The essence and origins of life. What is it? Yes, we can define characteristics that differentiated the living from the non-living. The building blocks of life are still not the same as a simple virus. Do you think new forms of life "become living" these days?. Do you think that the conditions to form new life simply do not exist anymore? Evolution can not even begin until something (still yet unknown to us) happens first. Do you think we will ever discover the recipe?
It's not a matter of faith. It's a question of possibility. I don't "believe" in the existence of extra-terrestrial life; I think it may be possible. That's closer to agnosticism. We cannot disprove the hypothesis that extra-terrestrial life (DNA-based or otherwise) may exist until we have surveyed the universe--so there is always going to be some uncertainty.
Craig Venter the inventor?
To Robert Piano:
LWikipedia: L is the twelfth letter of the ISO basic Latin alphabet. →
I think earth is ripe with the possibility of new 'life' forming - depending on how one defines life. One problem, however, is that so much life already exists that newly formed life has to compete with other life that has adapted for billions of year.
In a much shorter time span, the micro-organisms that invade my home brewed wine need to compete for nutrients with yeast that has been adapted for thousands of years to survive a somewhat acidic, rather ethanol rich environment. Furthermore, that yeast has been cultured for centuries to survive in a rather sulfur rich environment that kills most micro organisms.
New occurrences of self organizing structures have a lot of competition from micro-organisms that already have adaptive facility to the environment. I highly doubt that a brand new, simple, self organizing structure stands much chance of getting anywhere these days - at least on earth.
It would be difficult, if not impossible, for there to be free-floating organic molecules for some new life to even begin to form from, just for starters! Not only would something new be eaten for lunch, but more than likely its would-be constituents have already been lunch.
Unless such life can arise from stuff that current life (which is basically saturating the earth already) cannot use, it's hard to see how such could arise other than under very, very odd and probably artificial circumstances (a big batch of organic molecules, somehow sterilized).
I think we're past the starting position for the original creation of life. The circumstances that existed then simply don't exist here anymore, and since we don't know precisely what those particular circumstances were, even simulating them in a lab is very hit and miss.
The whole question of how life arose has been a tough nut to crack, scientifically. And in part it's for the reasons you allude to here--the conditions have changed--life itself has changed many of them, ironically--and we don't really know what they were.
It gets worse if it turns out to be a very improbable event, because whatever the process is, it will depend on something really unlikely happening, so the actual correct explanation would probably be dismissed as ridiculous (remember those cartoons of the scientists talking over a diagram that has "and then a miracle occurs" in the middle of it?) even if someone were to hit on it.
The original conditions giving rise to life may be ridiculously rare, but not nearly as rare as an infinite number of monkeys evenually typing Shakespeare's Hamlet. Given that the latest estimate of the number of stars is 300 sextillion, and the number of planets 3 or 4 times that number at least, the conditions that brought about life here are almost certain to happen elsewhere, not just in a few places but in a great many.
I quess, because of the vast distances, and low probability of encounter, there are lots of 'dreamers' in the universe, waiting. And I expect a few hungry predators...;p)
Our planet came into existence around 4.6 billion years ago. We have existed in some shape or form for somewhere between 100,000 and 250,000 years, and have understood the concept of alien life potential for probably less than 100 years. It is not a matter of size of alien, intelligence of same, ability to get to us, or any other element. The timing of such a life form's also becoming aware of space, within those billions of years would have to match ours. So it would have to time its evolution to a mighty fine degree to be at roughly the place we are in our awareness today.
Would an evolved life form even recognise us as worth bothering with. Looking at us through the lense of about 250000 years seems hardly worth mentioning. If another life form had millions of years of writen cultural history, surely ours would be only interesting in passing. While we were just getting the hang of tool making, they were exploring intersteller space, and starting to evolve on other planets for adaptation.
Unless we are atypical, it's not likely most other races will go on for anything like 250,000 years as civilized beings. We've had civilizations for perhaps 10,000 years or less.