Every one and their great grandmother has apparently had a go at, and calculated a value for the Drake Equation (named after radio astronomer and SETI scientist Frank D. Drake). The Drake Equation estimates (guesstimates is actually more accurate) the number of extraterrestrial civilizations in our galaxy that could in theory say “Hi” to us and receive our “Hello” in return by examining all the factors that are part and parcel of that scenario. Seeing as how the Universe is some 13.7 billion years old, and seeing as how the current human species has been around for only some 200,000 years (give or take), then I have to ask, is it logical to assume that we’re the proverbial “It”? Here’s my two cents worth.
Are we alone in the Universe? That’s a question that’s been asked by millions over the eons, without, to date resolution. Of course the word ‘alone’ implies alone in the sense of whether or not there exists elsewhere our rough equals, more likely as not betters. We want to get to know our neighbours across the street, not their pets, or their plants. The standard gut-feeling answer to the question usually revolves around how vast the Universe is, and surely, given the billions of stars in our galaxy and the existence of billions of galaxies each with billions of stars, etc. and the vastness of time, surely we can’t be the proverbial “It”. There’s unfortunately one slight flaw in that statistical approach. There’s a rather long chain of events that have to happen, hurdles to be jumped, in order to get from the elements of star-stuff to biological cosmic neighbours. Depending on whom you talk to, that chain can be extremely long indeed. The point is, if any one factor in that chain of causality has a very low probability of coming to pass, it matters not one jot whether or not all the other factors are extremely probable, the overall result is going to be low. If any one factor is as close to zero as makes no odds, then the overall answer will also be a close to zero as makes no odds. Certainty multiplied by certainty multiplied by certainty multiplied by certainty multiplied by zero multiplied by certainty multiplied by certainty multiplied by certainty ultimately equals zero!
Rather than give an exhaustive list of all those factors required to give us cosmic neighbours, I’ll focus on six essentials.
Firstly, one has to have the right kinds of matter and energy that can produce beings like us, and a solid surface to stand on. That’s no problem. The Universe has lots of kinds of energy on tap; stars can manufacture and disperse the required kinds of matter, like carbon, nitrogen, oxygen, silicon, etc. There’s lots of solid bodies (planets) out there. That’s one vote for certainty.
Secondly, one has to have a solid planetary body turn into a habitable world; a suitable environment for physics, chemistry, biochemistry and biology to do their evolutionary thing. Fortunately, that shouldn’t be a problem. There’s a lot of real estate out there and it comes in all sizes and flavours. While there’s only ever going to be one Planet Earth (I’ll avoid discussions of the Many Worlds Interpretation of quantum physics, the notion of parallel worlds, and the Multiverse here which could argue the contrary), there has been, is, and will be, lots and lots of earth-like abodes, just letter perfect for life-as-we-know-it to survive, even thrive. If one wants to throw in life-not-as-we-know-it, there will be lots of worlds suitable for those possibilities as well. So, that’s another vote for certainty.
Thirdly, physics has to become chemistry, and chemistry has to become biology. We need biology to have had origins, or an origin, an origin(s) of life that’s an inevitable outcome of the everyday ordinary interactions between physics and chemistry. Well, many will argue that the origin of life is as nearly predictable as death and taxes, given a suitable habitat. Many will also argue that the origin of life is a fluke! In my point of view, the origin of life need only happen once, and that clearly has been a certainty – we exist and we are life. Once there’s one origin of life, the rest is just distribution. Panspermia provides the ways and means of distributing (microbial) life throughout the cosmos. So, I’ll have to cast another vote for certainty again!
Fourthly – well, now we hit the proverbial brick wall. You and your neighbours aren’t microbes – you’re a colony of microbes. In short, you’re a multicellular life form. We seek, in the cosmos, other multicellular life forms, on the grounds that the odds that a microbe or unicellular life form isn’t going to prove to be much of a companion or drinking buddy is a near given. So, we need to get from unicellular to multicellular, and therein lays the rub. And it’s here that we have to rely for guidance on a sample of one – Earth. Note: It’s dangerous to extrapolate from a sample of one, but what choice do we have?
There’s no ecological niche on Earth occupied by multicellular critters that’s not also occupied by unicellular critters (microbes). The reverse isn’t true. You may think the world is totally dominated by multicellular critters – you, your partner, your family, your pets, your garden, your food, all the life you see around you is multicellular. There’s millions of species of insects – all multicellular. What’s more common than bugs? Yet, if you did a biological census, even in your home and your garden, you’d find that apparently common multicellular life forms are out-common-ed, vastly outnumbered, by unicellular life forms by a ratio of trillions to one. What you don’t see does matter!
So, are multicellular critters an evolutionary certainty? Is there anything a ‘colony’ of 2 or 20 or 200 or 2000 cells can accomplish or fill a previously unfilled ecological niche that one cell can’t? And by the way, that 2 or 20 or 200 or 2000 stage has got to be selected for before one can get to the two million and two billion colony stage. Well, clearly the transition happened here, albeit it took some three billion years to seriously kick-start the process, so it’s hardly some inevitable ‘law of nature’. I mean taking some three billion years to get to a colony of cells from a single cell doesn’t inspire confidence that the process is easy, necessary or inevitable. Anyway, it did happen here, so it’s obviously possible. I just don’t see it as a super-evolutionary development that confers immediate survival-of-the-fittest advantage. Of course a colony of two cells might be harder to eat than one cell, but at that level, ‘food’ tends to be absorbed at the molecular level. In any event, microbes can easily attack and ‘eat’ multicellular critters, causing sickness, death and decay. We’re ultimately food for the microbes and the proof of that pudding is how we spend small fortunes keeping them at bay. But, eventually, though you might win the battles against the microbes, you’ll lose the last one, and thus the war.
Another factor that argues against multicellular organisms being a universally common feature of the Universe is that it is also a lot harder to transport around the Universe by natural means – that concept of panspermia – multicellular critters. I mean getting a microbe from Earth to Mars is one thing. Getting a cockroach there is a whole different scenario.
Multicellular development; its probability, can’t be zero since we’re multicellular, but, on balance, I can’t assign a high probability to the transition between unicellular and multicellular life on every habitable planet, every time. This one is nearing zero!
Fifthly, as noted earlier, you don’t want to interact with your neighbour’s multicellular pets or multicellular garden plants, but your neighbours. What do you have in common with your neighbours that you don’t have in common with your neighbour’s pet or garden plants? Intelligence (even if you probably think your neighbours are a few cents short of a dollar!).
The issue now is whether, having evolved to a multicellular stage, will one develop some higher brain function? Is there any further evolutionary advantage towards increasing one’s intelligence? By going back to our sample of one, if Earth is any guide, the answer is roughly ‘not likely’. There are millions of multicellular species that have existed, and do exist, on Planet Earth. There are apparently only a very few species that have evolved something beyond the minimum level of brain power required for their day-to-day survival. That doesn’t inspire confidence that intelligence has inevitable value as a means of survival.
By far and away, most multicellular critters just operate on pure instinct and don’t (can’t) stop to figure things out (far less stop to smell and appreciate the roses) - but, there are an admittedly few exceptions. Many wild birds would put our everyday companion animals to shame in the IQ department. I mean I love my cats, but little Einstein’s they’re not. Whales and dolphins have also been credited with being in the higher IQ bracket; ditto our close primate cousins. In the invertebrate kingdom, the octopus is pretty smart – by invertebrate standards (and then some if one is honest). However, on balance, most multicellular critters put their evolutionary strategies into something other than higher brain function. Take my cats. Is it to their survival advantage to ‘figure things out’ or to be just a bit faster afoot, hear just a bit better, see ever more clearly? Nearly all organisms put their survival abilities into something other than pure brain-power. Clearly brain-power has survival-of-the-fittest attributes. But, it’s not the only game in town, and therefore doesn’t have what I’d call evolutionary ‘certainty’. However, it would be illogical to say that developing intelligence, the ability to figure things out, isn’t valuable and doesn’t have survival value; it’s just that if you were to list all the multicellular animal species on Planet Earth, very few would have an IQ of even one (the human average is 100). So, let’s say intelligence is somewhere between certainty and highly improbable.
To be continued...
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