The origin of life is not a supernatural event. It may be an event whose cause we cannot even discover or draw a conclusion about. Or one whose explanation our methods are certain to miss. We often hear rhetoric along the lines of “The methods of science can solve the origin of life puzzle!” But science is not a magic wand. We may be seeking information that is irretrievably lost. We may be asking meaningless questions, due to a conflict between our underlying assumptions and reality. More insidiously, we may be satisfied with an answer that meets the demands of an underlying belief system while missing the nature of the reality. Life fascinates us. Recently, a consortium of research institutions paid $840,000 for two lbs. of meteorite ore in which they hoped to find traces of a crash landing from outer space — one that started life on Earth.
This electron microscope image is a close-up of the center part of photo number S96-12301. While the exact nature of these tube-like structures is not known, one interpretation is that they may be microscopic fossils of primitive, bacteria-like organisms that may have lived on Mars more than 3.6 billion years ago. A two-year investigation by a NASA research team found organic molecules, mineral features characteristic of biological activity and possible microscopic fossils such
as these inside of an ancient Martian rock that fell to Earth as a meteorite. The largest possible fossils are less than 1/100th the diameter of a human hair in size while most are ten times smaller. And these were INSIDE a rock that they cracked open, that they think came from Mars somehow, someway.
Yet, curiously, as a special edition of Astrobiology (2011) admitted, “Biologists have been unable to agree on a definition” of life.” NASA took the lead by defining life as “a self-sustained chemical system capable of undergoing Darwinian evolution.”* When chemist Harry Lonsdale offered $50,000 in 2011 for the best explanation of the origin of life on Earth, he adopted that definition. As an atheist, he made his ultimate goal clear: “The world will learn that the laws of chemistry and physics, and the principle of evolution by natural selection, are sufficient to explain life’s origin.” But the years have not been kind to NASA’s definition. It identifies only one trait, which may not even be universal.
For example, life’s simplest cells often evolve by swapping genes, not through Darwinian evolution. The definition of life has reached the point where science historian George Dyson tells us, “Life is whatever you define it to be.” Richard Dawkins has suggested it is “anything highly statistically improbable, but in a particular direction.” And at a year 2000 international “What is life?” conference, no two definitions were the same. Biochemist Edward Trifonov noted that there are 123 definitions available and, undeterred, promptly proposed his own: Life is self-reproduction with variations. Which was just as promptly contested. In a 2012 issue of philosophy journal Synthèse, Edouard Machery concluded that “scientists, philosophers, and ethicists should discard the project of defining life.” Still in the game, astrobiologist Charley Lineweaver proposes a new, non-Darwinian approach to defining life: Many biologists define life as anything that undergoes Darwinian evolution … We pretend that makes sense, but if you look it makes no sense at all. What is the unit of Darwinian evolution? Is it the gene? Is it the cell? Is it a multicellular organism? Is a city evolving? Is that a life form?
Similarly, evolutionary biologist Bjørn Østman asks, Suppose we go to another planet and find one being there, looking exactly like a human being. Everything we can measure about this being confirms that it is just as much alive as you and me. It eats, moves, heals, replenishes, communicates, feels, defecates. Learning more about this being, though, we find that it has no ancestors, and that it does not age. It does not reproduce, and it is the only such being on the planet. Thus, there is no lineage of descent and no population that can evolve. So this being is then not alive? Of course it is. This definition does not work. Come to think of it, he wonders, if R2D2 from Star Wars existed, would he be alive? More provocatively still, in Scientific American, Ferris Jabr ends up concluding that life is just a continuum from non-life and doesn’t really exist as a separate category. If we could see the underlying reality of our planet, we would see … the innumerable atoms that make up everything on the planet continually congregate and disassemble themselves, creating a ceaselessly shifting kaleidoscope of matter. Some of those flocks of particles would be what we have named mountains, oceans and clouds; others trees, fish and birds. The trouble is, we know better. So 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, favoring 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. Some origin-of-life theorists respond by making Darwin’s natural selection into an intelligent agent, the precise opposite of his intention. Stephen J. Freeland of the NASA Astrobiology Institute attributes the fact that
“life knew exactly what it was doing” to — natural selection. He
tells us, ” … life seemingly did not choose its twenty building blocks
randomly.” Indeed, “We found that chance alone would be extremely unlikely to pick a set of amino acids that outperforms life’s choice.” When materialism governs science, that extreme unlikelihood can mean only one thing: There must be a law.
Some theorists hold that life is produced by a yet undiscovered law of nature. But, unlike other laws of nature, where we have some idea how they work even before we have a succinct statement of the law, we have no idea what this law could be. So, not surprisingly, the law-approach — while immensely attractive in principle — remains a minority choice because it offers so little direction. What about a chance origin of life? In this view, life is an unrepeatable confluence of accidental events
It might be helpful to think of the origin of life in terms of probability. Probability can be represented as a scale from 0 to 1. Events at 0 cannot happen and events at 1 must happen. For an event that has not happened, we face all the gradations of probability in between. The past is different. Event 0 did not happen but Event 1 did. Life is Event 1. However, the probability of life coming into existence by any of the specific series of sub-events currently envisioned (never mind demonstrated) is at or near Event 0. This is not an easy problem. At this point, assuming we still think the origin of life searchable, we can adopt one of the two permitted naturalist approaches: The law approach outlined above starts with Event 1 and delves into the fundamentals of physics and chemistry, hoping to find something basic and comprehensive. But it is far from obvious where we should look. Alternatively, we can join the partisans of chance. We can construct scenarios involving lucky spews from undersea volcanoes or random encounters with rare elements. Chance theories of the origin of life generate almost unlimited creative ideas compared to law-based ones. The world of ideas near 0 is densely populated
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.
University of Chicago cell biologist James Shapiro offers a different, conceptually more attractive approach, a 21st-century theory of evolution as he terms it. He proposes that life forms can in fact organize themselves. He writes: “Living cells and organisms are cognitive (sentient) entities that act and interact purposefully to ensure survival, growth, and proliferation. They possess corresponding sensory, communication, information-processing, and decision making capabilities …”
But can one properly use terms like “cognitive” or “purposefully” apart from demonstrated intelligence? And how does he think living cells and organisms began to exhibit such qualities?
Self-organization theory in general is fuzzy on how a life form gains the intelligence to organize itself. One of the best-known theorists, Stuart Kauffman, has described his work as “alchemy,” a term that famously resists specifics. David H. Koch, wealthy chemist and funder of TV evolution documentaries, tries to help by explaining, “It’s a deeper approach to understanding evolution. They’re not kooky ideas. The concept of self-assembly, for instance, where you put certain chemicals into a beaker or test tube, shake it up and vesicles form.”
At times, it happens. Last October, one group of researchers reported that fatty chemicals formed a primitive version of a cell membrane and “got the chemicals close enough to react in a highly specific manner: “Computer calculations reveal that even by chance, five liposomes in 1,000 could not have trapped all 83 molecules of the assembly. Their calculated probability for even one such liposome to form is essentially zero.” So, they concluded, “self-assembly into simple cells may be an inevitable physical process.”
Now that’s a leap of faith!
The good news is, self-organization might play a role in life forms if some of the great physicists are right: Mind or intelligence, or at worst information, underlie the universe, not matter. As John Wheeler expressed the idea: “It from bit.” In that case, perhaps we can discover laws by which information “self-assembles” into life. But they would be laws of information, not of physics or chemistry.
And those do not seem to be the laws that origin-of-life theorists want to discover. Admitting that there is no general consensus on what life is, the Chemical Reviews survey article nonetheless declares that it is clear that “all the current biodiversity is the outcome of Darwinian evolution from a primitive cellular species.” Darwinian evolution is, famously, blind. Similarly, Richard Egel et al. tell us that their book, Origins of Life: The Primal Self-Organization (2011), “distances itself from any intelligent design/creationist approach.” If the authors are so sure that blind processes drive the subsequent history of life, it is no wonder that they are thought to drive the prior self-organization too. That confidence has survived nearly a century of research whose main discovery is a host of inventive phrases describing dead ends.