Over the last two essays, I’ve explored what Genesis teaches and how that’s relevant to science, and whether it is possible that evolution could have been guided by God. If you’ve taken in what I’ve said, you might be at the point where you’re willing to grant that Genesis 1 is a nice story, regal and reserved in comparison to popular creation myths from the ancient near East. Maybe, you may say, we can squint at the text and jimmy it to fit, to minimize the glaring cognitive dissonance. But, at the end of the day, many will believe it’s still an outdated creation myth, irrelevant in the light of modern science. In response, in this essay I’ll briefly review some findings of science which have given at least some who believe in an unintended universe pause for thought.
We live in a universe bursting with purpose. This is particularly evident in biology, but purpose spills over throughout the scientific disciplines. The big picture story of the universe appears to be one of increasing complexity, at least in many interesting patches of the universe. This is made possible by a stunningly low initial entropy. Sir Roger Penrose, PhD supervisor of Stephen Hawking, has argued that the initial conditions at the beginning of time and space must have been set to 1 part in 10^10^123 out of the total phase space, to account for a universe as we currently see it and compatible with the second law of thermodynamics (this amount of fine tuning was not required for life per se, however, but various other parameters do require substantial specificity). This is of course an absurdly tiny proportion.
Fundamental Fine Tuning
There are various other examples of fine tuning in physics, which are relevant to the existence of carbon-based life, and quite widely discussed. One example is the ability of stars to produce significant quantities of both carbon and oxygen, due to the ‘Hoyle resonance’ named after famed atheist cosmologist Fred Hoyle, which appears to depend on fine tuning of fundamental parameters such as the force between nucleons (p. 41). I’ll leave the details, which are certainly important, to the physicists. Also worth looking into for the physics-minded are fine-tuning for discoverability, and some remarkable properties of our planet.
Getting closer to biology, the fundamentals of biochemistry appear very well set up for life as we know it. For instance, the properties of water, oxygen, and carbon-based compounds interrelate in remarkable ways, as explained in Michael Denton’s detailed and under-appreciated book “Nature’s Destiny”, and summarised in this essay. One of my favourite examples is the bicarbonate ion – that the waste product of metabolism (carbon dioxide) dissolves in water, the matrix of life, to form an ideal buffer system is remarkable, but just one part of a much grander system. Denton’s ambitious claim is not just that biochemistry supports the case for fine-tuning, but that it focuses it more on us. He suggests that life as found on Earth, rather than life in general, is what the universe appears to be particularly finely tuned for.
Something I would like to see more work on is the properties of transition metals; which ones are essential for complex life, and whether additional physical fine tuning (something like the Hoyle resonance, for instance) is required for them to exist. Various transition metals are required for fundamental biological processes such as photosynthesis, nitrogen fixation, and oxygen binding. I think such fundamental ‘biochemical’ lines of enquiry deserve further attention, but overall the idea that the universe is remarkably well set up for life has already received quite a bit of discussion. More controversially, can the principle of ‘fine tuning’ be applied to biology itself? And can we pursue this line of thinking without rejecting mainstream evolutionary science?
Finding Teleology in Evolution
Natural selection has been widely believed to remove any sense in appealing to God as an explanation of teleology in biology. While this is an area needing much more work, I’m not convinced by the standard story that Darwinian evolution removes the possibility of finding evidence of genuine purpose in biology. One of Darwin’s famous early supporters, Thomas Huxley, agreed with me on this, saying, “Nevertheless, it is necessary to remember that there is a wider teleology which is not touched by the doctrine of Evolution, but is actually based upon the fundamental proposition of Evolution.” The context for Huxley’s views is discussed much more in Alister McGrath’s excellent book.
How to bring this insight into the 21st century though? Some of the background for developing such an argument is provided by Rope Kojonen e.g. in this paper and David Glass – e..g this video, from around 30mins. Dr. Glass argues that evolutionary explanations do not necessarily explain away the evidence of purpose in biology. Here I expand on this by sketching some biological details which seem to me to support something like the idea of fine tuning.
Fine Tuning in Biological ‘Initial Conditions’
In cosmological fine tuning, there is commonly a distinction made between fine tuning of initial conditions and fine tuning of parameters. It may not be a hard and fast rule – it’s not obvious for instance which category the fine tuning of the cosmological constant fits into – but it’s a useful rough categorisation. I’d like to propose a similar distinction for biology – there is evidence for fine tuning in initial conditions and the fundamental parameters of evolution. By fine tuning I just mean that it appears that if conditions were slightly different, life as we know it would likely not exist, or at least would have been hindered in its development. Please note carefully that I’m not presenting an argument for divine intervention in life’s history – what I say is, as far as I can tell, compatible with everything discussed here being the result of lawlike natural processes – it’s just highly unexpected if there’s no mind at all behind the universe.
As an example of initial conditions, let’s consider the initiation of biology – the origin of life. There are various elements here which I think could be mined productively. The general idea that life’s origin was somehow unexpected, and the conditions involved highly improbable, seems to be quite widely recognised. A leading theorist even made an appeal to the multiverse as an important part of the explanation for life’s origin on Earth. More specifically though, let’s quickly look at the standard genetic code, which is generally believed to have been a later development – arising sometime between life’s actual origin and the last universal common ancestor of all life we’ve come across so far (LUCA). The code is simply the mapping between nucleotide triplets (e.g. ATG) and amino acids (e.g. Methionine) or the ‘stop translation’ signal.
There are huge numbers of possible codes, in at least two respects. Firstly, and seldom discussed, the code could conceivably encode a very different set of amino acids. Surprisingly, most such sets would not do nearly as good a job as the set we have does. When 100 million conceivably possible combinations of 1913 amino acids which might’ve been present on the early Earth were considered in a study published in Scientific Reports in 2015, the set which our code uses was found to be among the top few in terms of the distribution of chemical properties. Those which were better than the standard code in three properties considered were all more energetically expensive to produce. The standard genetic code is approximately as good as 1/108 sets in these properties. To me this seems excessive over expectations.
But wait, there’s more! The positions of the different amino acids in relation to the nucleotides could also be very different. There isn’t space here to explain this much, but the arrangement of the nucleotide triplets (codons) has a few remarkable properties. Of most relevance to our focus here, the standard genetic code appears to be beneficial for Darwinian evolution, as explored in a few papers. It’s also, and most famously, optimised for error minimization (a closely related property), for encoding short messages in parallel to proteins, and perhaps also for encoding overlapping genes.
Fine Tuning in the Evolutionary Parameters
It’s not just the beginning of life or the last universal common ancestor that has the interesting property of parameter sensitivity – changes appear to lead to a reduction in optimality, if not outright destruction. The whole evolutionary process only works because it can traverse a deep set of networks. The shape of these networks is what I mean by ‘evolutionary parameters’. There are a few of these networks. The relationship between the sequences and structures of RNA molecules, for instance, or the mapping between protein sequences and functions, or between biochemical functions and evolutionary fitness. We don’t yet know a lot about how constrained these mappings would have to be to allow for evolution to produce life as we know it – but in at least a few cases there is evidence that they need to be quite a special subset of the total number of possibilities.
The total space of possible proteins is huge – hyper-astronomical. There is good, but controversial, evidence that this space is sparsely populated with function overall. Attempts to create functional proteins from random sequence libraries have shown that in most cases, the sequence space must be restricted in some way in order to make progress in finding functional sequences. As one review put it, “Randomly generated sequences, … rarely fold into well‐ordered protein-like structures. To enhance the quality of a library, features of rational design must be used to focus sequence diversity into those regions of sequence space that are most likely to yield folded structures.” It appears to me that something similar must have been true for evolution – the sequence space searched must have been limited. Complex enzymatic functions requiring a stable protein fold are particularly hard to find through random searches of the whole sequence space.
Some have used this as an argument against evolution even being possible. There is a lot that we don’t know, however, about the mapping between protein sequence and function, and searches of random sequence libraries for function have not been entirely unsuccessful. The frequent origin of new genes, the history of which can be traced through sequence comparisons, also undermines this line of argument against evolution. At this point in time, it seems reasonable to me to think that life’s history, while it unfolded through evolutionary processes, has been constrained to a small part of the sequence space and that the map has been particularly, unexpectedly, favourable in the small part which life has traversed. In a nutshell, it looks like evolution happened, but that we were very lucky that it was able to go the way it did.
My interpretation is that we really are living on the edge of chaos. Life, while remarkably robust in the current context, in the grander scheme of things is delicately poised. A nice analogy is cellular automata such as John Conway’s game of life, discussed in an important recent book on fine tuning (pp. 231-234). There are many different possible rules which can govern these systems – but overall it appears that very few of them are able to sustain complex and stable structures. Life in the real world is such a remarkable phenomenon that its origin has been suggested by leading theorist Paul Davies to perhaps require new physical laws.
Such a situation is I think not surprising for the theist who believes the universe to be the product of a rational mind, a mind which is particularly interested in living beings and community. There is significant room for further teleological reflection in this direction, within the empirical boundaries discovered by cutting-edge mainstream science. There is good reason to be excited about natural theology – the heavens declare the glory of God; molecular biology proclaims the work of his hands.
A Fortunate Universe – Luke Barnes & Geraint Lewis
Nature’s Destiny – Michael Denton
Life’s Solution – Simon Conway Morris
Arrival of the Fittest: How Nature Innovates – Andreas Wagner
(Does not advocate fine tuning, but serves as a great introduction to the biological foundations which allow for evolution)