DNA found in meteorites New insight into how life formed on earth

[Rajram]

http://lightyears.blogs.cnn.com/2011/08/11/dna-discovered-in-meteorites/

Just read this in CNN. Is it proof that life existed before earth and exists elsewhere in the universe? Life may not have evolved completely on planet earth after all. Could this DNA components have come from an old planetary system that existed along with the star that existed before sun that exploded into a supernova from which the solar system was formed? This is an interesting and exciting discovery indicating life is possibly spread all over the universe.

[Desi]

http://lightyears.blogs.cnn.com/2011/08/11/dna-discovered-in-meteorites/

Just read this in CNN. Is it proof that life existed before earth and exists elsewhere in the universe? Life may not have evolved completely on planet earth after all. Could this DNA components have come from an old planetary system that existed along with the star that existed before sun that exploded into a supernova from which the solar system was formed? This is an interesting and exciting discovery indicating life is possibly spread all over the universe.

That life existed before earth is without question in my mind and in minds of many. The universe has been teeming with life for billions of years. Whether life on earth evolved on its own or was seeded by life external to earth is not clear. Just finding of organic molecules in meteorites does not confirm that life on earth was started by those seeds rather than earth grown seeds. Earth had the right conditions for such molecule formation without being seeded externally and both could have happened.

The oldest of the known or available Meteorite with organic molecules is the Murchison Metorite. The theory that seeding of life on planets in the universe goes on with asteroids is called Panspermia. In addition to Murchison meteorite, an another meteorite supposedly a breakaway piece from Mars was found in Antartica with microscopic trails that looked like bacterial.

[boca]

Is it proof that life existed before earth[/quote]
No. It is another "evidence that (some) asteroids and comets (that we have observed) are comprised of the proper chemicals to generate the building blocks of life"

...and exists elsewhere in the universe?[/quote]
No. See above. The evidence of chemicals that are part of the building blocks of life isn't sufficient to conclude that "life exists elsewhere in the universe". Probable? Perhaps.

Life may not have evolved completely on planet earth after all.[/quote]
Possible. There are still gaps that begs explanation.

Could this DNA components have come from an old planetary system that existed along with the star that existed before sun that exploded into a supernova from which the solar system was formed?[/quote]
Will not be able to prove it easily. Don't know if supernova spares existing molecules.

This is an interesting and exciting discovery indicating life is possibly spread all over the universe.

This has been an interesting evidence for sometime now. The referenced article is an addition to the existing evidence of molecules that could be the building blocks of DNA.

[sumeet]

Nothing new or earthshaking about the report, the same has been documented since atleast 60s'. How ever the incremental value of this report is that they are more sure that terrestrial contamination of the sample has not occurred because of the unique neucleotide bases they found, couple of them are not commonly found in earth specimens, but they also say it is found in some viruses. That said it is a far cry from actually finding a DNA or its evidence, which would be more conclusive proof of some form of life, may not even be something we are familiar with. whether there is life elsewhere in universe is one of the most intriguing questions humans have wondered, but perhaps would never be answered categorically in our life times. contrary to mathematical probability theories etc, I am rather skeptical of the possibility of exactly similar conditions elsewhere in universe which would unequivocally support life as we know it.

[Desi]

Nothing new or earthshaking about the report, the same has been documented since atleast 60s'. How ever the incremental value of this report is that they are more sure that terrestrial contamination of the sample has not occurred because of the unique neucleotide bases they found, couple of them are not commonly found in earth specimens, but they also say it is found in some viruses. That said it is a far cry from actually finding a DNA or its evidence, which would be more conclusive proof of some form of life, may not even be something we are familiar with. whether there is life elsewhere in universe is one of the most intriguing questions humans have wondered, but perhaps would never be answered categorically in our life times. contrary to mathematical probability theories etc, I am rather skeptical of the possibility of exactly similar conditions elsewhere in universe which would unequivocally support life as we know it.

100 to 200 billion galaxies, and 100 to 200 billion stars per galaxy and many planets around stars. And stars cool over long periods of time taking planets through various temperature ranges over spans that can be millions of years and the universe is estimated to be 13 billion plus years old. In my view the probability that universe is teeming with life is enormous.

At the same time the distances are so vast that it takes light millions of years to reach us and the probability of us finding the extraterresterial life are next to nothing.

Here are my earlier posts on the topic from 2008

This is an area where I have no hesitation to speculate. And my speculation is that most certain (100%) the universe is teeming with life and chances of us being able to find interstellar life are zero. So, hold no hopes for UFOs with aliens.

My speculation is that universe is teeming with intelligent life. Even though it has taken 4 billion years for life to get to the state it is in on earth and universe is 13.5 billion years old. First 3.5 billion years could possibly be discounted because of star formations and star deaths were needed to create planets, still in the 10 billion years, with 200 billion stars in milky way galaxy alone and hundreds of billions of galaxies, intelligent life is certain.

As to communication, considering the distance and physics and synchronicity issue, I highly doubt establishment of communication or reciept of a signal.

The Drake Equation

[sumeet]

100 to 200 billion galaxies, and 100 to 200 billion stars per galaxy and many planets around stars. And stars cool over long periods of time taking planets through various temperature ranges over spans that can be millions of years and the universe is estimated to be 13 billion plus years old. In my view the probability that universe is teeming with life is enormous.

At the same time the distances are so vast that it takes light millions of years to reach us and the probability of us finding the extraterresterial life are next to nothing.

Here are my earlier posts on the topic from 2008




The Drake Equation

Considering the incredible and mind boggling advances science has made in a trivial period of a couple of hundred earth years and considering that many planets similar to earth (probability of their existence being high), and considering that many of them would be millions of years ahead (relative to earth's time frame), considering that many more technological advances would no doubt take place in times to come including overcoming barriers like limits of speed of light etc, considering that worm holes exist (theoretically making it possible for travel vast distances including another far away part of the universe), while it is a given that at our state of evolution it is virtually impossible to find alien life or even make contact, why is it that some body millions of years ahead of us in the game have not been/ not willing to 'make contact', makes me wonder.

[dcnri2india]

At the same time the distances are so vast that it takes light millions of years to reach us and the probability of us finding the extraterresterial life are next to nothing.

The Drake Equation

While your assertion is very practical given current state of communication technology and knowledge. But almost all of our communication and transportation knowledge is designed to overcome one physical dimension we can observe easily "distance". We have just scratched the surface with other dimensions.

Now given the limitations and physical constraint in our world we may or may not crack this problem in anytime soon, but other "worlds" may not have such limitations or have figured it out.

It is my opinion (no evidence though) that we would be contacted rather than other way around.

On lighter side I knew in my guts Lalu Yadav was "out of this world".


Cheers

[Desi]

Considering the incredible and mind boggling advances science has made in a trivial period of a couple of hundred earth years and considering that many planets similar to earth (probability of their existence being high), and considering that many of them would be millions of years ahead (relative to earth's time frame), considering that many more technological advances would no doubt take place in times to come including overcoming barriers like limits of speed of light etc, considering that worm holes exist (theoretically making it possible for travel vast distances including another far away part of the universe), while it is a given that at our state of evolution it is virtually impossible to find alien life or even make contact, why is it that some body millions of years ahead of us in the game have not been/ not willing to 'make contact', makes me wonder.

You are making many broad assumptions:

1. You are assuming that civilizations of intelligent life can last millions of years. Many natural catastrophes from cooling of the stars, to other natural calamities like the ones that wiped off the dinosaurs or the Toba eruption can kill civilizations much much earlier. I seriously doubt that they would last millions of years.

2. You are assuming possibility that light barrier would be overcome with time - perhaps this is never possible. All of Einstein's and subsequent theories suggest this not to be possible.

3. Then there is synchronicity issue. For us to be contacted, the civilizaiton must have developed at the right point in time and advanced to a point to overcome the barriers of communication and then zeroed in on a specfic galaxy, the milky way and one of the obscure stars from the 100 billion stars in milky and zeroed in on us.

4. Even if all of the above happened and the communications say ended a 1000 years back which is like blink of an eye in astronomical periods and assuming that this communication was very specific, to be made very obvious, we would still have missed it.

All in all, the issues I mentioned earlier and repeated here, Age of civilizations, Time sychronicity, overcoming communication barriers and zeroing in on one of the billion trillion stars in the universe make it next to impossible that we will communicate with other intelligent civilizations.

If a detection of intelligent life elsewhere happens, we would be very lucky, but then that could be 1000 or 5000 years from now. Inspite of the technological progress we have made, we cannot even begin to imagine how much an infant we are if we compare to what will be 5000 years from today. But at the moment, communication beyond the speed of light seems impossible even with future technology based on what we know about light (what happens to the value of mass when we travel say at 0.75 times speed of light).

Even travelling at light speed, it takes billions of years to communicate with star systems in many galaxies.

[boca]

You are making many broad assumptions:

1. You are assuming that civilizations of intelligent life can last millions of years. Many natural catastrophes from cooling of the stars, to other natural calamities like the ones that wiped off the dinosaurs or the Toba eruption can kill civilizations much much earlier. I seriously doubt that they would last millions of years.[/quote]
I don't think that it is an arbitrary assumption (though I don't think you meant it to be arbitrary). It is a natural anthropocentric assumption based on our limited experience, correlated to the almost exponential progress of humans.

What we are currently progressing on is the longevity of life, the protection from the perils and natural hazards of the every day kind. Though the progress may be limited, there is some progress, with promises for more in the future. All these are rooted in the fundamental concept of evolution, our fight to survive. Compared to the period that the dinosaurs lived, human period is a fraction still. That dinosaurs, an organic life form, could live for such a period gives us hope that the chance of humans being wiped out soon is mostly in the hands of humans, than as a result of some volcanic eruption or an asteroid or some virus.

It is hard to imagine, but if the dinosaurs were around for a long long time, I think it is not far fetched thought that humans can be around for a long long time. Unfortunately, with the complexity of the body required for humans, we may be more vulnerable for organic disruptions. But that is just a challenge and we may figure something out.

Again, to reiterate, our aim, thanks to evolution, will be to live longer and to survive for a long long time to come, just as any highly evolved organism. What Sumeet was referring to is such a possibility, that there may be some highly evolved organism by now that figured out a way to survive millions of years.

As to his ponder on why they haven't contacted us, I believe, like Mr. Hawking, that we should be happy they haven't. :) They will probably bite us! Perhaps they have already contacted us and we are just zombies under their control! :)

[Desi]

What Sumeet was referring to is such a possibility, that there may be some highly evolved organism by now that figured out a way to survive millions of years.

Yes and I am not contesting the possibility. I am asserting that the probability of this is extremely miniscule. I listed some conditions like being able to travel trillion trillion miles or be able to send meaningfully obvious signals that must arrive precisely now. The probability of each of these events is extremely slim and overall probability P1*P2*P3 makes such contact almost an impossiblity in my mind. I do not discount human ingenuity, will to survive and unimaginable progress that can happen, but I also think that there are possiblities we can become dinosaurs or Darwinian casualties also. Something like global warming can make us a Darwinian casualty and such cannot be discounted for other intelligent life forms also as well that some life forms perhaps have survived millions of years and yet those millions of years are but a tiny amount in 13 billion years and have to coincide with our era and then their messages need to be targeted to a remote planet on a remote star from one of the 100 billion plus galaxies.