The Truth about Science and Religion. Fraser Fleming
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system (nucleolus). Efforts to mimic simple cells have identified reactions that can be performed inside cell walls, although these are controlled by the inherent reactivity of the chemicals rather than by a central cognitive system. Complementing this build-it-yourself strategy is the construction of artificial cells by inserting a minimal set of enzymes, nucleic acids, and cell metabolites to bring the cell to life. Simple processing by strings of RNA is possible but a great divide exists between simple chemical reactions and a cell capable of the three defining characteristics; metabolism, self-reproduction, and evolution. At the heart of the dilemma is the paradox of life: the cell components, the membrane proteins, RNA, and DNA are all interdependent. The cell wall and membrane encapsulate these key molecules in a safe environment which in turn requires proteins, DNA, and RNA for their synthesis. How cells became self-replicating is one of the most incomprehensible processes in biology.
An enormous gulf exists between simple and artificial cells and the simplest cellular organism. Genetic experiments aimed at determining how many genes are required in the simplest cell indicate that about 250 genes are minimally required for cell function. For a simple bacterium the genome consists of around 106 nucleotides, representing one DNA sequence out of a possible 102.4 million. The chance of randomly forming the genome is vanishingly small. Once the construction of the first living cell through synthetic assembly is achieved, if the endeavor is even possible, this will only provide a shadowy, though monumental, contribution to understanding the origin of life.
Perhaps the most striking aspect of the evolution of life on the earth is that it happened so fast. Scientists have suggested that life may be almost as old as the earth with an origin that may have virtually coincided with the birth of the planet. As an example, the population of organic walled microstructures from the Swaziland System, South Africa, found in 1977, was identified as the morphological remains of primitive prokaryotes. The rocks were dated as 3.4 billion years old, relatively close to the age of earth at 4.5 billion years. Despite dramatic advances in molecular biology, there is still no agreement in how life first began. Where and how life began is one of science’s great mysteries. Guesses range from life being a spectacularly successful accident to being the expected outcome of a universe primed for life.
Living cells are the most complex small systems in the universe. Specialized molecules work in concert, seamlessly conveying messages to ensure that the cell performs exactly the right function within the living organism. Most perplexing is the lack of an intelligent agent controlling the cell; life is sustained and replicated by individual organisms themselves. How the first single-celled organisms came into being is a puzzle which science has been trying to unravel. At the root of the problem is a philosophical issue: from where did life’s instructed complexity come? Organisms literally have a life of their own.
Information has to come from somewhere. DNA is full of information for protein synthesis, some of which forms the machinery to make and repair DNA. Random mutation can give rise to new sequences of potential information, requiring some screening process to weed out the beneficial mutations. That screening process is again another information source. Where did all the information come from in the beginning, and how did the protein-DNA symbiosis come into being? DNA is the cell’s software which delivers the message for protein synthesis on the cell’s main-frame. The origin of this information-rich system is currently unknown. Perhaps the information was primed into the universe from the beginning, although how this was done remains highly speculative.
The classic view of life’s origin is through a series of key events, each building on prior levels of complexity. Empty vesicles, like oil droplets, encapsulated primitive biomolecules whose chemistry powered the cell’s energy needs. During the progressive development, the enzymatic production of DNA was adopted, improved, and became an intimate part of cellular programming. The origin of many key steps in the development of life is as yet unidentified. Some argue that science will eventually be able to discover exactly how self-replicating, complex organisms first came into being. Others argue that life is too complex to understand completely and that while dramatic advances will continue, understanding life’s origin will always be elusive. Both are philosophical speculations.
Conclusion
The origin of life requires what currently appears to be a remarkable series of coincidences. Living organisms require a series of building blocks of ever increasing size: amino acids, proteins, nucleotides, DNA, and genes. Once in place, these key cellular components must coalesce to form single-celled organisms that subsequently diverge to produce plants, animals, and ultimately the human race. Every key biological development requires a remarkable level of complexity that increases as the precursors are incorporated within ever larger structures.
Interpreting the results of origin-of-life experiments is complicated by the practical limitations of reproducing conditions of early earth on a grand scale—no one wants a Big Bang in their back yard. Complicating the analysis of these intriguing experiments is identifying the origin of the information required to assemble complex biomolecules. Purely random events generate diversity that requires a sorting mechanism to retain the information present in the new molecular entities. At the current time the sorting mechanism is unknown and the rapid emergence of life so soon after earth became habitable remains an enigma.
Science has been remarkably successful in discovering how life works; for example, the discovery of DNA, mapping of the human genome, and cloning. Discovering the origin of life would make all prior Nobel Prize discoveries pale in comparison. However, from a philosophical perspective, there is no reason to believe that science should be able to discover the origin of life, nor, even if science discovered the origins of biological organisms, would this answer the philosophical questions this book raises. The driving force to search for answers to such difficult questions as the origin of life is largely because of science’s proven ability to discover new knowledge in the past and the likelihood that future benefits will accrue regardless of whether the original question is answered.
Prebiotic experiments demonstrate a remarkable synthesis of life’s building blocks despite gaps in current origin-of-life theory. For some, the experiments provide a compelling explanation for the spontaneous formation of life on earth while others believe such chance occurrences require some type of divine guidance. In the past, people have suggested specific developmental interventions, formation of the eye in particular. Time has harshly treated these God-of-the-gaps arguments. More recently, God’s input has been identified more within the unfolding of life on earth: God as the grand designer who continuously acts to bring the world into being. For religious people who experience God’s intervention in their lives, the question naturally arises as to why God would not similarly intervene in creation. The God of Genesis stresses the relationship of people to God as the key to understanding life. The figures of speech describing God’s attributes in human terms: making and speaking, conveying God as being personal and knowable, set the stage for an intimate relationship. God’s “hovering over the waters”29 makes his presence difficult to detect, and yet is consistent with God’s invitation to search for him in the world, leaving the interpretation of the evidence up to each individual.
Discussion Questions
1. The creation story in Genesis has often been interpreted as a literal six-day creation with the aim of creating men and women in relationship with God. How would the relationship between people and God be different if God were to create humans by a slow evolutionary process?
2. Is the idea of God consistent with an evolutionary process based on chance, waste, and suffering?
3. When a rose is picked from a rosebush, at what point is the rose “living” and “dead”?
4. A person who has just died leaves a body that no longer has life. What is the difference between the lifeless body and the virtually identical living person who inhabited the body just a few seconds or hours earlier? Is there a difference?
5. One proposal to explain the formation of high-energy biomolecules in the absence of cellular machinery is by a “frozen accident.” The idea is that an accidental occurrence generates a molecule that somehow becomes codified into the living process. What is the difference between the scientific postulate of a frozen accident and a religious assertion of divine intervention in the evolutionary process?
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