Design by Richard Dawkins. I think I read it for a biology class back in high school; most of the book deals with biology and interesting quirks of evolution that don't make much sense except from the viewpoint of natural selection.



Chu vi parolas Vikipedion?
[ Parent ]
No sense quibbling (4.50 / 2) (#6)
by John Milton on Sat May 12, 2001 at 10:39:00 PM EST

Yes, I know this is an argument that has been batted back and forth for centuries. I don't expect to come up with the undefeatable arguments now. I just feel that the universe was created. The Hebrew word Yawweh can be interpreted as "the self existing one." This is pretty much how I feel about God. I may not know all the answers, but I'm willing to take a leap of faith. I'd rather take a leap of faith on an intelligent creator than blind chance.

The universe to me screams of intelligent creation. You mentioned watchmakers. If you find a watch on the sidewalk and look at all of it's intricate gears moving in step with each other, would you believe it fell together by chance over millions of years or would you believe that someone you hadn't seen put it together.

When they found the heads Easter Island, they knew right away that they were designed by intelligence. Would anyone make the claim that millions of years of erosions would cause those heads to form. Perhaps once, but over and over again? If the bonding angle of H2O was one hundred billionth of an inch shorter or longer, life would not exist.

Life to me is a miracle. I'm not saying all of evolution is wrong, but I feel that it is a bit overhyped. The fact that is true doesn't destroy my faith in higher intelligence.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
Not exactly about bacteria, but... (5.00 / 2) (#12)
by brion on Sun May 13, 2001 at 01:48:32 AM EST

Yes, I know this is an argument that has been batted back and forth for centuries.

Yes, and I don't expect we'll be solving it on K5 anytime soon. :) In any case, divine creation can neither be proved nor disproved short of the deity involved showing up and saying "Hi, I'm your Creator, here's all the evidence and proof you could want, feel free to run experiments on me, oh, and here's my detailed documentation on how I influenced the universe over the last few billion years." So, we remain in a state of ambiguity on the question...

I may not know all the answers, but I'm willing to take a leap of faith. I'd rather take a leap of faith on an intelligent creator than blind chance.

Personally, I've always felt that a self-created universe is more miraculous, more amazing, more beautiful than one shaped by a creator's will. If it came about by 'blind chance', then it's a wondrous thing, not something to be scorned at!

You mentioned watchmakers. If you find a watch on the sidewalk and look at all of it's intricate gears moving in step with each other, would you believe it fell together by chance over millions of years or would you believe that someone you hadn't seen put it together.

Dawkins makes an excellent rebuttal to this argument in his book - I seriously recommend you visit your local library and check it out. Even if you find it overly preachy, it's an interesting read, especially if random biological oddities amuse you. To summarize his argument briefly: look closer at the watch, you'll notice a lot of things about it that are inefficient, random, or even somewhat detrimental to its function, but that it works well enough as a timepiece - completely in sync with, say, a theory that random watch parts might fall together in a bin, and that you only see the ones that work well enough to pass quality assurance.

Or, to turn the watch thing on its head... if you see a watch lying on the sidewalk, do you assume that it was left there deliberately, carefully placed so that you would find it - or that somebody dropped it by accident?

When they found the heads Easter Island, they knew right away that they were designed by intelligence.

The other big problem with the watch/watchmaker analogy... The explorers here would have had previous experience with statuary, knowing that statues are made by human beings. Thus, upon finding statuary, human beings were assumed to have made them. Ditto with the watch - we know that watches are made by people, so we automatically will assume a creator when we find another watch and start from there. If you've never seen such a thing, you might not know what to think.

If the bonding angle of H2O was one hundred billionth of an inch shorter or longer, life would not exist.

Yes - amazing to think that this tiny molecule works exactly that way! But... when you think about it, it must work that way. Any universe in which water did not work in this way could not support life, and thus wouldn't contain people to ponder that fact. By definition, the universe we live in must support life, it is a 100% probability that we live in such a universe...

Life to me is a miracle.

Absolutely! We're in agreement there.

I'm not saying all of evolution is wrong, but I feel that it is a bit overhyped. The fact that is true doesn't destroy my faith in higher intelligence.

Intelligent behavior doesn't have to come from deliberate intelligence (if such a thing really exists). Natural selection is the classic example, overhyped or not - pretty good (but not perfect) beings come about by being the ones to reproduce and survive in their environment. My personal conception of "God" is the living universe: conscious/deliberate/personified or not, it exists and is pretty darned interesting.



Chu vi parolas Vikipedion?
[ Parent ]
I'd love to see that. (5.00 / 2) (#23)
by John Milton on Sun May 13, 2001 at 02:03:17 PM EST

Yes, and I don't expect we'll be solving it on K5 anytime soon.

I'd love to see the headlines for that one. K5 discovers the meaning of life. Of course, you remember what happened when they tried to discover the meaning of life in The Guide. The psychiatrists tried to have them killed. Put's all the philosophers and bs artists out of work.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
Wow (5.00 / 5) (#31)
by Tatarigami on Sun May 13, 2001 at 05:10:44 PM EST

Whatever your personal theory on the creation of the universe, I think we're witnessing a miracle right here and now: intelligent debate on a controversial topic with each side giving the other's reasoning the respect it deserves.

I hope Kuro5hin's archiving function doesn't suddenly break down, because no-one's going to believe this unless I can produce the evidence...


[ Parent ]
Life, the Universe, and Everything (4.75 / 4) (#30)
by swr on Sun May 13, 2001 at 04:38:44 PM EST

The universe to me screams of intelligent creation.

I suspect that is because you are intelligent. If you have a hammer, everything looks like a nail. If you have intelligence, everything looks like intelligent creation.

I, on the other hand, am perfectly confused. This allows me to see the answer to "where does it all come from?".

My answer is, "I don't know."

I challenge anyone to produce a more truthful answer.



[ Parent ]
Nice attitude (none / 0) (#32)
by John Milton on Sun May 13, 2001 at 07:44:02 PM EST

I think that you may have hit the nail on the head. No pun intended. The universe is something we should look at with awe.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
I think both intelligent design AND evolution. (5.00 / 1) (#7)
by rebelcool on Sat May 12, 2001 at 11:01:01 PM EST

Life (and in fact, the universe) is incredibly well put together. And while it's of course completly possible that such a thing could simply fall into place, and perhaps some things did, I dont think its all that way.

The way I see it, life on earth, was most likely created. As of today, we can clone and do pretty crude genetic manipulations. In a century or two, we should have no problems generating brand new life forms of our own. Designs of our own. I see it as completely feasible that another life form did this. And perhaps they themselves were designed by someone.

As for the universe, it's possible that someone could create it. A science experiment. An amazing one, to be sure.

As for evolution, it only makes sense to make life forms adaptable to their environment. Build it into the design. A good piece of software is flexible and can adapt to its environment. It's designed that way. Why should life be any different?

COG. Build your own community. Free, easy, powerful. Demo site
[ Parent ]

Natural selection (5.00 / 4) (#21)
by Eloquence on Sun May 13, 2001 at 10:24:48 AM EST

And while it's of course completly possible that such a thing could simply fall into place

What if this universe, with all its laws and conditions, is just one of an infinite number of universes? Quantum physics already allow the existence of parallel universes, so it seems safe to assume that the process which constitutes our universe is just one of many similar processes. The only universe where someone could observe the conditions under which it exists is one where these conditions would allow an observer. That we are here is not luck, it is merely logical, a result of natural selection not among people, but among universes.

The intelligent design theory, on the other hand, doesn't answer anything, it just makes it easier to ignore the question. Did the creator "simply fall into place"? You can apply the same logic as above to the universe the creator lives in, unless you assume the creator "has always existed, exists everywhere" etc., an assumption which you can also make for the multiverse. But if you assume the existence of an all-powerful, all-everything creator, there's another question that needs to be answered: Why create a universe if you know everything and are everything? What then is the creator? The "watchmaker creator" is an oxymoron. But the believer never questions his definitions, because the definitions need not be logical or consistent -- they just need to fit his emotions.
--
Copyright law is bad: infoAnarchy Pleasure is good: Origins of Violence
spread the word!
[ Parent ]

heh... (4.00 / 2) (#22)
by rebelcool on Sun May 13, 2001 at 01:13:58 PM EST

i wasnt asking about the creator. Rather, life on earth and this universe in general.

Now, where is the root of it all? We simply don't know. I think in that department anyone's guess is as good as anyone elses. For all I know, a mysterious galactic hotdog appeared out of nothing and then spawned every universe.

The question to the "lucky fall into place" people is the same as the intelligent design. How does something come from literally nothing? If there's nothing to seed the lucky event, how did it occur?

COG. Build your own community. Free, easy, powerful. Demo site
[ Parent ]

You have to put faith in something (4.66 / 3) (#27)
by John Milton on Sun May 13, 2001 at 02:25:00 PM EST

But the believer never questions his definitions, because the definitions need not be logical or consistent -- they just need to fit his emotions.

Just as the scientist puts faith in a logical explanation. The arguments against an intelligent creator are the same ones against sheer chance. If I have to choose between an intelligent hand forging the galaxies and myself or sitting theorizing about the meta-universe that created this universe and where the meta-universe came from, I choose intelligent creator. No matter what scientist like to say, this matter will never be solved by reason. Some people may arrive at their faith by reason, but that isn't the same thing. I'll take what I find pleasing.

I realize you may have not meant for this post to be insulting, but it was. Before you call believers simply emotional, please consider how ridiculous any theory of the universe is. We are but poor players, strutting and fretting our our upon the stage.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
Rediculous? (5.00 / 2) (#37)
by spiralx on Mon May 14, 2001 at 06:13:41 AM EST

The arguments against an intelligent creator are the same ones against sheer chance.

Sheer chance plays a role in scientific theories such as evolution, sure, but it's not the be all and the end all, there's an organising factor to be considered as well - natural selection in evolution, gravitation in the formation of the Universe as we see it today.

No matter what scientist like to say, this matter will never be solved by reason.

That's very much an article of faith :) Our knowledge is too limited for us to know even how much we can know...

Before you call believers simply emotional, please consider how ridiculous any theory of the universe is.

I object to this, because it's not true if you understand how and why these theories come about. Quantum mechanics seems to be incredibly arbitrary and strange, but when you understand it a bit better it makes perfect sense and is based upon firm evidence. Cosmological theories are obviously less firm due to lack of direct evidence, but they aren't just pulled out of thin air.

You're doomed, I'm doomed, we're all doomed for ice cream. - Bob Aboey
[ Parent ]

simply put (3.00 / 4) (#14)
by xriso on Sun May 13, 2001 at 03:32:46 AM EST

Well, the universe has a beginning. It didn't cause itself to exist, because it wasn't there to cause it. Therefore the universe has an external cause.
God does not have a beginning, therefore he is not necessarily subject to an external cause.

I suggest a visiting of reasons.org. Reasons to Believe takes the view that the universe is 17 billion years old (and very very fine-tuned to allow for life, even complex chemical structures), but that this is not nearly enough time for any complex evolution to occur, hence there is an intelligent creator.
--
*** Quits: xriso:#kuro5hin (Forever)
[ Parent ]

The Universe (3.66 / 3) (#17)
by Anonymous 6522 on Sun May 13, 2001 at 04:23:43 AM EST

Nothing is external to the universe, the universe is everything.

Yes, the universe as we know it seems to have had a beginning, but that doesn't mean it wasn't there before that "beginning" in a different from, or that the universe, of which the known universe is a part, had a beginning.

[ Parent ]

You are finite, Zathrus is finite, this wrong tool (4.25 / 4) (#20)
by brion on Sun May 13, 2001 at 05:15:23 AM EST

Well, the universe has a beginning. It didn't cause itself to exist, because it wasn't there to cause it.

The thing that always gets me here is that time, like space, exists inside and of the universe. So the concept of something happening before the universe existed is meaningless. Or... something. Ow, my brain hurts...

I suggest a visiting of reasons.org.

I'm rooting around it now... Just found the probability estimate for attaining the necessary parameters for a life supporting planet. It's unclear how these 123 factors were chosen, how their probabilities were calculated, or how the aggregate probability is supposed to mean anything at all. It feels like calculating the odds of one particular dust particle anywhere on the earth falling into my bedroom, and using that small probability to prove that there cannot be dust in my bedroom unless someone came in and deliberately put it there.

Frankly, I'm disappointed. If I'd wanted poor reasoning about interesting ideas, I'd go to atlan.org and read about how all of modern civilization is derived from expatriots of sunken Atlantis, which according to them "sunk" into the South China sea due to rising water levels at the end of the last ice age, about 11,000 years ago.



Chu vi parolas Vikipedion?
[ Parent ]
Ah Atlantis (4.50 / 2) (#25)
by John Milton on Sun May 13, 2001 at 02:15:18 PM EST

The myth of Atlantis was taken from a story Plato told of an island that sank in the sea on one day. Plato himself said that it was merely a allegory, but that doesn't stop some people. I have to admit it's appealing. I love reading those interesting ideas myself. Sometimes there is nothing more fun than imaginary archaeology. Indiana Jones proves that.


"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
The story may not even have originated with Plato. (4.00 / 1) (#34)
by Wayfarer on Mon May 14, 2001 at 12:09:32 AM EST

The Atlantis story as told by Plato is allegedly secondhand according to some accounts, attributed to the reports of one Solon, a respected statesman, if I recall correctly.

Goes to show that even Plato appreciated the value of a good story. ^_^


-W-

"Is it all journey, or is there landfall?"
-Ellison & van Vogt, "The Human Operators"


[ Parent ]
Allegedly from Egypt (4.00 / 1) (#35)
by brion on Mon May 14, 2001 at 01:43:44 AM EST

Now, it's been a while and I've only briefly glanced at the relevent portions of Plato, so I could be wrong in some details, but my recollection of the affair is such:

The guy whose words are related by Plato (named something like Timeus or Kriteus... I forget which, sorry) tells the tale as told to him by his old teacher, the earlier Greek historian Solon. Solon had travelled to Egypt many years previous, and talked to the priests and historians there, who told him about Atlantis, and something about a war between the Atlantians and the ancestors of the Greeks... or something. I'm a little vague on it; if you want the details pull out Plato and flip through the chapters named for the guy.

In any case, it's thus at least fourth-hand by the time it got to Plato. So take it all with a grain of salt (preferably a big one).



Chu vi parolas Vikipedion?
[ Parent ]
We're getting off topic but... (none / 0) (#43)
by John Milton on Mon May 14, 2001 at 05:41:22 PM EST

I can't resist. Here's a link to some more information about Plato's role in the Atlantis story. Also here's the intro to the page:

The story of Atlantis begins in the mind of a famous ancient philosopher, Plato. Plato compiled the first written and perhaps the most detailed account of Atlantis. His two books which include passages concerning Atlantis are the Timeaus and the Critias. These books contain dialogues between the philosophers of Plato's time, and include references, spoken only by Plato, to Atlantis.

"When we consider that woman are treated as property, it is degrading to women that we should Treat our children as property to be disposed of as we see fit." -Elizabeth Cady Stanton


[ Parent ]
Which intelligent designer? (5.00 / 2) (#40)
by bediger on Mon May 14, 2001 at 10:54:03 AM EST

John Milton writes: I'm always forced to believe in some sort of intelligent design when I look at the universe.

Very interesting, John. Which Intelligent Designer do you see, because I see a whole lot of them. I see Apollo pulling the sun across the sky in his Flaming Chariot, I see Thor in the truly majestic thunderstorms that roll out of the mountains, and I see Loki in a lot of biology, particularly the human birth process. Only a trickster would put that bizarro, elaborate, error-prone and harrowing process in place, eh?

My point is this: the "intelligent design" theory is useless. It doesn't have predictive value, in that one can't really say *which* intelligent designer put which part of the universe in place, and one really has to question the intelligence of some or all of the "intelligent designers" because a lot of biological processes are just plain whack. Also a fair proportion of "intelligent" design appears to have been just plain evil, like tapeworms perhaps. You can fill in the blanks. And that's why I think "intelligent design" is a crap theory


-- I am Spartacus.
[ Parent ]
Logic of science (5.00 / 1) (#42)
by sigwinch on Mon May 14, 2001 at 04:45:42 PM EST

No one has been able to tell me what caused the big bang or what caused the thing that caused the big bang.
Of *course* not. A theory that purports to explain everything, using nothing but logic, is a tautology. It is just a system of consistent statements that refer to themselves. Meaningful theories of physics must incorporate at least one fact, one observation about the actual universe. At some point, the theoretical rubber must meet the physical road. In the case of big bang theories, these facts are several observations that are consistent with a singular cataclysmic event in the distant past.

And anyway, the big bang hypothesis does not contradict intelligent design. Or would you dictate to God that He cannot use a big bang as the instrument of His creation?

--
I don't want the world, I just want your half.
[ Parent ]

question... (2.40 / 5) (#10)
by univgeek on Sun May 13, 2001 at 12:36:59 AM EST

So why is there absolutely no sign of life on the moon or Mars or wherever else? If life can survive inside a meteorite for 4.5B years why couldnt we find anything in all the samples that everyone has taken?? And I dont want to hear someone start on a big conspiracy theory....
Arguing with an Electrical Engineer is liking wrestling with a pig in mud, after a while you realise the pig is enjoying it!
well... (4.80 / 5) (#11)
by TigerBaer on Sun May 13, 2001 at 01:04:22 AM EST

If i am interpreting the article correct, the bacteria was dormant on the meteorite. One could continue from this and speculate further that space-like conditions (vacum, extreme cold) would cause the dormant state. The moon has this state, therefore chances are any bacteria on the moon from asteroids.. meteorites. whatever.. is dormant.

As too why we havent found evidence of life.. we have only found maybe a handful of cases of possible space bacteria on the Earth. Mars and the Moon are much smaller, and we have only examined infitesimal portions of both the Moon and Mars. You cannot induce from the couple of pounds of material we gathered whether or not there is life on the Moon or Mars.

Arguing with a Computer Scientist is futile, because we are smarter >:)

[ Parent ]
Life on Mars (5.00 / 3) (#24)
by mbrubeck on Sun May 13, 2001 at 02:10:24 PM EST

"Absolutely no sign of life" is an overstatement. Actually, of the three life-detection experiments performed on Mars by the Viking landers, two were inconclusive and one returned a positive result.

At the time, NASA interpreted those results as a failure of the experiment. One reason for this was that the Vikings found an extremely hostile environment, which the NASA biologists believed could not support life. Thus they searched for other explanations for the experimental results, and found alternate possibilities that satisfied them.

But in the decades since then, Dr. Gil Levin - chief biologist of the experiment that returned positive results - has come to the conclusion that the Viking mission actually did detect life on Mars. His reasons include new knowledge about the ability of life on Earth to survive hostile Mars-like environments, and also the continued failure to experimentally demonstrate the alternate, inorganic mechanisms used to explain the positive results.

Many of Levin's papers and writings are online at the web site of Biospherics, his current company. Take them with a grain of salt - most exobiologists disagree with Dr. Levin, and will present their own evidence against his claims. But anyway, it is definitely still an interesting open question.

[ Parent ]

Added link (5.00 / 1) (#26)
by mbrubeck on Sun May 13, 2001 at 02:19:14 PM EST

Here's a link to Levin's 1997 paper that contains his main claims and arguments. Some of the links on the site are broken; it took me a couple tries to find this working one.

[ Parent ]
Sure the bacteria could be extraterrestrial... (3.66 / 3) (#16)
by Anonymous 6522 on Sun May 13, 2001 at 03:56:24 AM EST

...but that doesn't mean that life on earth evolved from them. If life on Earth did evolve from them, wouldn't their DNA have some similarities to modern bacteria? After all, we all would have to have evolved from them or their relatives.

Anyway, if life on Earth was seeded by extraterrestrial bacteria it would be that much more difficult to figure out how life came into being. It would have arisen in an evronment that we know nothing about.

Correct, but... (5.00 / 4) (#18)
by brion on Sun May 13, 2001 at 04:38:24 AM EST

If life on Earth did evolve from them, wouldn't their DNA have some similarities to modern bacteria?

That was my first thought as well, but I think the intent behind the statement was that it lends indirect evidence... If one example of extraterrestrial life exists, then others (possibly related) might as well. But really, as long as the bacteria aren't destroying a small town in Arizona by instantly coagulating peoples' blood, I just think it's neat.



Chu vi parolas Vikipedion?
[ Parent ]
From the linked article... (none / 0) (#19)
by Anonymous 6522 on Sun May 13, 2001 at 04:54:41 AM EST

May 10 - Italian researchers claim to have found conclusive evidence that life on Earth arrived from outer space
Scientist: "These alien bacteria are our ancestors!"

"Their genetic code is unlike any known on Earth," said Giovanni F. Bignami, scientific director of the Italian Space Agency.
Scientist: "They really are alien! Their genetic code is totally unlike ours!"

Me: "So how can they be our ancestors then?"

[ Parent ]

Flaw in reasoning (5.00 / 3) (#28)
by localroger on Sun May 13, 2001 at 02:29:34 PM EST

If life on Earth did evolve from them, wouldn't their DNA have some similarities to modern bacteria?

Not necessarily. Bacteria evolve rapidly when they are not dormant, and there is general agreement among scientists that just about everything on Earth is descended from a single very highly evolved protist. This single ancestor of all modern life may have lived as recently as 500 million years ago, and been the cause of the Cambrian Explosion; that leaves a lot of prior evolution which would have been eaten by these more competetive successors.

Modern cells have features which make them less tolerant to extreme environmental conditions and generally unable to crystallize and go dormant as the alleged space bacteria must have done. Yet these same characteristics make them more competetive in a benign environment like the Earth, and capable of assembling into cooperative masses, ultimately including multicellular organisms such as ourselves.

The alleged "space bacteria" would naturally reflect the state of bacterial evolution before all this activity took place. They might be very different from anything available for study now.

Ironically, the few examples we have of more primitive lifeforms which must have been dominant in the aeons before this evolutionary leap are now found only in places like volcanoes and deep ocean vents -- places where modern cells have a tough time surviving, so the "extremophiles" do not have to compete against them.

If this find is valid it is truly astonishing and important. I myself have traditionally found the panspermia theory needlessly complex, but this synergizes with some ideas (especially part of the "Rare Earth" theory) that the most likely places for biogenesis to occur might not in turn be the best places for the created life to thrive.

I can haz blog!
[ Parent ]

That raises an interesting question. (none / 0) (#33)
by Anonymous 6522 on Sun May 13, 2001 at 10:55:31 PM EST

If the bacteria could be totally different than us, and still be our ancestors, then that makes the uniqueness of their DNA much less compelling evidence. They could just be very very old earth bacteria that somehow found their way inside a meteorite, or a rock that looks suprisingly like a meteorite.

[ Parent ]
my question (3.33 / 3) (#29)
by Prophet themusicgod1 on Sun May 13, 2001 at 04:24:41 PM EST

as my accidental posting of this story is slowly being dragged into a bloody hell by the loyal K5ers...where is it that "life", or self replicating organisms first appeared then? obviously my relatives according to this article might have eventually came from space but...where did it all begin?
"I suspect the best way to deal with procrastination is to put off the procrastination itself until later. I've been meaning to try this, but haven't gotten around to it yet."swr
where? (none / 0) (#46)
by adrien on Tue May 15, 2001 at 03:58:29 AM EST

We have absolutely no clue exactly where, precisely when, and only a couple of vague guesses as to what - the first life on earth might have been.

My guess it would be pretty hard to track down the traces of some amino acids floating around a few billion years ago.

Thy why the space jism think is kindof interesting, at least there we might have a chance of finding a more precise answer (via a metiorite, finding unfertilized seeds on the moon, finding even remotely similar life forms elsewhere (I would say that if we found something with a DNA system even remotely simlar to ours, that we would share a common ancestor, but that's my opinion/guess)).

Of course, looking for an answer to a probably unsolvable detail of a question and jumping at the first opportunity that jumps along is Bad Science. You would be better of watching Mars Attacks.

I'n not an expert, if anyone knows different, speak up.


-adrien
[ Parent ]
DNA (5.00 / 2) (#36)
by adrien on Mon May 14, 2001 at 04:38:24 AM EST

"Their genetic code is unlike any known on Earth," said Giovanni F. Bignami, scientific director of the Italian Space Agency.

One might wonder: why the space alien DNA is so different if Life on Earth supposedly descended from similar specimens?

This could be explained by the fact that supposed "seeding" would have taken place billions of years ago. A lot can change in that time, which would suggest that if these samples were in complete isolation from the rest of earthling life, they could be relatively different.

On the other hand, critters from outer space probably have a biological makeup so different from what we have here on earth that they proaby wouldn't even have DNA, in any form similar to ours (that is, one that you could run a standard DNA analysis on and find out that the genome is "different").

Unless of course we shared an ancestor, which would of course support the panspermia theory, or the Invasion Of The Body Snatchers theory - whichever sells more popcorn.

If we were seeded by space jism, the original seeds would be wholly indistinct from life on earth - because they would be life on earth, unless of course a sample was somehow preserved, untainted since then, and the rest of the critters on earth changed enough to be distinctly different from the originals.

I would call it the 'time capsule' theory.

I am not a scientist. i'm just talkin'. If you disagree with me, you are probably correct.


-adrien
Since it hasn't yet been noted... (none / 0) (#39)
by Carik on Mon May 14, 2001 at 07:56:16 AM EST

I found the following an odd set of quotes:

"'Their genetic code is unlike any known on Earth,' said Giovanni F. Bignami, scientific director of the Italian Space Agency."

The Italian researchers have also identified microorganisms identical to the "cryms" found in the Naples meteorites in 50 samples of billion-year-old terrestrial rocks from five continents.

So, what we have here are space bacteria completely unlike anything on earth, except for these 50 samples that we've always assumed were from earth. Right....

Can they really say they're unlike anything known on earth if they've found things on earth that are identical to what they found in the meteorite?

-Carik

nitpick (none / 0) (#41)
by dutky on Mon May 14, 2001 at 10:57:13 AM EST

Tatarigami wrote:
<SPECULATION>
Although the article doesn't spell it out, I'm guessing these bacteria were preserved as spores -- in extreme conditions (particularly excessive dryness), some forms of bacteria are able to survive by toughening the membrane around the nucleus and allowing the cytoplasm of the cell to die. When conditions become favourable again, the bacterium regenerates the cytoplasm.
</SPECULATION>
pro-kar-y-ote
An organism of the kingdom Prokaryotae, constituting the bacteria and cyanobacteria, characterized by the absence of a nuclear membrane and by DNA that is not organized into chromosomes.

Koan for the day: What is the sound of a bacterium toughening its nuclear membrane?



Pro-karaoke (none / 0) (#44)
by Tatarigami on Mon May 14, 2001 at 06:16:14 PM EST

Okay, I admit I made an unwarranted supposition -- I was assuming the bacteria were eukaryotes.

eu-kar-y-ote
    A single-celled or multicellular organism whose cells contain a distinct membrane-bound nucleus.


[ Parent ]
Interesting evolution (none / 0) (#45)
by SIGFPE on Mon May 14, 2001 at 06:45:22 PM EST

When in contact with a physiological solution, they became visible and began to move
Hmmm...I wonder what selection pressures exist in space to result in organisms that move when they come into contact with a "physiological solution". Or maybe these organisms evolved on a planet that is covered in "physiological solution". Well what's the nearest planet that fits the bill? I think Earth is pretty close to where the meteorites were found. So even if these meteorites were proved beyond a shadow of a doubt to have landed on Earth with bacteria on them it seems logical to conclude that they in fact started off on Earth - maybe starting life as ejecta from a volcano or other dramatic event.

Given the evidence that is available and the conclusions that were drawn I find it hard not to draw the conclusion that these researchers are plainly lying (rather than mistaken) about the implications of their work. Given that they may be lying I'm not even sure I trust the basic experimental work that they have carried out either.
SIGFPE

Life on Earth descended from interplanetary germs? | 46 comments (42 topical, 4 editorial, 0 hidden)
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