In his latest book Origin the popular American thriller author Dan Brown ventures once again far out into the realm of scientific speculation. This time he deals with the question about the origin of life on earth. Brown seems unwilling to settle for less. In the usual far-fetched manner his plots evolves around his protagonist […]
In his latest book Origin the popular American thriller author Dan Brown ventures once again far out into the realm of scientific speculation. This time he deals with the question about the origin of life on earth. Brown seems unwilling to settle for less. In the usual far-fetched manner his plots evolves around his protagonist Robert Langdon hunting after a profound secret of his murdered friend, a computer genius, who has sensationally uncovered a seemingly indisputable explanation of how life on our planet started. But Brown goes further than just dealing with one existential question: the murdered protagonist Edmond Kirsch also claims to have found how life on Earth will continue to evolve in the next few years. For this purpose, Brown lets his protagonist Kirsch succeed before all others – including Google, Microsoft and IBM – in building a quantum computer as well as creating an autonomous artificial intelligence. With the help of his computational superiority, Kirsch managed to simulate the origin of life from the primeval soup and thus to calculate the temporal development of the Miller-Urey experiment for many millions of years.
As he does in all his books, Brown intermingles scientifically accepted insights and actual current technological developments (the Miller-Urey experiment, the current efforts in quantum computers and artificial intelligence) with speculative extrapolation and outright nonsense. However, he does know how to portray this mixture so shockingly that some readers surely wonder how realistic the scenario set out in Origin actually is? Some light on this question is necessary, which Dan Brown, of course, does not deliver. Regarding the question, how the earthly life originated, this shall be done here. The questions about the possibility of quantum computers and artificial intelligence, however exciting these may be, have to be examined elsewhere.
What is life? – An old question from the point of view of the modern natural science
The problems already begin with the question of what life is after all. The lexical definition according to Wikipedia is “living organisms are organized units that are, among other things, capable of metabolism, reproduction, irritability, growth and evolution.” The carrier of information in these processes are biomolecules, the most important of which are deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Thus, living beings are self-replicating systems whose structure and performance are safeguarded over long periods of time and for many generations. On the other hand, due to the inaccuracy of the replication, there exists the possibility for evolutionary adaptation to environmental changes, which in the long term allows an evolution of the Darwinian type.
Today’s biology regards the transition from the inorganic to the organic world as continuous. This is the reason why it cannot provide a complete and final definition of life. This inability, however, by no means contradicts its naturalistic program. On the contrary, by definition a complete, and thus excluding definition would presuppose a discontinuity between non-living entities and life. This discontinuity would have to be based on something which cannot be traced back to physics or chemistry. The biologists’ claim for the possibility of a complete physico-biochemical explanation of life presupposes that the constitutive components of a definition of life cannot be formed on the basis of clear distinctions and irreducible concepts. In fact, a unique, complete, and precise definition of life stands in direct contradiction to the naturalistic research program.
Can life be built on scratch?
“Any stupid boy can crush a beetle. But all professors in the world cannot make one”, wrote Arthur Schopenhauer in the nineteenth century, thereby requesting respect for the uniqueness of life. The fully artificial synthesis of a living organism would surely be the decisive turning point in the discussion about the nature and origin of life.
As Dan Brown correctly points out, in 1953 Stanley Miller and Harold Clayton Urey performed the first and most famous scientific experiment to simulate the origin of earthly life. They showed that under conditions like the ones our planet was exposed to about 4 billion years ago (CO2-rich atmosphere, acidic oceans, intense lightning) after a rather short amount of time simple amino acids arise naturally. In the solution. After some longer period of observation more complex amino acids developed as well. At last the amino acids produced corresponded exactly to the 20 amino acids that we find in living organisms today. Despite this amazing observation, the details of the development from simple building blocks to cells and more complex forms of life with metabolism, self-reproduction, and evolution remain unclear to this day. Here, Brown builds a fictitious bridge that is anything but well supported by the state of our current scientific knowledge by making his protagonist simply calculate the underlying chemical processes in the Urey Miller experiment with the help of a computer simulation, and this in every single detail and all the way to today (and beyond). This is, to say the least, blunt nonsense: Even a powerful quantum computer could never exactly simulate the complex initial and boundary conditions in the primeval soup from 3.6 billion years ago all the way to the dynamics of today’s global society.
It is indisputable that for an explanation of life and its origin, alongside evolution we need the second block of modern biology as well: genetics. Almost 15 years ago biologists cracked the genetic code of man, that is, they determined which combination of DNA building blocks encode which amino acids and how the amino acids then form the many different proteins in our body. This does not mean, however, that we know everything about our genetic constitution. On the one hand, we do not know what precise purpose particular proteins are synthesized for, i. e. how individual proteins and protein combinations are related to specific body functions. On the other hand, the interaction between genes and protein synthesis is extremely complex and has so far been understood only to a minimal degree. Furthermore, many aspects of the process of protein folding, i.e. how proteins are brought into their three-dimensional structure, are not yet clear to the biologists. Here, a quantum computer might indeed help quite a bit.
Emergence of life – The core problem of all possible beginnings
The metabolism of the first life forms consisted essentially of preparing organic substances from water and atmospheric carbon dioxide. In simple terms, the basic synthesis of life was to bring hydrogen and carbon dioxide – substances which the atmosphere of the early earth directly or indirectly provided in excess, but which normally do not react with each other – into a more complex chemical compound. Together with nitrogen (from the ammonia present in the atmosphere), sulfur and phosphorus compounds (which had reached the surface of the earth through volcanic activity) and certain metal compounds (abundantly present in the oceans), this made a well-seasoned cocktail for the development of life.
As Urey and Miller illustrated, under such conditions different elementary organic hydrocarbon compounds – the first “molecules of life” – actually do form. Most likely, the next step towards life was then the collision (the so-called “polymerization”) of these first biomolecules (the so-called “monomers”) into chain-like macromolecules. This could have only happened with the help of external sources of energy, which were abundantly provided by solar radiation, volcanoes, radioactivity, or chemical processes. Since the syntax of the genetic code is the same for every living being on Earth, the biologists find it more than plausible that these early processes had to be the same for all forms of life on earth, from the simplest bacteria to humans. And there were indeed places where the conditions for the formation of the first molecules of life were as good as perfect: volcanic springs in the deep sea (so-called “black smokers”). Here, many biologists suggest, the “chemical gardens” developed in which the chemical reactions took place that produced the first more complex organic molecules that lead to of life, among them those macromolecules which still play an essential role in the metabolic reactions within all life.
However, the early life forms had to solve two fundamental problems. First, for the processes running inside their “bodies” such as growth and replication, they required a steady external supply of energy, as for physical reasons there can be no such “metabolism” without energy. A living organism, in order to maintain its orderly state, must compensate for the physically unavoidable increase in entropy inside its body by external energy. Brown’s starkly shortened depiction that “entropy simply means that energy is distributed as widely as possible” is way too simple. Such oversimplification can easily be categorized as “nonsense”. Secondly, the early forms of life had to be able to reproduce themselves. While energy was sufficiently available, replication proved to be much more difficult. In all of today’s life responsible for the storage of vital information as well as for their dissemination to future generations are the DNA and RNA. Thus, in order to get to an answer to the question on the origin of life we have to understand how the first polymers of RNA and DNA formed from carbohydrates and amino acids. A complex information carrier such as the RNA can hardly have originated by pure coincidence.
This get us to the most important issue concerning a naturalistic explanation of life’s appearance of on earth. In order for the development of a Darwinian evolution to occur at the molecular level and functional forms of life to develop, criteria for the natural selection of molecules was needed, in which “improved” molecules replaced “less optimal” ones (such a process of natural selection and evolution on the level of molecules Darwin already considered possible). Such a process presupposes a priori standards for “adeptness” and “viability” of a molecule. In other words, some sort of “biological information” was already needed, and correspondingly a genetic code. Only such a genetic code, however primitive it might have been, allowed the molecules to store the information necessary for further development and selection, and at the same time to be the carrier of evolutionary changes. A classical “chicken or egg” problem!
Darwinism versus Creationism – The actual question that remains
An important missing link in the exploration of the origins of life and thus to a complete scientific explanation of life is therefore the origin of biological information. How can information and meaning have arisen from a completely information-free environment, i.e. a world governed solely by chance? Its origin resembles the “creatio ex nihilo” at the origin of the cosmos – only here we deal not with energy or matter, but with information. The starting materials for the first RNA monomers (nucleotides) or short polymers as well as the necessary energy for their production were surely sufficiently available in the archaic ocean. Phosphates were present in the hot springs, the sugar ribose and other organic compounds could have formed in the “primordial soup” from the carbon dioxide-hydrogen compounds. But individual RNA molecules contain as little genetic information as a single letter provides a meaningful statement. To this core problem on life’s origin the biologists can still not give an answer. The vague reference to entropy, dissipative structures or emergence, as Brown has his protagonist provide, falls far too short. So here too, at this crucial point, Brown has nothing serious to offer except unfounded, dodgy speculation and unsubstantiated fog.
Thus the 150-year-long struggle between creationism and evolutionism should no longer revolve around the question of whether man and all animals and plants were once created in their present form by an external intelligence of whatever kind. Today, no informed person can seriously hold on to this view. All creatures on earth are the result of an evolution that originated about 3.5 billion years ago. But disputes are quite appropriate when biologists argue that the genetic information arose suddenly and completely accidental in the form of a first self-replicating RNA or a preform of such, from which life developed through evolution towards its current form. The probability of such an event is close enough to zero that we can easily disregard it.
And all too much time (about 250 million years) was surely not available between the point at which complex macromolecules were first able to “survive” (that is, they did not disintegrate immediately due to the adverse conditions on earth) to the earliest (bacterial) forms of life, the oldest of which we see in today’s fossils. This cannot have been an a priori all too improbable process. Another reason why the development of the first forms of life must have occurred much faster than possible by mere statistical fluctuations. Representatives of religious movements refer at this point to a divine act of creation. Naturally, scientists reject such a non-verifiable “ad hoc hypothesis”. But until the exact origin of life is clarified and possibly reproduced in the laboratory, it will hardly be possible to completely disprove such religious descriptions by means of the scientific method.
But even if the exact and real-historical processes are still unknown, today’s molecular biology shows that the early development of life on the basis of purely biological mechanisms is principally possible. For meanwhile there are quite plausible scientific explanations for the transition from inanimate matter into living systems. A natural origin of life could have taken place quite in accordance with the known laws of physics and chemistry, thus the origin of life is likely to be interpretable naturalistically. The basis of this assessment are developments in the physics of the second half of the 20th century, which deal with the description and modeling of “complex self-organizing systems”.
The most promising way to explain the important formation of information in the very first forms of life are models of selective self-organization with catalytic support within a primordial soup of inanimate molecular building blocks, as sketched by Manfred Eigen and Ilya Prigogine in the 1970s and 1980s. Yet even the most primitive forms of life represent complex inter-acting systems in which the functions of the individual components, whether molecules or cells, can no longer be understood intrinsically as separate independent units. The components are no longer isolated entities, but can only be understood “contextually” or “relationally”, i.e. in relation to the entire system as well as the concrete environmental conditions. Thus the real-historical development of very early life depends on many specific boundary conditions and parameters, which can hardly be captured and represented in a model. We are thus confronted with similar epistemological and methodological problems as with the hypothesis of life having been formed randomly.
This is precisely where the central criticism with respect to Brown’s story arises: We do not know enough about the initial and boundary conditions to simulate the process of the origin on a computer as it has actually taken place, let alone to calculate how the state of our present civilization has been reached from there and will develop further. Even a quantum computer cannot perform this task. Here, Brown tampers with the myth quantum computers (assuming none of his readers understands those anyways) to create an unrealistic and senseless scenario. At best, we can simulate scenarios how life might have originated in its early stages.
The reference to spontaneous order through emergence and self-organization, however, falls also principally short of dealing with of our problem here. The question is not how complex order evolved out of simpler structures (which in many cases is relatively easy to explain), but how information is generated. An ink stain (pure random) or turbulent flows (with a highly non-linear dynamics) are highly complex, but not specified, i.e. without any information. On the other hand, ink-written text is highly specified, that is with information (as well as complex). While we trace the ink splotch back to a random process or a very complex dynamics, which can systematically, i.e. mathematically assessed, the text written with the ink requires for its creation some sort of intelligent design. Once again, what requires explanation is not the origin of a complex order, but the origin of the information.
Thus even the most prominent anti-creationist and atheist Richard Dawkins, despite all his verbal (and partly overly polemical) argumentation, cannot get rid of this problem and does therefore himself not have a clear and definitive answer to the question “design (god) or coincidence (nature)”. Has the scientific method reached its limits here? Is any combination of chance (arbitrariness) and necessity (natural laws and circumstances) ever capable of explaining the origin of information-rich biological complexity?
Contextuality – Life and its environment
With quantum physics physicists were forced to abandon the classical idea of independent (atomic) substances. Not individual independent substances such as atoms represent the fundamental stage of reality in our world, but the permanent interactions these constituents are exposed to and from which they cannot be isolated. Can it surprise us that when it comes to the question of life’s origins we are confronted with the same feature of reality? Although each cell is a structurally defined, self-contained and self-sustaining system, the characteristics of a living being can by no means be understood on the mere basis of irreducible individual cells. Without its external surrounding, i. the context in which it lives, such as nutrient environment, pH value, other cells, etc. the properties and behavior of a single cell remain largely undefined. As genetic researchers know today, this is true even on levels below the cell. For ultimately DNA cannot be understood solely on its own ground. Biologists can now determine external, i.e. non-DNA-encoded factors that control the activity of individual genes. In other, more scientific, terms: The phenotype is also affected by external factors beyond straightforward genetic expression that are not explicitly determined by the genotype. These are (often even hereditary) changes in the genome function which, in addition to those directly acting by the gene sequences expressed within the DNA, have their origin mostly in environmental influences the living being has been exposed to. The biologists speak of “epigenetics”.
Epigenetic functionalities show what psychologists, educators, and sociologists have long argued for: Living beings are much more than the sole expressions of the specific gene sequence of their genotypes, but obtain their properties, abilities, and possibilities also by interaction with the environment in which they live. A concept that (next to “emergence”) is often referred to in this context and which originated in the discussion of the confusing qualities of quantum physics is “contextuality”.
This adds an interesting new dimension to the long debate between reductionist (considering only the components of a system) and holistic (considering only the total system as a whole) currents of thought in the discussion about the essence and origin of life. The reductionism suggested by biologists such as Craig Venter, according to which life and its origin can be explained solely by a description and combination of the individual components and their corresponding historical evolution, finds its methodological limitations. Biologists are able to find general naturalistic explanations about how life could have come about, but we must recognize that due to our lack of knowledge about the exact environmental parameters, that is, the geological, chemical and biological boundary conditions we must assume a fundamental uncertainty with regard to the concrete and real-historical processes around how life actually started, until we know in detail the primeval circumstances on Earth some 4 billion years ago. For, unlike in physics, where they are contingent, i.e. cannot be derived from theory, in the biology of the origin of life boundaries conditions are at the center of a potent theory. In other words, the specific circumstances and initial conditions under which life arose are essential for a consistent biological theory.
God and the origin of life
Looking at the personal convictions of today’s biologists, we recognize that when it comes to the question about the beginning of life most of them have turned their back on God and religion. However, this does not mean that the characteristics of individual creatures or the development of a complex organism from a single fertilized egg does not appear as miraculous also to biologists. The exactly coordinated organs and functional units of living creatures, their always astonishingly purposeful and directed behavior, and their almost perfect adaptation to the external circumstances are deeply amazing and awe-inspiring.
This leads many to the belief that there is a higher intention to life, a planning entity that must have thought of all this. The (long-held) notion that nature as a whole possesses a deeper meaning and progresses intentionally, i.e. towards ever higher levels, has been thoroughly shaken up by modern biology. The biologists find absolutely no evidence and no reasonable argument for the assumption that evolution aspires to any goal or manifests a meaning. The famous evolutionary biologist Ernst Mayr formulates this as follows.
There is neither a program nor a law that can explain and predict biological evolution in any teleological manner. Nor is there, since 1859, any need for a teleological explanation: The Darwinian mechanism of natural selection with its chance aspects and constraints is fully sufficient.
But this does not help us to get to the heart of the question about life’s origin, either. We recognize where the true open problem of a naturalistic approach to this question lies: All attempts to find a clear and unambiguous explanation for the origin of biological information have so far failed.
This failure causes a few biologists to look in the opposite direction. “In the beginning was the word” in the prologue to the Gospel of John turns into “In the beginning was the information”. The future discussion between natural sciences and faith should begin at this point. This unfortunately gets lost on Dan Brown’s readers.
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