Is there a good reason to believe that life’s origin must be a fully natural event? Note: The Science Fictions – cosmology series is here. The human evolution series is here. The Science Fictions: the human mind series is here.
The first clue about the adventure that we are in for is: Life is a state, an experience, that everyone has and thinks they can recognize in other people and things. A quality we think is very important. Yet no one can define it.
Darwin proposed a mechanism for the evolution of existing life — natural selection acting on random mutation — but, a prudent man, he stopped well short of proposing to account for life’s origin. Some of his followers pressed ahead. They ask us to imagine “self-replicating entities,” protocells, and “prebiotic life” (essentially, pre-life) that somehow evolved their way to life long ago. At New Scientist, Michael Marshall assures us,
Once the first self-replicating entities appeared, natural selection kicked in, favouring any offspring with variations that made them better at replicating themselves. Soon the first simple cells appeared. The rest is prehistory.
It must be prehistory. No such chains, protocells, or pre-life are found in a wild state today. And even the fabled “minimal cell” is more complex than expected. More.
Does nature just “naturally” produce life?
Essentially, law theorists assert that a chance origin of life is hopelessly improbable. Therefore, they assume, matter simply forms itself into life at some point, obedient to a law of its nature. The theorists do not at present have any idea what factors underlie such a law or how it has worked. Or why it is not working now, so far as we know (in the sense that new types of life are not self-assembling around us). They know that the law exists because life exists, chance is powerless to create it, and devotion to the philosophy of naturalism rules out design. More.
Apart from that, we know nothing at present.
Can all the numbers for life’s origin just happen to fall into place?
A chance origin of life offers a practical advantage:
Precisely because life is so complex, a great many ideas can be researched. And the field is still at the starting gate. When Harvard chemist George Whitesides received the coveted Priestley medal in 2007, he said, “Most chemists believe, as do I, that life emerged spontaneously from mixtures of molecules in the prebiotic Earth. How? I have no idea.” He did know what he thought of the cell, however:
The cell is a bag — a bag containing smaller bags and helpfully organizing spaghetti — filled with a Jell-O of reacting chemicals and somehow able to replicate itself.
The secret is in that “helpfully organizing spaghetti.”
Although chance-based proposals are far more numerous, they face the same key hurdles as law-based ones, including: More.
Welcome to “RNA world,” the five-star hotel of origin-of-life theories
When a cell divides, its DNA’s operational instructions are copied by RNA (ribonucleic acid), which directs the proteins that build cell machinery. The current leading origin of life hypothesis, RNA world (or RNA first) offers a limited and researchable claim, first proposed in 1967 by Carl Woese, Leslie Orgel, and Francis Crick: that RNA preceded and stood in for DNA in ancient life. Because this route slightly reduces the awesome complexity, it was not only too good to be false, it was hailed by key researchers as “the molecular biologist’s dream.” By 1986, biochemist (and Nobelist) Walter Gilbert envisioned a whole RNA “world” and Leslie Orgel was almost certain it had existed.
Not everyone was or is “almost certain.” Gustavo Caetano-Anollés is convinced of the opposite because “That world of nucleic acids could not have existed if not tethered to proteins.” A. G. Cairns-Smith, admittedly a champion of a rival “clay origin” theory, labeled it “absurd to imagine,” complaining that there are “14 major chemical/molecular hurdles” against more primitive nucleotides like RNA. New York University chemist Robert Shapiro (1935-2011) compared the theory’s likelihood to “a gorilla composing, in English, a coherent recipe for the preparation of chili con carne” and pleaded for greater realism. Yes, RNA theorists admit, there are difficulties. More.
Self-organization: Can we wring information from matter — shake the bit out of the it?
Irritatingly, self-assembly does sometimes happen. But the way it happens is no help. In 2009, one type of “Lazarus” bacterium, accustomed to extreme conditions, astonished researchers (who referred to such processes as “miracles”) by reconstituting itself within hours of its DNA being shattered by desiccation and radiation. The sample organisms proceeded to live normally. Clearly, the bacterium re-self-organizes, so to speak, guided by something that survives the destruction of its DNA.
But have we any reason to believe that this extra layer of interior guidance is an “inevitable physical process”? Far from it, the bacterium had to already exist in a specific form in order to self-reassemble. So it points to new levels of the specified complexity inherent in the life processes for whose origin we cannot account even without such a capacity. More.
Origin of life: Could it all have come together in one very special place?
Assuming that comets brought life to Earth, some ask whether it could have started on Mars. Steven Benner, chemist at the Westheimer Institute for Science and Technology, pursues this lead because, he admits, the chances of life forming on Earth are poor:
The molecules that combined to form genetic material are far more complex than the primordial “pre-biotic” soup of organic (carbon-based) chemicals thought to have existed on the Earth more than three billion years ago, and RNA (ribonucleic acid) is thought to have been the first of them to appear.
Simply adding energy such as heat or light to the more basic organic molecules in the “soup” does not generate RNA. Instead, it generates tar.
Generally, the public learns about problems like these when a radically new research emphasis is proposed. More.
Maybe if we throw enough models at the origin of life… some of them will stick?
Numerous less publicized models wallop through the science press, on the hope, perhaps, of a lucky strike: For example, not-obviously-promising substances such as hydrogen, ammonia, hydrogen cyanide, formaldehyde, or peptides, possibly kick started life. Maybe metals acted as catalysts. Or mica sheets. Otherwise, cold temperatures or ice helped life get started, despite the fact that cold reduces chemical reaction speed. Or a high salt environment. Or hot springs. No surprise that science writer Colin Barras observes that origin of life is “a highly polarised field of research.” Most fields have only two poles, not twenty. More.
Can we solve the mystery of the origin of life by creating life in the lab?
And — some may think this benefit alone worth all the trouble, risk, and expense — we could ignore dozens of sketchy model-of-the-month scenarios based on contested claims about Earth’s history. Either a model creates life or it isn’t ready for prime time. Science journals can then dispense with complex conditional tenses like “might have had,” “could have had,” and “would have had” when writing about the creation of life.
In short, the lab approach offers an all-science-and-no-religion way out of the present quagmire, with the likelihood of at least some useful answers. Why not just generally adopt it, or at least work toward it? One problem is that it doesn’t support claims about the vast powers of randomness or the brute laws of nature. And no solution that dismisses both can be regarded as “science” today. So origin-of-life projects continue to head off in dozens of directions to nowhere instead.More.
So, what really drives origin-of-life research?
Whether a field is considered “science” or “pseudoscience” now often depends principally on its relationship to naturalist ideology, not on whether it advances our understanding. What exactly have speculations about the multiverse contributed to science, for example? Today, in fact, evidence-based and reality-based thinking are seen not as tools or guides but as obstacles to the quest to make the multiverse real, at least in our minds — possibly the only place it ever can be real.
Origin-of-life research provides another classic illustration. Our survey of the field has turned up crowds of conflicting theories churning a largely disputed fact base. Crowds of conflicting theories is a bad sign in itself; when a science is advancing our knowledge, disagreements becomes sharper perhaps, but narrower. OOL research offers occasional new understandings here and there — and so did the practice of alchemy. That is because, happily, we can often learn something even when on the wrong track. But until we are on the right track, we cannot develop a large, organized program of evidence-based knowledge.
Sometimes, we refuse to admit we are on the wrong track because of a heavy emotional investment. Just such an investment drives current OOL research: the need to disprove design. As cosmologist Paul Davies explains, more.
With Enceladus the toast of the solar system, here’s a wrap-up of the origin-of-life problem
Creating life might be possible in principle but impossible in practice, if the technical difficulties are permanently out of our reach. We would have to try it to see. Even if we fail in our ultimate goal, we will learn a great deal more than we are learning from present approaches. In Engineering and the Ultimate (2014), [Arminius] Mignea tackles this very question by providing engineering specifications for the necessary components, functions, processes, and information of a simplest self-replicator (SSR): …
Mignea thinks that human technology does not yet have the level of sophistication, autonomy, self-sufficiency, and complexity of the simplest single-celled organisms (p. 217). But strikingly absent from his discussion are those staples of current OOL research, “would have,” “could have,” “may have,” and “might have,” which are, essentially, naturalistic woo. And not at all missed. In short, in order to discuss origins of life in a science-based way, we must begin by acknowledging the fact that intelligence is an inextricable part of the account. Then we will at least have a chance at making progress. More.
The Science Fictions series at your fingertips (cosmology) is here. The Science Fictions: human evolution series is here. The Science Fictions: the human mind series is here.
Note: World’s “oldest microfossils” are probably not life forms after all, according to just-published research. So billions of years of Darwinian evolution apparently did not happen.
– O’Leary for News