Life on Mars

We estimate that Planet Earth formed roughly 4.5 billion years ago. A mere 500 million years later, its first and only ever living molecule (DNA/RNA) concresced. Today, organisms descended from that one molecule cover nearly every inch of the planet and manage to survive, nay thrive, in unimaginably hostile environments. A single human body consists of 30 trillion of these resilient little critters.

Planet Earth is infested, infested with life! Like a ball of popcorn, soaked in honey and left lying out in the hot sun, we can no longer see the ball through the swarm of ‘beneficiaries’ covering it.  

“Its first and only ever?” There is no evidence that life evolved more than once on Earth. Had it, its various forms would probably not have been compatible. Perhaps none of those forms would have survived. Best case, a single architectural design would have quickly won out (as it did?). 

Given the state of things on Planet Earth 4 billion years ago, it is natural to wonder how likely it was that a living cell would have emerged? But probability doesn’t enter-in to this discussion! It happened once, period. There’s no guarantee it will ever happen again; make the most of it!

We’re left trying to construct a probability matrix based on a sample of one; can’t do it! Imagine you have never seen a deck of playing cards before. Your terrestrial life coach invites you to ‘pick a card, any card’, and you do. Ace of Clubs. Now, what’s the probability that the next card drawn will also be an Ace of Clubs?

We know that the answer is 0. But we know that only because we know how the deck is constructed. Absent that information, the question itself is meaningless. Of course, once we start finding life forms ‘off-Earth’, it will be a whole different ball game, but that time is not now.

Which means biogenesis on Earth (x) could be just shy of ‘infinitely likely’, or of ‘infinitely unlikely’, to have occurred. So all we can say about P(x) is that P(x) > 0 but < 1. 

Given that life has evolved only once on Earth in 4 billion years and, as far as we know, nowhere else in our solar system, it is impossible to assert that biogenesis (x) has any real probability at all: i.e. that P(x) є {R}. 

Sidebar #1:  If {R} > P(x) > 0, we can say that P(x) is hyperreal. While we cannot say that x is possible, we cannot say that x is impossible either. Is this the statistical model of agnosticism?

Sidebar #2:  If {R} > P(x) > 0, is (x) the mathematical definition of a miracle? 

Given what we know (a lot) about conditions on Earth over the subsequent 4 billion years, how likely is it that such a life form would have survived? Common sense says that if life only evolved once on Earth, it could easily have been wiped out early on, perhaps never to evolve again.  Common sense also suggests that states-of-affairs will likely arise in the future that are incompatible with life as we know it today. 

So life then is suspended between ‘what is barely conceivable’ and ‘what is virtually certain’. It occupies the space between ‘not yet’ and ‘not still’. If so, then the bio-verse itself is a ‘logical dispensation’. It is a single fecund oasis perched above a giant sinkhole. It shouldn’t be…but it is!

We can say that life on Earth did evolve, and we must anticipate its eventual extinction, so the only variable here is the time span. Time span is quantifiable but like all quantities, it is comparative. Is a liter a lot or a little? Neither? Both? Once you understand the terms, the question itself makes no sense. 

What then is the comparison between time and no time? What is the significance of ‘one’ in a universe already known to span at least 60 orders of magnitude? About all we can say, objectively speaking, about any ‘time span’ is that it is neither instantaneous nor eternal. 

A grandson once referred to a now deceased friend of ours (appropriately called Big John) as ‘giant’. Was John a speck of dust (“All we are is dust in the wind” - Kansas) or the Colossus of Rhodes? Both!

Conditions on Earth vary. They vary by temperature and tempest, by the density and chemical composition of the atmosphere, and by the availability of water. Yet from the top of Mount Everest to the mouth of a thermal vent on the ocean floor, there is life. From arid desert to arctic glacier, there is life. ‘Give us any gas, we’ll breathe it’ – Laverne & Shirley.  O₂? It’s a breeze. CO₂? A-OK. Terrestrial life has even evolved organisms that breathe methane! 

Once evolved, life is amazingly durable and adaptable. The tenacity of its survival contrasts with the fragility of its birth. Can’t live without it, can’t live with it, can’t kill it!

The biosphere is omni-recursive. It gradually terraforms its physical environment to make it more bio-friendly: e.g. stone becomes soil. It experiments with innumerable distinct survival strategies, called species. Finally, it creates Artificial Realities (Culture, Society) that confer additional resilience via epigenetic adaptation. 

The existence of ‘life’ is extremely improbable but once here…it’s here to stay!

Hypothesis: The conditions necessary for the emergence of a living molecule are much more stringent than the conditions necessary for its survival. 

Once life happens, it’s almost impossible to snuff it out. Of course, individually, we’re all only one stray bullet away from the boneyard and even as a species, we face eventual extinction. But as far as life per se is concerned, we’re not sure what it would take to kill it off. 

Consider Pando, the largest organism (by mass) on Earth. (It’s a tree!) It is at least 15,000 years old but none of its constituent organs (trunks) lives more than a few hundred years. 

That said, the conditions on Earth 4 billion years ago were anything but bio-conducive: Heavy asteroid bombardments, high levels of radiation, zero oxygen, superabundant methane. It’s hard to imagine that conditions on Mars, even today, are any less propitious for the emergence of life than that.

Martian Bio-skeptics (that’s humans skeptical of life on Mars, not Martians skeptical of life on Earth) blame the planet’s sterility on its lack of heat, air, and water. But this argument is tired. We just flew 72 helicopter missions over the Martian surface. If the planet’s atmosphere is thick enough to support flight, it’s certainly sufficient to support some form of life.

Even today, conditions on Mars are probably sufficient to support biogenesis, but if not, they certainly were at some time in the past. From what we know about life, it should have emerged and evolved on Mars at more or less the same time it did on Earth. We’re looking for life on the moons of Jupiter and Saturn, and I hope we find it – in my lifetime, please; but isn’t it much more likely that life would have emerged on our twin planet?

Based on what we think we know about biogenesis, there should be life on Mars. If it turns out that there isn’t, somebody’s “got some ‘xplainin’ to do, Lucy”.

David Cowles is the founder and editor-in-chief of Aletheia Today Magazine. He lives with his family in Massachusetts where he studies and writes about philosophy, science, theology, and scripture. He can be reached at dtc@gc3incorporated.com.

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