To help focus the search, scientists can glean clues from the burgeoning field of synthetic, or artificial, life. Biochemists are currently attempting to engineer completely novel organisms by inserting additional amino acids into proteins. A pioneer of this research, Steve Benner of the Foundation for Applied Molecular Evolution in Gainesville, Fla., has pointed out that a class of molecules known as alpha-methyl amino acids look promising for artificial life because they can fold properly. These molecules, however, have not been found in any natural organism studied to date. As investigators identify new microbes, it would be a relatively simple matter to use standard tools for analyzing the composition of proteins, such as mass spectrometry, to learn which amino acids the organisms contain. Any glaring oddities in the inventory would signal that the microbe could be a candidate for shadow life.
If such a strategy were successful, researchers would face the difficulty of determining whether they were dealing with a genuine alternative form of life descended from a separate origin or with merely a new domain of known life, such as archaea, which were not identified until the late 1970s. In other words, how can scientists be sure that what seems like a new tree of life is not in fact an undiscovered branch of the known tree that split away a very long time ago and has so far escaped our attention? In all likelihood, the earliest life-forms were radically different from those that followed. For example, the sophisticated triplet DNA code for specifying particular amino acids shows evidence of being optimized in its efficiency by evolutionary selection. This observation suggests the existence of a more rudimentary precursor, such as a doublet code employing only 10, rather than 20, amino acids. It is conceivable that some primitive organisms are still using the old precursor code today. Such microbes would not be truly alien but more like living fossils. Nevertheless, their discovery would still be of immense scientific interest. Another possible holdover from an earlier biological epoch would be microbes that use RNA in place of DNA.
This article was originally published with the title Are Aliens Among Us?.
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58 Comments
Add CommentIt's curious there is no discussion of a coding system. Without one, evolution is difficult to conceive. This would seem to be the far more important key to this field.
Reply | Report Abuse | Link to thisIt's funny that thier isn't a scientist that thinks we could just be experiment in the Universe and this is all a test to advance humanity.
Reply | Report Abuse | Link to thisIt was a very interesting article.
Reply | Report Abuse | Link to thisI agree jin lee. it is a very interesting article. thought-provoking and timely as far as my interests are concerned. i've been working on the idea of bio-responsive adaptive integrated systems. would entail the use of silicon nanoribbons built-up layer by layer with three different types of channels. micro- & nanofluidics is crucial to making this type of network function. there is some evidence that blood may actually be the 'driving' force behind the brain's function. inasmuch as coding is concerned it is likely to be the result of quantum chemistry. likely QIP is non-random but inherent property of the system. evolutionary traits or properties are possibly simple consequences of environmental parameters. Potentially when we solve the complexity code we will be amazed at how simple it was when it all really started. As to the question as to whether intelligent life exist elsewhere in the Universe, I'm sure a few of us are still seeking it on Earth. :)
Reply | Report Abuse | Link to thisNeat stuff.
Reply | Report Abuse | Link to thisAnd...the whole! piece.
thnx.
[looked for adenine and adenosine but didn't find this key
compound.]
Something seems wrong with the idea that arsenic could successfully replace phosphorus for living organisms. Phosphorus is primarily used in phosphate esters, like in DNA and ATP. The main advantage of phosphate esters is that they are thermodynamically unstable while kinetically stable due to its pKa and resulting negative charge at physiological pH. ATP has an extremely long non-biological half-life, and this works well so that the organism can control the utilization of energy. However, arsenic esters hydrolyze completely in neutral water within a few minutes. Plus, pentavalent arsenic is much easier to reduce than pentavalent phosphorus, resulting in oxidative damage. I suppose it's not impossible to use arsenic, but it would seem it simply cannot confer the stability and control needed for prolonged survival.
Reply | Report Abuse | Link to thisWhy not try to isolate alien microbes by using a nutritional broth to wish is added a mixture of antibiotics. Many antibiotics have a specific target on bacteria where they e.g. influence the bacterial metabolism or e.g. the synthesis of the cell wall. These specific targets are not likely found in alien life, since they must have evolved at least slightly different pathways. To my view this is the most obvious way to isolate either alien life or a new domain of known life.
Reply | Report Abuse | Link to thisFurther more I would suggest using low levels of simple nutrition in the search for alien life to avoid possible toxic effect.
It is possible that RIchard Hoover and Elena Pikuta have already found indirect evidence for a shadow biosphere. After all, why would A. multivorans have evolved the ability to metabolize molecules of the wrong chirality unless there were at least semi-reliable sources of these molecules?
Reply | Report Abuse | Link to thisI think George W. Bush is an alien organism and is trying to destroy the entire planet. Definetly, scientist should do extensive research on him.
Reply | Report Abuse | Link to thisSeems improbable to have alien life among us simply because since conditios for life first arising only existed for a short time, any other life that arose at that time would have been out competed. No?
Reply | Report Abuse | Link to thisIf the conditions for life to arise only existed for a short time, even if two independant forms of life arose, wouldn't the fitter form have simply outcompeted the other one right from the start, leaving no evidence of their existence?
Reply | Report Abuse | Link to thisProbability discussions make abiogenesis the ever-elusive dream. The logical inference to the best explanation is that God created life.
Reply | Report Abuse | Link to thisIf God (supposedly all-wise) created life, why is it so raggard and wayward in its expression - from slugs to baboons?
Reply | Report Abuse | Link to thisExplanation by reference to God is to explain nothing. If God created Life, then some sort of process was involved. Science wishes to understand that process. Unless, of course, one subscribes to a view of the universe from a totally time limited, earth centric, human dominated view. I don't. Rather, I accept the possibility of One, Infinite Being as a noumenal cause. But I still like to know how it was done. RMMoore
Reply | Report Abuse | Link to thisThe universe is built from matter (including energy and EM radiation). This matter is governed by a large set of natural laws. Many of these laws are still unknown and awaiting to be discovered. It appeares that life is resulting from the consequential action of these unknown natural laws.
Reply | Report Abuse | Link to thisA near infinitity of time, space, and material renders even the remotest possibility a near certainty. It's only the ancient madness of an infinite god or gods outside space and time who thinks universes into existence that is neither rational nor probable at any extreme.
Reply | Report Abuse | Link to thisDark matter, dark energy... and now dark living beings?
Reply | Report Abuse | Link to thisthis thory of the orgin of life has the problem that it cannot be proven, right or wrong, so it can't be science
Reply | Report Abuse | Link to thisThings you need: not too far, not too near the home star, a moon to maintain tides so the oceans don't stagnate, a molten core for magnetic field protection from cosmic rays, the right size for enough gravity to hold down an atmosphere (problem with small Mars), a large outer Jupiter to catch asteroids so they don't interrupt the evolution of life. So, what's the prob. of all these things coming together?
Reply | Report Abuse | Link to thisAnother angle on this issue can be to consider broadening one`s definition of life. Core features of many definitions might include capacity for reproduction, passage of structural information from one generation to another, ability to utilize energy to foster growth, and ultimately, in the case of advanced life forms, to think or be self-conscious. If one broadens one`s definition far enough, one can consider a star, or a rock, or any system of particles, to have properties of this type (we do have geological & cosmological life cycles). Perhaps there is a type of grandiosity or narcissism in the idea that only the chemical forms of which we are familiar meet the definition of life. I do not mean this in a mystical way, but in a very objective scientific sense, that perhaps the whole universe could be considered alive, and perhaps all subsets of the universe are also alive. Biological organisms on the earth may only be a specific, highly specialized subset.
Reply | Report Abuse | Link to thisI might be helpful to establish certain scenarios in this regard, that would actually lead from smaller chains of atoms to larger ones capable of reproducing themselves more of less infinitely. This seems to be the part of this theory that is lacking, here, in terms of "30 nanometer organisms without DNA". How do they originate from scratch, and how do they turn into something completely different later on? We have the old lagoon theory, here, that is all. terms of life arriving from another solar system, we lack a second series of scenarios that would take those organisms across dozens or hundreds or thousands or millions of light-years of bitterly cold, empty, airless, gravity-free space, without losing its own life in the process. I think this is the major flaw in this article, in fact. It sort of assumes spaceships, flying saucers, hyperdrive, and a Klingon civilization out there somewhere. If so, where are they and what are they doing for fun this fall, anyway?
Reply | Report Abuse | Link to this.
Reply | Report Abuse | Link to thisvery old question, indeed
have you seen the space-locusts of Independence Day?
they fly from planet to planet destroying everything
well... what are WE ("humans") doing to this planet?
maybe... WE are the real "aliens"?
...and the "bad aliens" (that, someday, will come from Space) may save us and our planet from ourself?
too much philosophy? ... :)
.
off-topic but interesting...
take a look at MORE moons running around the Earth in this Flash animation:
http://www.ghostnasa.com/posts/014manymoons.html
.
--
Edited by gaetanomarano at 11/21/2007 3:59 PM
If the conditions for life arising only existed for a short period several billion years ago and 2 or more independant life forms arose, wouldn't the fitter variety of life (ours) have simply outcompeted the others and left no traces of the other forms? I assumed it left no traces because this outcompetition would have occured so early on that no fossilized records would have been formed and lasted this long.
Reply | Report Abuse | Link to thisnot impossible , if life has evolved in other worlds, then space exp'loration must consider the alternative of one way Biological compativility exploration missions , just in case .
Reply | Report Abuse | Link to thisMarco Flores
Often we look for evidence of other lifeforms outside of ourselves yet the answers lie within our own bodies. Through our soul, our intuitive, our tailbone, our gills, and wingbones we know that there is a physical comparison between ourselves and other life. Because we are third dimensional much knowledge has been lost to us in the past but now the time is here to learn about our galactic angelic ancestors and other life throughout the Milky Way Galaxy. Look at the variety of species on Earth and the numbers of stars and planets, wouldn't be egotistical to say that we are the only human life or life in the galaxy? This thought does not go along with the laws of nature.
Reply | Report Abuse | Link to thisWhat kind of material existed before the big bang-was it possibly a long string with seperate time and seperate space on it - along with GOD?
Reply | Report Abuse | Link to thisThe earth and life exist because of an extraordinary series of random happenings which evolution continued, and, will continue.
Reply | Report Abuse | Link to thisHaven't read the article yet (just got the hardcopy version). It did raise this question; what if that other life used different nucleotides or different numbers of nucleotides instead of the four life as we know it uses?
Reply | Report Abuse | Link to thisWould we recognize an organism as being alive if it use three nucleotides, or six? What if it used ATP as a unit of heridity instead of optimizing energy use?
Might we have samples of other life already to hand, stored away because researchers don't know how to handle them?
I hope this article inspires future research. The possibility that biogenesis could have occurred more than once right here on Earth has an enormous amount implications for the life sciences and again re-opens the Earth as vast and unexplored.
Reply | Report Abuse | Link to thisInspiring article - and a subject well worth investigating. This is the sort of thing to which our research resources should be devoted. rather than to devising ever new ways of destroying the life - or at least the megafauna - that does exist on this planet....
Reply | Report Abuse | Link to thisHenri
Come on, Paul and others, you see very well yourself that it's nothing more than superficial speculations and vain empiricism, that “post-modern†kind of science after the end of science. In this sense, I agree with the above comment by Biocab: “Dark matter, dark energy... and now dark living beings?†Just ever more elaborated plays on words serving to hide the terrible, persisting, untreatable absence of understanding by the official science of the phenomenon of life, starting already from its terrestrial, “well-known†version. Instead of spending ever more resources for “futuristic†nothingness (like their test-tube creationism – quelle connerie!), it would be more honest – and practically efficient – to recognise that something essential is missing in the conventional science doctrine that cannot understand not only the “unlimited†complexity of life, but even the real, physical structure and dynamics of the simplest material object of the universe, the isolated electron. Another, causally complete kind of knowledge and related genuine understanding of natural system complexity they now dare to strongly modify (and destroy!) is not impossible (see e.g. http://arXiv.org/abs/physics/0502133 , http://hal.archives-ouvertes.fr/hal-00156368 ), but it is rather such, currently neglected studies and approaches that should be favoured in today's situation. It means, Paul, that even dealing with “particular†problems, we cannot avoid answering those “general†questions of your preference about the “ultimate†origin of laws, universe, life and consciousness. They just emerge all together, particular and general problem solutions (e.g. http://arXiv.org/abs/physics/0601140 ), and thinking deeper about it, could it be otherwise, within a consistent, efficient world and knowledge structure? It can only be otherwise within a contradictory, frustrated and extremely superficial form of knowledge based on plain empiricism and sectarian “mysteriesâ€, such as the official science still imposed and dominating in all your best labs and universities. But now it's time to change, Paul, don't you feel it? Or else the empty, dark eyes of the Cosmos may soon see one civilisation less in its infinite space of possibilities. It's time to prove that “ourâ€, terrestrial life form can give rise to real consciousness, with its genuine understanding of reality such as it is, instead of “nice†superficial chatter around always unsolved problems and infinite play with esoteric mysteries.
Reply | Report Abuse | Link to thisWell researched article, touching on several aspects of the possible origins of life. Please update this in future as more research is done.
Reply | Report Abuse | Link to thisI see the potential for the biogenesis and the co-existence of alien life forms with native life forms in the same way that we ecologists and microbiologists continually witness the co-evolutionary symbiotic relationship of newly invading parasite and host (e.g., endosymbiosis of initially aggressive virus and host). Perhaps alien life forms already make up our known life forms (e.g., live inside us) and we are simply not in the position scientifically to recognize these alien organisms which would use a radically alternative biochemistry. There are far too many ultra-small particles currently identified but not understood that reside in our cells and bodies. The burgeoning field of nano-technology and science will give us some very interesting answers&and certainly more questions!
Reply | Report Abuse | Link to thisYou can get more of my thoughts on the subjects of alien life forms, endosymbiosis, autopoiesis, synchrony and co-evolution on my blog, The Alien Next Door (http://sfgirl-thealiennextdoor.blogspot.com/).
Reply | Report Abuse | Link to this--
Edited by nina munteanu at 12/03/2007 12:35 PM
The article was very imformative to read-- Thank you.
Reply | Report Abuse | Link to thisI was recently told that chickens lay their eggs a hour later each day. So that makes 25 hours between eggs. Now doesn't Mars have about a 25 hour day? Could chickens be aliens from Mars? Alas, my greatest fear is that someone will take this seriously.
Reply | Report Abuse | Link to thisif alien exist...than y dnt they visit us?they must be our enemies...
Reply | Report Abuse | Link to thisaliens might not be alien if they were here before we got here , paralel evolution and convergent evolution is another possibility .
Reply | Report Abuse | Link to thismarco
Archea and bacteria occupy two completely different environments that is how they were able to avoid competition. They did not peacefully co-exist in the same environment.
Reply | Report Abuse | Link to thismetorites are extraterrestrial because they come in frozen ice particles is this true.
Reply | Report Abuse | Link to thiswell i think that there is alien matter on earth occuping somethin.
Reply | Report Abuse | Link to thiswhat does microbes contain in aliens.
Reply | Report Abuse | Link to thiswill it affect the human life or will it makes us superhumans. like a extra chromosome in the human body.
does help life itself.
Reply | Report Abuse | Link to thisor is it more complex than that.
I think we would be unlikely to find them because of ecological interactions, they could have been out competed by native organism, preyed upon, symbiotically "assimilated" as are mitochondria now living in our bodies and having lost most of the genetic material. good luck finding them - unless they are relatively recent arrivals
Reply | Report Abuse | Link to thisOnce life evolved on earth, it changed earth so that the conditions were different. Maybe life could evolve again, but how would it keep from being eaten?
Reply | Report Abuse | Link to thisArchaea and bacteria do in fact share many of the same habitats. Presumably they evolved about the same time.
Wait a second!
Reply | Report Abuse | Link to thisHow old is the universe?
Now we are to suppose that life evolved out of nothing on an alien planet somewhere and then travelled to Earth.
Which planet?
How did it get here?
What conditions are necessary for abiogenesis?
Star Trek and Star Wars are for fun.
They are not real, or are they?
Given the infinite possibility argument then Star Wars really could have happened, along time ago.
But there is not that much time is there?
If there is infinite possibility, then what exludes the idea of god as a possibility?
Anyway, I blame TV. Without William Shatner and co going boldly, I am sure that fantasy would not pass for science.
What a thrilling prospect! If I were going to college, I'd consider studying such new and exotic microbes as a career. You know that the truth of these alternative life forms will be stranger than fiction. Huge discoveries are just waiting to be made in this field, but who's jumping on it? Is there any profit to be made? I guess that's why there is no mad rush to try to answer these questions.
Reply | Report Abuse | Link to thisHello sir this is Raghavendra My father Jayram Br has found the interesting facts regarding the skylab & about the planets mars . We have even broadcasted the facts on 17/02/2008 at LIVE PROGRAM, The research that we are carrying matches up to your research too, i wish you would understand the further movements,
Reply | Report Abuse | Link to thisMR,JAYARAMA.BR
#94,5th Cross, Nanjappa Garden, Babusapalya, Nanjappa Garden, Kalyanagar post, Bangalore, Karnataka, INIDIA,91-9900900019.
91-9945610373.
www.mr.raghav2008@rediffmail.com
Interesting I guess all I have to say to that is [url http://alien-ufo-research.com][/url]
Reply | Report Abuse | Link to thisDid anyone consider the possibility that we are the aliens on this earth? Perhaps this was the garden or eden and our sin was to infect this garden by not listening to God's proticals?gunondeer
Reply | Report Abuse | Link to thisI think the two different life-forms scientists are looking for is right in front of our faces... Plants. Alive but fundamentally different.
Reply | Report Abuse | Link to thisI don't agree with your definition of life. Is a rock dead or is it alive?
Reply | Report Abuse | Link to thisAssuming you believe in a heaven and in eternal life, do the beings in there reproduce, grow and multiply like on earth?
It's possible that life and death (with one cannot exists without the other) might be part of something greater like consciousness.
The article was a bit contradictory regarding the stability of genetic codes. The codes can be subject to evolutionary drift only if they are not resilient to mutation.
Reply | Report Abuse | Link to this
Reply | Report Abuse | Link to thisThe Media...
Have you ever noticed the the name 'robert' or any version of that name..ie..bob, bobby, rob, robyn..ect..is in the main credits of just about EVERY movie..sitcom..police show..ect that is on TV?! (also, nearly every movie has someone in it by that name..ie..a Mr. roberts, bobby..ect). The main credits being the producer or ass. producer, director, written by.. and so on. You may say that it is just because the name has been focused on but it will NOT happen with any other name..even the most popular of names.
I live in australia and, at the moment, just in advertising, the name is used sooo much. For eg...
bob the builder
bob the lotto� guy
bob the lender
rob the dentist
robyn the dentist
robyn the vet
now iinet has 'bob' ..(singing alleluha to it!!!!)
bob the apprentice
bob the funeral insurance..
Let's take just one show for example..the simpsons..is there a bob on that? YES!
Now check out the credits on your movies/cop shows at the beginning or end of the show and, most times,he'll be there!!How many roberts are there in the movie business?
doesn't stop there either!
I have two� pages of the name robert in gov./police/ etc. I won't give out full names but here are just a small amount...
Deputy att gen-robert
police com-robert..
enviroment min.-robert..
state opp. justice-robert..
shadow police com-robert..
attorney gen-robert..
judge supreme court.-robert..
chief med. off-robert...
finance min-robert..
I could keep going,
transport min..roberts, defence min..robert, tourism min...robert, war crime judge...robert, state police� com...bob.
had enough??
The name has infiltrated into the society in nearly ALL ares of media and government!
Just wondering...have you ever heard of valient thor?
Thankyou for your Time. Sharon.
Check out the next american movie..(your name rob? someone who works for you?)
Reply | Report Abuse | Link to thisThe Media...
Have you ever noticed the the name 'robert' or any version of that name..ie..bob, bobby, rob, robyn..ect..is in the main credits of just about EVERY movie..sitcom..police show..ect that is on TV?! (also, nearly every movie has someone in it by that name..ie..a Mr. roberts, bobby..ect). The main credits being the producer or ass. producer, director, written by.. and so on. You may say that it is just because the name has been focused on but it will NOT happen with any other name..even the most popular of names.
I live in australia and, at the moment, just in advertising, the name is used sooo much. For eg...
bob the builder
bob the lotto guy
bob the lender
rob the dentist
robyn the dentist
robyn the vet
now iinet has 'bob' ..(singing alleluha to it!!!!)
bob the apprentice
bob the funeral insurance..
Let's take just one show for example..the simpsons..is there a bob on that? YES!
Now check out the credits on your movies/cop shows at the beginning or end of the show and, most times,he'll be there!!How many roberts are there in the movie business?
doesn't stop there either!
I have two pages of the name robert in gov./police/ etc. I won't give out full names but here are just a small amount...
Deputy att gen-robert
police com-robert..
enviroment min.-robert..
state opp. justice-robert..
shadow police com-robert..
attorney gen-robert..
judge supreme court.-robert..
chief med. off-robert...
finance min-robert..
I could keep going,
transport min..roberts, defence min..robert, tourism min...robert, war crime judge...robert, state police com...bob.
had enough??
The name has infiltrated into the society in nearly ALL ares of media and government!
Just wondering...have you ever heard of valient thor?
Thankyou for your Time. Sharon.
Check out the next american movie..(your name rob? someone who works for you?)
Reply | Report Abuse | Link to thisThe Media...
Have you ever noticed the the name 'robert' or any version of that name..ie..bob, bobby, rob, robyn..ect..is in the main credits of just about EVERY movie..sitcom..police show..ect that is on TV?! (also, nearly every movie has someone in it by that name..ie..a Mr. roberts, bobby..ect). The main credits being the producer or ass. producer, director, written by.. and so on. You may say that it is just because the name has been focused on but it will NOT happen with any other name..even the most popular of names.
I live in australia and, at the moment, just in advertising, the name is used sooo much. For eg...
bob the builder
bob the lotto guy
bob the lender
rob the dentist
robyn the dentist
robyn the vet
now iinet has 'bob' ..(singing alleluha to it!!!!)
bob the apprentice
bob the funeral insurance..
Let's take just one show for example..the simpsons..is there a bob on that? YES!
Now check out the credits on your movies/cop shows at the beginning or end of the show and, most times,he'll be there!!How many roberts are there in the movie business?
doesn't stop there either!
I have two pages of the name robert in gov./police/ etc. I won't give out full names but here are just a small amount...
Deputy att gen-robert
police com-robert..
enviroment min.-robert..
state opp. justice-robert..
shadow police com-robert..
attorney gen-robert..
judge supreme court.-robert..
chief med. off-robert...
finance min-robert..
I could keep going,
transport min..roberts, defence min..robert, tourism min...robert, war crime judge...robert, state police com...bob.
had enough??
The name has infiltrated into the society in nearly ALL ares of media and government!
Just wondering...have you ever heard of valient thor?
Thankyou for your Time. Sharon.
Check out the next american movie..(your name rob? someone who works for you?)
We the people of earth are totally foolish to believe that we are the only life forms in the universe and we are definitely NOT.
Reply | Report Abuse | Link to thisHello all, I like all your thoughts, but why is it you need to explain that life on earth is more than an accident or at best a marvel of nature, if alien DNA does exist on this planet well it came from somewhere else, hence alien! Why do you you think it had something to do with us and even then if it did it came from its own accident or marvel from far away. Yes the variations are far more vast than we can understand but in the end to find some reason for our beginning is not going to help our future. It is all good to swap base building blocks and see what we would be if we were made from something else but life has not made us from something else, and as we are formed to live specific to our environment other life is created to live in there's without all the complications of space travel, life is not made to travel so far or live so long, do you really think our DNA on board our space craft have lasted the journey outside our solar system? Why do you think other have made it here, you are all smart people, are you not. I don't believe in GOD,I believe in life. It happened on this planet, and in all honesty it has happened on others maybe not to the extent of the human capabilities but life nun the less. And then of human capabilities well to be honest we are still a planet that kills and fights over gods daily, and those that work in the name of science do so for money. Look to our stars, ask the questions but if you really want the answers, look to making a better people, they are watching.Why would they let you find them, remember that are smarter than us!
Reply | Report Abuse | Link to this