Physics -> Chemistry -> Biology
The Smithsonian Magazine has an article this week proposing that we consider Mars as the origin of Terrestrial Life. This notion stems from Steven Benner’s Four Paradoxes: The Tar Paradox, The Water Paradox, The Single Biopolymer Paradox and The Probability Paradox. Each of these is described in the abstract of his work, and do add up to a possible alternative for life’s origin. However, as compelling as his arguments may be, the origin of life will always be a mystery veiled in time. Even if we were to find evidence of life on Mars that is very much like that on Earth, it would be difficult to say whether Terrestrial life was the origin of Martian life, or vice versa.
Another problem I have with tracing the origins of life off-planet is that it does not solve anything, but merely relocates the source. So it’s not that I feel that Benner’s work is uninteresting or unworthy of consideration, but presently, Ockham’s razor precludes 
seriously considering extra-terrestrial origins without a good deal more hard evidence. Further, relocating the source or life’s origin does little to change how we think about origins. Regardless or where life started, it is still highly probably that it began with RNA, a unique molecule in that even today it serves dual roles as an information-carrying molecule and a structural one that often has enzymatic function. And, that the addition of the more stable , DNA molecule as the primary source of information happened later – as adding protein synthesis also did for providing an alternative structural / functional molecule.
Evolution of the Central Dogma?
RNA
DNA -> RNA RNA -> Protein
DNA -> RNA -> Protein
DownHouseSoftware 
Erik Andrulis
September 3, 2013 at 1:48 pm
I agree with your skepticism towards pushing the problem off the planet. You’d still have to explain where *that* life came from.
“However, as compelling as his arguments may be, the origin of life will always be a mystery veiled in time.”
Perhaps so, if one abides by convention. But, seeking the answer to that mystery, I devised an empirically consistent theory.
Oh, and by the way, the central dogma is wrong; has been for a long time.
downhousesoftware
September 3, 2013 at 5:27 pm
Thanks for the comment, Eric.
Please share. I find it difficult to imagine any explanation offering more than a decent model within which life is possible.
I’m also interested to hear what you are referring to with respect to the Central Dogma. I agree that there are examples where the Central Dogma fails, but as it’s an excellent rule of thumb for tracing information through a cell.
Sincerely,
Jack
nccomfort
March 24, 2016 at 10:13 am
Found this post while searching for the source of the Szent-Györgi quote. It’s also a favorite quotation by folks such as William Martin and Michael J. Russell. They use it in reference to their thermodynamic explanation for how life is an *inevitable* consequence of certain, rather common, starting conditions. In short, everything, from the Big Bang to the origin of life to consciousness, is a cascade of dissipations of energy. It’s entropy, all the way down. Recommend their papers, as well as a handful by Harold Morowitz and Eric Smith from a few years ago. It’s a model, yes, but it’s not only testable, it’s being tested, bit by bit, by folks such as Laurie Barge at JPL. Cool stuff.
downhousesoftware
March 24, 2016 at 3:35 pm
Thanks so much for stopping by and even more so for the comment. I’ll look into the papers you suggested.