Owing to the fact that it is far easier for a chunk of Mars to travel to Earth than the other way around, it is likely that certain elements necessary to catalyze the formation of biological molecules (like RNA and DNA) came from our neighboring Red Planet. The vehicle for this interplanetary catalytic “seeding” was most likely a Martian meteor.
That’s according to a team of biochemists led by Steven Benner of The Westheimer Institute for Science and Technology in Florida.
Somewhere around 3.5 half billion years ago, the first biomolecules and then single-celled lifeforms emerged on our watery planet. There was “organic soup” aplenty…but one problem: just adding an energetic spark to this soup of molecules merely turns it into a tarry, sticky slime; supra-molecular forms like enzymes and RNA do not spontaneously self-organize in this mixture. No, what is needed is some type of substance — key metallic elements are ideal — that can serve as the catalysts, to get the whole thing rolling. As it turns out, there is a key element — one crucial for biomolecular formation here on Earth — that was lacking from the primordial Earth-scape but was plentiful on Mars.
In a report presented today at the annual Goldschmidt geochemistry conference in Florence, Italy, a team of geochemists (Benner et al) presented compelling evidence that an oxidized form of the metallic element Molybdenum was most likely this crucial, missing catalyst.
In a press statement, Benner elaborated:
“It’s only when molybdenum becomes highly oxidized that it is able to influence how early life formed. This form of molybdenum couldn’t have been available on Earth at the time life first began, because 3 billion years ago, the surface of the Earth had very little oxygen, but Mars did. It’s yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet.”
The geochemist team also stated that another metallic element, boron, could also serve this “jump-start” function here on Earth. However, water tends to impede the accumulation of boron (which is found here only in dry land masses) and there’s water aplenty here on Earth. But Mars – a dry planet — is ideal for boron accumulation.
According to Benner et al, all this water would make it extremely difficult for boron to aggregate in sufficient quantities to support the earliest stages of bio-evolution [note: land run-off of the element from flash-flooding river flows to the sea could have provided this resource].
A watery environment (whether a “warm little pond”, a clay-lined tidepool, deep under a glacier, or near a thermal vent on the sea floor) is believed to have been absolutely necessary to support the matrix of Life. As to the possible role for boron and its origin, Benner also stated:
“Analysis of a Martian meteorite recently showed that there was boron on Mars; we now believe that the oxidized form of molybdenum was there, too,” he said
Further, Benner added, water is “corrosive to RNA”, the self-replicating supramolecule that many who theorize about the Origin of Life believe must have preceded the formation of DNA (a more complex molecule). This is known as the RNA World hypothesis (see: Author Comment, below).
And while so far no evidence of (unicellular) life has been found on the Red Planet, scientists know from discoveries here on Earth that hearty species of microbes — known as extremophiles — can survive and even thrive in quite harsh and foreboding environments. So, it is quite possible that such a unicellular life form (or precursor bio-molecule) could have evolved on Mars, then, upon impact from a large meteor, got blasted off into space in a shower of smaller rocks and headed straight for Earth (note: certain types of chondrite meteorites have been found to contain small amounts of organic matter and even simple amino acids).
And, orbital dynamic studies have shown that (as note above) this Mars-to-Earth direction is far more likely that Earth-to-Mars. Although, it is quite likely that, should we travel to Mars one day, we will surely bring our microbes with us. So, if one day it is proven that life here came from Mars, we will then have the opportunity to return the favor (albeit to a less hospitable world).
The theory is compelling and intriguing and certainly adds more meat to the biogenesis debate. But, in the end, more evidence will be needed to validate this theory, and, of the two planets, Life has found a decidedly more favorable home here on Earth (though we seem to be destroying it at a rapid pace).
But then again, we may be more Martian than we know.
Author Comment:
Mars’ ancient past could likely have supported unicellular life, given the evidence of rivers, canals and “seasonal flows” on its surface. But if this were the case — that there was once water aplenty on Mars — then these arguments against accumulation of boron on Earth would apply to Mars as well, presumably.
Also, indirectly supporting this metal transport theory (and the RNA World hypothesis), is the previous discovery (Robertson and Scott, 2007) of “ribozyme-catalyzed self-assembly of RNA”. These specialized enzymes (known as L1-ligases) are based on a centralized, metal atom-binding structure.
However, this key, metallo-enzyme component need not be molybdenum or boron (manganese works fine). Supporting this, a recent analysis (Johnson et al) of 2.4 billion year old carbonate deposits has found that oxides of magnesium manganese (MnII) were plentiful here on Earth in ocean deposits; these oxides could have been the source of oxygen that served as reactive species to keep the biomolecular motor (an early form of photosynthesis) running strong until the rise of cyanobacteria some 200 million years later (and thus ultimately sparking the “Great Oxygenation Event” {GOE}). [note: the above paragraph has been updated/corrected as of Sept. 5, 2013]
Lastly, regarding Benner’s statement that water is “corrosive to RNA”…this is due to the fact that RNA is a ribose (sugar)-based molecule, and sugars (and their crystal forms) tend to dissociate in water over time. However, Lambert et al have previously demonstrated that a silicate-rich environment (as with clay-lined tidepools, for example) actually protected another sugar (formose) from the normal dissolving power of water, and enabled synthesis of sugar silicates, which led to the formation of ribose (the sugary backbone of RNA and DNA).
So, given these two separate findings, we need not look elsewhere to explain the origins of RNA.
For more on this topic, check out my earlier PS article: ‘In Search of Ancient Alien Microbes & the Origin of Life [Commentary]’
Some source material for this post came from the Space.com news article ‘Earth Life Likely Came from Mars, Study Suggests’ by Mike Wall (via Yahoo News)
Top image: Panorama of Gusev crater, where Spirit rover examined volcanic basalts (credit: NASA/JPL)
The whole universe and all celestial bodies are formed from one mega matter. From this it is logical to conclude that on all the planets exist the conditions for life, but that life hiding underground all the planets. Due to the dispersion of light and the expansion of the universe weakens the energy of the sun and life moves closer to the source, ie the Sun. Conditions and traces of life on Mars is hiding underground Mars, and so all the planets of our solar system. On earth will one day disappear living conditions, but will appear on Venus or Mercury. If it is determined that on Mars life once existed, then all this is a logical truth. Or a simple law of nature, life moves closer to a heat source. It is a natural behavior and life and on Earth with ordinary fire or a hot water source.
The whole universe and all celestial bodies are formed from one mega matter. From this it is logical to conclude that on all the planets exist the conditions for life, but that life hiding underground all the planets. Due to the dispersion of light and the expansion of the universe weakens the energy of the sun and life moves closer to the source, ie the Sun. Conditions and traces of life on Mars is hiding underground Mars, and so all the planets of our solar system. On earth will one day disappear living conditions, but will appear on Venus or Mercury. If it is determined that on Mars life once existed, then all this is a logical truth. Or a simple law of nature, life moves closer to a heat source. It is a natural behavior and life and on Earth with ordinary fire or a hot water source.
” … what is needed is some type of substance — key metallic elements are ideal — that can serve as the catalysts, to get the whole thing rolling.)
What’s going on with the Human Reason at academic community?! Why Humanity is again repeating the same movie that our ancient people made, when their reasoning escaped out of control and they invented religions, magical thinking? What is the key element that gets the fetus, embryos, self-organizing from existing supra-molecular forms? The template coming from parents. Then, what is the key element that gets atoms into supra-molecular forms? The template coming from their parents. Who are the parents that made possible abiogenesis, creating from atoms the molecules and finally the first living being, a complete cell system? This stellar and galactic system. How parents makes their offspring? Genetic code. What is genetic code? Is a nanotechnology resume of a given system. Then, how this galaxy and this stellar system made the first biological system? As a microscopic copy of itself, mutated due different materials and initial conditions.
So, the logical thinking is searching how this galaxy and/or stellar system fits as the template for the first biological system. I did it and the result is a new cosmological model for astronomic system formation and function that fits as the template for cells systems. And the conclusion that our problem trying to elucidate the life’s origins is due our modern academic astronomical model which is wrong. I am challenging any person to point out a scientific proved fact that debunks the models of Matrix/DNA Theory. You can see there the Matrix universal formula that Nature has applied for formation of all natural systems, from atoms to galaxies to human beings. I can’t understand why people lose the control of their natural “Reason”, which is a natural product! Matrix/DNA Theory suggests that this two steps of life’s formation at two different planets is possible, and not only two, but seven steps.
” … what is needed is some type of substance — key metallic elements are ideal — that can serve as the catalysts, to get the whole thing rolling.)
What’s going on with the Human Reason at academic community?! Why Humanity is again repeating the same movie that our ancient people made, when their reasoning escaped out of control and they invented religions, magical thinking? What is the key element that gets the fetus, embryos, self-organizing from existing supra-molecular forms? The template coming from parents. Then, what is the key element that gets atoms into supra-molecular forms? The template coming from parents. Who are the parents of the first living being, a complete cell system? This stellar and galactic system. How parents makes their offspring? Genetic code. Then, how this galaxy and this Sin’s system made the first biological system? By a genetic code. What is genetic code? Is a nanotechnology resume of a given system.
So, the logical thinking is searching how this galaxy and/or stellar system fits as the template for the first biological system. I did it and the result is a new cosmological model for astronomic system formation and function that fits as the template for cells systems. And the conclusion that our problem trying to elucidate the life’s origins is due our modern academic astronomical model which is wrong. I am challenging any person to point out a scientific proved fact that debunks the models of Matrix/DNA Theory. You can see there the Matrix universal formula that Nature has applied for formation of all natural systems, from atoms to galaxies to human beings. I can’t understand why people lose the control of their natural “Reason”, which is a natural product! Matrix/DNA Theory suggests that this two steps of life’s formation at two different planets is possible, and not only two, but seven steps.
Life on earth came from organic hydrocarbons ,which has been seeped up on the surface of the earth from mantle level conditions in past geological time like Titan’s hydrocarbons . fossil fuel theory is not correct however it is true that commercial interesting accumulations of hydrocarbons has been expelled from organic rich sedimentary rocks but those only which has been formed with left over abiotic hydrocarbon bearing sludge. sediments that has been formed without any involvement of this abiotic hydrocarbon bearing sludge are dry hole and this is one of the main reason because main basic material of kerogen and bitumen is absent in these type of sediments. there is no scientific paper showing that deceased organic matter is the only basic raw material of kerogen and bitumen. yes i agreed biotic characteristics has been injected in the burial history of the mixture of organic matter+abiotic hydrocarbon bearing sludge ( once present on the surface of the earth and has been reburied after mixing with the organic matter)
http://www.universetoday.com/12800/titan-has-hundreds-of-times-more-liquid-hydrocarbons-than-earth/
[email protected]
Life on earth came from organic hydrocarbons ,which has been seeped up on the surface of the earth from mantle level conditions in past geological time like Titan’s hydrocarbons . fossil fuel theory is not correct however it is true that commercial interesting accumulations of hydrocarbons has been expelled from organic rich sedimentary rocks but those only which has been formed with left over abiotic hydrocarbon bearing sludge. sediments that has been formed without any involvement of this abiotic hydrocarbon bearing sludge are dry hole and this is one of the main reason because main basic material of kerogen and bitumen is absent in these type of sediments. there is no scientific paper showing that deceased organic matter is the only basic raw material of kerogen and bitumen. yes i agreed biotic characteristics has been injected in the burial history of the mixture of organic matter+abiotic hydrocarbon bearing sludge ( once present on the surface of the earth and has been reburied after mixing with the organic matter)
http://www.universetoday.com/12800/titan-has-hundreds-of-times-more-liquid-hydrocarbons-than-earth/
[email protected]