In the July-August issue I talked about the mathematical form of basic laws of physics, inspired by Dirac’s suggestion that “God is a mathematician.” But I also said that we needn’t think God’s creative work to be based entirely on mathematics. “God is not a pinhead,” as I put it. There is no compelling reason to think that all properties of matter can be derived from fundamental laws of quantum theory and relativity. Derive as many facts about collections of H2O molecules as you wish but you’ll never get to the concept of wetness.
The limitations of a strictly mathematical approach become clear when we deal with complex systems, especially the complex phenomenon “life.” It is hard even to give a satisfactory definition of life, let alone a formula for it! It is not that biology has no use for mathematics — recall Mendel’s use of statistics to analyze the results of his experiments. Ian Stewart’s The Mathematics of Life (Basic, 2011) gives many other examples. But this doesn’t mean that all biology can be derived from mathematical physics.
Without further ado, I will move to the most important unresolved issue connected with life, its origin. This is important not only scientifically but also theologically.
When we speak of “the origin of life” we mean the development of the first living things from non-living materials. The terms “abiogenesis” and “chemical evolution” are also used. Today we have no satisfactory scientific understanding of how such development took place on Earth or might have taken place in other parts of the universe. We certainly do not know how to produce “life in a test tube.”
Claims that we’re close to understanding life’s origin and that only details remain to be worked out are sometimes heard.
One thinks of physicist Wolfgang Pauli’s response to a colleague’s claims. In an interview after he published a new theory, Werner Heisenberg said that it should explain everything about elementary particles, and only details were missing. In a letter, Pauli sketched a blank rectangle with the caption, “‘This is to show the world, that I can paint like Titian:’ Only technical details are missing.”1
Critics of biological evolution often zero in on the lack of an explanation for abiogenesis as a defect of evolutionary theory. But biological evolution is about how living things evolve, not how life originated from non-life. Scientists want an explanation of chemical evolution but that isn’t part of biological evolution.
Critics also argue that the idea of spontaneous generation was long ago discarded. Maggots won’t develop in rotting meat if flies do not lay eggs there. Scientists like Spallanzani and Pasteur showed that microscopic lifeforms would not develop in nutrient media if they were kept from outside contamination. The early chapters of Paul de Kruif’s classic2 are still worth reading on this.
Popular ideas about how some living things came into being were wrong, but Christian theology had no problem with the idea that life could arise from non-living material. That idea is built into Genesis 1. “Let the earth put forth vegetation” (v.11), “Let the waters bring forth swarms of living creatures” (v.20) and “Let the earth bring forth living creatures of every kind” (v.24). As some the church fathers realized, it is precisely of living thing things that the Genesis account speaks of mediated creation. God does not say, as with light in v.3, “Let there be vegetation” etc.
The Nicene Creed’s statement that God is “maker of heaven and earth, of all that is,” means that everything, living and non-living, has its ultimate origin in God and depends on God for its existence. If someone argues, “Only God can create life,” the proper Christian response is that in a fundamental sense only God can create anything. But there is no reason to think that God had to create life by immediate divine action, apart from natural processes.
A traditional way of speaking about God’s action in the world is to say God “cooperates” with creatures in their actions. That is what is meant when we say that God creates “mediately”. Natural processes have the regularity that successful science depends upon, so God apparently limits divine action to rational patterns that we can approximate with our “laws of nature”. The task of scientists is to understand the natural processes which God uses.
But the fact that theology is open to the origin of life from non-living material doesn’t prove that it happened that way. Even less does it tell us how, where and when it may have happened. What does science say about that?
In a letter to a friend, Darwin referred to the idea of life originating in “Some warm little pond”.3 But he didn’t think that enough was known then to develop a scientific explanation of the phenomenon. For about half a century little was accomplished in that direction.
In 1936 A.I. Oparin reviewed the history of ideas about life’s origin and made some significant proposals.4 He argued that simply building up more and more complex organic molecules would not lead to life, and suggested that the formation of colloids and aggregations of colloidal particles called coacervates could be initial stages of structures like those found in cells. He also emphasized the important role of enzymes, such as the proteins which in biological systems catalyze crucial reactions.
Similar ideas were presented by J.B.S. Haldane in England, who coined the phrase “prebiotic soup.” Both Oparin and Haldane sketched a scenario in which such a soup on a primitive earth with a reducing atmosphere could, with energy from lightning or ultraviolet radiation, give rise to compounds and structures needed for life.5
In 1952 Stanley Miller, a student of Nobel laureate Harold Urey, carried out an experiment to reproduce such a hypothetical scenario. Water with compounds that could be expected to be present on a primitive earth — molecular hydrogen, ammonia and methane — was boiled at low heat in a closed system so that a spark discharge, simulating lightning, could pass through the vapor. After a few days the water became discolored, and analysis showed the presence of some of the amino acids, building blocks of proteins.6
Many variations on this experiment have been performed, resulting in production of all the significant amino acids and other organic molecules. These experiments have been seen as a confirmation of the basic Oparin-Haldane theory. But some qualifications are needed.
While proteins are crucial, life also needs entities to carry and transmit the information required for reproduction and “descent with modification.” DNA was recognized as the genetic material and its structure was explained around the time that The Miller-Urey experiment was done. Later versions of the experiment have made the nucleotides that compose DNA and the related RNA molecule. Somehow appropriate proteins and nucleic acids have to develop together and be combined. This isn’t an insuperable “chicken and egg” problem, but it isn’t enough to say that it happens “somehow.”
There are also questions about whether the environments envisioned in this theory are right. Considering the emergence of life as a chemistry experiment, we have to be concerned about the type of retort in which it is carried out as well as the chemicals and the processes they’re subjected to.
Many alternatives to a “warm little pond” have been proposed. Amino acids have been found in meteorites, and might have been brought to earth by them. (That is not “panspermia,” the idea that life originated on another planet and drifted — or was sent! – to earth.) Discovery of “extremophiles” — bacteria living deep in the earth’s crust, in high temperature volcanic vents and even tanks of radioactive reactor waste — has suggested other possibilities.7
There are also questions about how much time a process leading to life would take. It would require vastly longer than the age of the universe for the smallest proteins to form just by amino acids randomly coming together in the right order. Something else clearly is needed.
So we need to know processes that might lead to emergence of life and environments in which they might take place. Let us consider two approaches that address those concerns and have recently received attention.
Physicist Jeremy England addresses the process question.8 He has developed a theory in which a flow of energy drives a collection of atoms to develop structures enabling it to dissipate energy to the surroundings more efficiently. That ability is typical of biological systems. Living things cannot remain in thermal equilibrium with their surroundings — “To assume room temperature” is a euphemism for dying!
Traditional thermodynamics, focused on ideal “reversible” processes (in which a system would always be in thermal equilibrium, and so such processes would take forever) can’t handle flows of energy and material at non-zero rates. While irreversible processes result in dissipation of energy and increased entropy and molecular disorder in the universe, they can also give rise to “dissipative structures”, like convection cells in a fluid. Nobel laureate Ilya Prigogine suggested that living things might be such structures.
More recent developments have made it possible for England to push this idea farther and consider systems very far from equilibrium. He argues that flows of energy through appropriate collections of atoms would make the emergence of live almost inevitable. Recent computer simulations of such systems have shown promising results in this direction.
Of course there is a big difference between computer simulations and what might happen with collections of real chemicals. And there are, as I mentioned, dissipative structures that are clearly not alive. What distinguishes living things from other complex systems brought into being and maintained by energy flows remains to be clarified.
The second approach addresses the question of the environment in which the necessary processes could have taken place.9 The oldest traces of life on earth, about 3.5 billion years old, are found in northwestern Australia. Studies suggest that billions of years ago this area had active geothermal fields with steaming pools and geysers, somewhat like Yellowstone. This suggests an interesting scenario.
Amino acids and other basic materials, perhaps some from space, could accumulate in heated pools and eventually concentrate in sacs of lipids which had formed. This would enable them, with energy available, to form more complex molecules. So far this is the warm little pond picture. But in this environment the ponds would go through cycles of dry, wet and moist gel conditions, with different processes taking place in each stage. There would be mixing of contents among numerous ponds and a kind of natural selection among the resulting products.
“After much trial and error, one protocell assembles the complicated molecular machinery that enables it to divide into daughter cells. This paves the way for the first living microbial colony.”10 Primitive lifeforms then spread, adapt, and colonize new areas.
The quotation in the last paragraph reminds me of the well-known Sidney Harris “Then a miracle occurs …” cartoon. But let’s hold off on the cynicism for awhile. This, like England’s approach, can be seen as part of a scientific research program. Neither one will provide a complete explanation of how life emerged on earth or a formula for life. But if we pursue both proposals we may see how a physics-based approach together with one appealing to empirical and geological and chemical investigation can explain the means which the Creator used to bring forth life on earth.
George Murphy received his Ph.D. in physics from Johns Hopkins for work on general relativity in 1972. He taught at Westminster College (PA), The University of Western Australia and Luther College and did research for eleven years before entering Wartburg seminary. Ordained in 1983, he has served as a pastor in Lutheran and Episcopal congregations. His first article on theology and science was published in 1977 and he has since published six books and numerous articles and continues to speak and lead workshops in this area. His most recent book, Models of Atonement: Speaking about Salvation in a Scientific World (Lutheran University Press, 2013), discusses ways of understanding the saving work of Christ in an evolving world.
- George Gamow, Thirty Years that Shook Physics (Doubleday, 1966), p.162. ↩
- Paul de Kruif, Microbe Hunters (Harcourt, Brace,1926). This is available in other editions and online. ↩
- https://www.darwinproject.ac.uk/letter/DCP-LETT-7471.xml. ↩
- A.I. Oparin, The Origin of Life (Moscow, 1936). An English translation published by Macmillan in 1942 was republished by Dover in 1953. ↩
- http://www.simsoup.info/Origin_Landmarks_Oparin_Haldane.html ↩
- Stanley L. Miller, “Production of Amino Acids under Possible Primitive Earth Conditions,” Science 117 (1953): 528. ↩
- See, e.g., Paul Davies, The Fifth Miracle (Simon & Schuster, 1999), which surveys origin of life possibilities two decades ago. ↩
- Natalie Wolchover, https://www.quantamagazine.org/a-new-thermodynamics-theory-of-the-origin-of-life-20140122/ and https://www.quantamagazine.org/a-new-thermodynamics-theory-of-the-origin-of-life-20140122/ . ↩
- Martin J. Van Kranendonk et al., “Life Springs,” Scientific American, August 2017, 28. ↩
- Van Kranendonk et al., p.33. ↩