(continued) Chapter 3. Long Evolution: Life Emerging
What might the first life have been like?
We have spoken of “first life” – something unknown which somehow “became alive” (method also unknown) and thereby distinguished itself from everything else on earth which was, at that time, “not alive.” But maybe that’s not how it happened at all. Who among us can say they were standing there watching, or claim they know what happened? And if perchance God made it out of mud, as some believe, nobody was standing there watching that event either. You really have to wonder how so many people, with either scientific or religious mindsets, can be so cocksure of what they think they know.
In his wonderful little book Evolution in Action, Julian Huxley notes that self-reproducing life “appears to be linked with complex chemical molecules, in which nucleic acid is combined with a protein,” and that many other enzymes and carbohydrates must be present. While true, his words concern a much higher order of complexity than must have defined that first molecular life, however it began. Since we cannot know (and shall in fact never know) what the first life was like, speculations really ought to begin with the lowest level of complexity we can reasonably address with any assurance that we know what we’re talking about – atoms. (And we will speculate – on the stock market; pork belly futures; who’s bedding with whom – perhaps speculation should be considered one of the defining characteristics of life at the human level of complexity.)
Atoms represent a low but significant level of complexity, since several even “lower” forms of energy (quarks, protons, neutrons, electrons) must organize themselves in order for a “higher” atom to emerge from the chaos. Those lower components first appeared in the earliest instants (zillionths of a second) after the big bang explosion. They joined together meaningfully only after rapid cooling of the bang’s expanding plasma permitted them to self organize as atoms. And isn’t it interesting that though atoms are organized and have some complexity, they do not reproduce themselves, thus we can reasonably assume atoms are not “alive” according to our criteria above.
When two or more atoms bind to each other by sharing one or more electrons, they become a “molecule.” This moves us up to a slightly higher level of complexity. Since a molecule consists of at least two bound atoms, and sometimes rather quite a bunch of bound atoms, it inherently is more complex than any single atom. Examples of simple molecules are water, wherein two atoms of the element hydrogen are bound with one atom of the element oxygen (H2O), and table salt, a simple bond of one atom of the element sodium with one atom of the element chlorine (NaCl). It takes quite a few trillions of salt molecules, which you can’t see, to fill your salt shaker, but it can be done.
The various compounded molecules which comprise the bodies of living entities, such as algae and humans, tend to be quite complex in terms of sheer number of compounds per se and the quantity of different elements those compounds represent. To view examples, use your favorite search engine to call up a visual model of a sugar molecule, or search on “complex molecules” generally. Other examples include the DNA of humans and fruit flies, as well as the lipids and hydrocarbons that abound in the bodies of these creatures.
If a molecule is part of a living thing, it is called “organic” (even if such “organism” lacks organs, and some do). Many of the organic molecules that comprise living bodies contain atoms of the element carbon, and so carbon compounds are known to be integrally associated with life as we know it. When astronomers find planets circling distant stars, as they increasingly do these days, spectroscopic analysis soon follows to see if carbon compounds can be detected in any atmospheric gases that might surround the planet. If carbon is there, life might also be there. Many scientists are driven (by their life force) to try to find out if life might be there. Why are they so driven to attain this particular knowledge concerning life – not altogether unlike the way they are driven to reproduce? …help others; attain knowledge…
If a molecule is part of something not alive, such as a sand grain or a crystal, it is called “inorganic.” Interestingly, some of these inorganic molecules somehow, all on their own, also become more complex over time. But they are not alive. Examples of these too are easily found online. What, in the long-range scheme of things, do you think their increasing complexity might be self organizing toward?
An interesting never-never land exists on the fuzzy border between inorganic (non-living) and organic (living) compounds where reside the complex molecules we call viruses. They may or may not be alive – probably not, but we really don’t know. In general, a virus is as much smaller than a germ as a germ is smaller than you, and yet it has noticeable complexity. Most viruses are so utterly tiny that they exist down at the just-above-atom level of molecules, and that is in fact what they are. Viruses of all sizes are all complex molecules – which in turn consist of bunches of atoms bound together.
Viruses don’t exactly exhibit the criteria we’ve used to define “alive,” but they don’t exactly not exhibit them either. They obviously have capacity to organize. Whether they have any slightest glimmer of consciousness is anybody’s guess, but they presumably fit somewhere at the gradient’s bottom end. When viruses reproduce they certainly do so exponentially, but they lack their own built-in capacity to reproduce – a seeming paradox.
Viruses get around the paradox by being the ultimate parasites. By various means they invade a host, such as us, and then raid the cells of their host to obtain the living materials (amino acids, lipids, etc) they must have in order to reproduce. In other words, a virus must combine itself with some of your cells before it can reproduce enough of itself to harm you. Unable to generate or store energy (lacking natural food throughput), viruses steal the energy and metabolic processes they require from the cells they invade. Even if they were definitively alive, viruses could not be classed as plant, animal or bacteria – yet by one means or another they can invade and parasitize all of these. Viruses might have begun as rogue segments of our own genetic DNA or RNA that evolutionarily adapted to exist parasitically (some people and other creatures do, you know), but that scientific speculation is unlikely ever to be confirmed one way or the other. Parasitism seems to be built into nature’s options for enabling life, for we observe it in rampantly parasitic organisms such as mistletoe, corporate chiefs, lesser con artists and vile tapeworms.
Viruses muddy the water – and prey on people and other creatures of whom they kill millions every year. They certainly display that “urge” to survive and reproduce which persists so exponentially in all living things. But if they can’t reproduce on their own, without a host, are they really alive? An unambiguous definition of “life” – “living” – “alive” – will not be clearly established unless and until we understand viruses better than we do now. We are left with no choice but to be agnostic on the question – we cannot at present know whether viruses are “alive.” As with many other uncertainties, agnosticism is often the only completely honest posture, the only true admission that “I don’t know.”
Few people understand how muddy that water is, for there is considerably more to the virus story. Over recent years word has spread about the importance of bacteria that live on and in us – the human “biome” – especially in our intestines. It is gradually becoming understood that all these many species of bacteria, symbiotically processing the food we eat, are vital to our health and wellbeing – though many have not yet understood that taking “anti”-biotics kills the good guys along with the bad guys and is guaranteed to foul up their regularity. Even less well known is the fact that viruses play a similar role.
Known collectively as the human “virome,” in any given human body viruses outnumber both bacteria and human cells ten to one. They are ubiquitous in and on us as an integral part of our human bodies and biology. In our togetherness with viruses, we may be thought of as walking ecologies of diversity more complex than rainforests. While some viruses cause AIDS, flu and certain cancers, others promote our health. Research has actually shown that some of them are integrally part of our defensive immune system, some even controlling certain activities of the bacteria within us. And, just like gut bacteria biomes, no two persons’ gut viromes are exactly alike. Virome research, now in its infancy, will come to have much importance for understanding human health.
Some suspect that the RNA “organelle” within each modern human cell may even be an evolved remnant of ancient virus-like organic molecules. In many ways viruses let us know that, for better or worse, they have a natural affinity for co-mingling with the cells that make up our human bodies. We cannot discount the possibility that such affinity may be a holdover from those most ancient days when, on one particular day, a complex inorganic molecule underwent some kind of chance transition that enabled it to reproduce itself. Then, having become “organic,” it did it again, and again, with more than one self-copy in each succeeding generation – what we humans would someday call “alive.”
How and where did life evolve on earth?
The true story of long evolution, first a universe and then life within it, represents grandeur on such incomparably vast scale as to be worthy of nothing less than a creator god. The reality of evolution’s clever and mighty workings exceeds by uncountable orders of magnitude any fictional story we puny mortals might try to invent to account for it all.
Thus we stand meekly before unfathomable majesty. To “believe” the ancient primitive Genesis version – with unquestioning “faith as of a little child” – one unavoidably must also believe that Omnipotent, Omniscient, Omnipresent God went to the trouble of creating all those trillions of suggestive fossils, large and small, then deliberately strew them around out there in the top few miles of the earth’s crust for the sole purpose of deceiving us gullible small children into thinking the earth might be more than six thousand (6,000) years old. And why not? – God can do anything, right?
Anybody so gullible as that could probably be duped into thinking heavier-than-air helicopters with no wings can be made to fly. We concede that Genesis leaves much to be willfully ignored. He, God, created moraines and great lakes so we would be misled into thinking they were left by receding glaciers as they melted 12,000 (12,000) years ago. Ever deceptive, He took the time during his seven busy earth-length days to bury a large meteoroid on the coast of Yucatan so that we, childish minds that we are, would think its impact killed the mythical dinosaurs whose apparent bones He created and buried for us to find and, finding them, could use our silly carbon dating machines to erroneously conclude it was a whopping 65 million years ago that the meteoroid killed the dinosaurs.
Deception – by God. Think about that. Maybe it’s a Godly test to see if we deserve to be arbitrarily struck dead for the arrogance of using our rational thinking minds – which, recall, are among God’s many images – the rational minds which God himself built into us when He created us directly from mud during those famous six days of whatever length days were in those days. It seemingly is a situation not unlike that of Eve and the infamous apple of knowledge, isn’t it? – an apple a day, as they say. …help others; attain knowledge…
Please, are there any other options that might graduate us simple Children of God beyond kindergarten fairytale land to some real land where the Laws of Nature and the Word of God don’t arrive as divinely handwritten pages floating, wafting, magically down from Heaven up there, somewhere, above the upper layer of waters God separated on high?
Life may have originated when lightning struck warm soupy water, perhaps at the shallow edges of earth’s early seas. In 1871 Charles Darwin wrote in a letter to his friend Joseph Hooker that life on earth may have begun in “a warm little pond, with all sorts of ammonia and phosphoric salts, lights, heat, electricity, etc. present, so that a protein compound was chemically formed ready to undergo still more complex changes.”
Darwin’s conjectures, like his evolutionary theories, were highly credible. In 1952 graduate student Stanley Miller and his professor, Harold Urey, conducted a now-famous experiment showing that organic molecules actually could have formed, spontaneously and naturally as Darwin speculated, from inorganic materials and conditions present on the early earth. After a week of sending electric sparks through an inorganic mixture of water, ammonia, methane and hydrogen, up to 15 percent of the carbon enclosed within the experiment was transformed into organic compounds. These significantly included five amino acids, which are the building blocks of proteins at the foundation of life. More recent re-analysis of the experiment’s products identified 23 amino acids, signifying that Miller and Urey were more successful than they realized.
A sophisticated modern variation on the same theme occurred in 2010 when a team of scientists at the J. Craig Venter Institute extracted genetic code from the DNA of a bacterium, mycoplasma genitalium, and inserted it into a second bacterial species. The result was a hybrid lifeform that reproduces itself – the first human-generated lifeform with an artificially synthesized genome. They named it Synthia, though science refers to it as mycoplasma “laboratorium.” The unusual project tampered with life but it did not “create” life, nor does it begin to explain the natural process by which that first complex molecule reproduced and became “alive” as we define life. But it certainly is playing around the threshold of a newly opened door.
People are stepping through such doors. Harvard biologist Jack Szostak led a team that in 2013 showed that common citrate, a cousin of citric acid found in limes and lemons, enables the hereditary RNA molecule to copy itself. “Our goal,” he says, “is finding some reasonable and continuous pathway from small molecules up to more complicated building blocks, then to cells that can start to evolve.” If scientists keep on in this manner they may actually hit on a believable scenario as to how life originated on planet Earth. But – here several billion years later – no one will ever be absolutely sure.
Always look for the third option. Having only two often results in bipolar disputations, especially where churchmen and scientists are the principal disputants. On the origin of life, let it be noted that only science has proposed options which may be called credible, whereas religion’s options differ with every different religion, including Old Turtle. On the other hand, there obviously is no reason, no reason at all, for scientists to feel smug.
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…to be continued in one week…
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