Biological Fine-Tuning

© Sharlene Jackson, freeimages.com

It’s reasonably common to hear physicists and astronomers talk about ‘fine-tuning’, or the ‘anthropic principle’. The idea is that a large number of physical properties (such as the strength of gravity, or the forces within the atom) need to be at very, very precise values or life as we know it would not exist. The numbers are incredible – probabilities with more decimal places than there are atoms in the universe!

Is there any evidence of fine-tuning in biology? Biology is a much newer science than astronomy and the systems involved are far more complex, but even so, there are a few glimmerings of fine-tuning on the biological horizon. There has been a good deal of interest in Cambridge Palaeobiology Professor Simon Conway Morris’s research on convergent evolution. In his popular level book, ‘Life’s Solution: Inevitable Humans in a Lonely Universe’ (CUP, 2003), he describes how the course of evolution navigates towards fixed points in the total space of biological possibilities. This winding path towards higher levels of complexity, and ultimately intelligent life, is entirely consistent with the Christian belief in the purposeful sustaining of the universe by its Creator.

So has anyone else approached the subject of fine-tuning in biology, or is Conway Morris a lone voice? Theologian and biochemist Alister McGrath has spent time on this subject (see A Fine-Tuned Universe and a less technical reworking of similar material in Surprised by Meaning). The main point McGrath makes is that the biological world relies on the same fine-tuned physical and chemical properties that astronomers spend so much time discussing.  Without compounds such as carbon, oxygen, hydrogen and phosphorus, life simply wouldn’t exist.

McGrath also points to an interesting paper in the April 2003 issue of the International Journal of Astrobiology. In it, astronomers Bernard Carr (St Mary’s, London) and Martin Rees (Cambridge) give an account of a 2002 conference on biological aspects of the anthropic principle. Even in a conference with this title, issues of chemical evolution took up part of the proceedings, but what was most interesting was the section on ‘evolution of biological fine-tuning’. The research in this area was all too tentative to be published more fully, but covered areas such as robustness in biological networks, and the ‘choice’ of DNA and proteins as information carrying molecules in biological systems.

Biological systems are enormously complex, which is why it’s taken us so long to get around to even beginning to understand things at the level of whole organisms. But there is a trend, in that although the total ‘space’ of possibilities (for example, for the sequence of a protein of a particular length) is usually enormous, in reality the number of variants present in nature is relatively small. At times it is possible to pinpoint why certain solutions have been arrived at – for example, the camera eye is quite simply the best way to see light. At other times the reason why a particular solution has been arrived at is less clear, as in the origin of biochemical systems and cellular life.  Whether the existing systems we see are an accident of history (i.e. where a number of potential solutions could work) or are another example of fine-tuning, is yet to be determined. What is clear to me, however, is that the astonishingly fertile chemistry of life and evolvability that we see is entirely consistent with the existence of the God revealed in the Bible who provides us with a rich source of teaching and guides us though the process of learning by our mistakes.

Best Explanation in Science

Photo from Test of FAITH, © The Faraday Institute

I’ve been reading Alister McGrath’s book ‘Surprised by Meaning’, and I love the picture of the scientific enterprise created by the section entitled ‘The Best Explanation’ (chapter 6, page 26-17).

McGrath begins by explaining that the same data may give rise to multiple competing theories about the way things are. The challenge is to come up with the explanation that makes the most sense in the light of the data. The best explanation may not make sense of every piece of data or be completely confirmed by the evidence available, but it will make as much sense of as much of the data as possible when compared to other theories.

we have to ask how successful a theory is at making sense of the world, while we look over our shoulder at its rivals.

Towards the end of the section he questions the popular assumption that scientists huddle together until they find the most logical explanation for a phenomenon.

the ‘best’ explanation may not be the most reasonable or commonsense explanation. Scientists don’t lay down in advance what is reasonable. Time and time again, they have found the natural world to contradict what common sense might have expected or predicted. Science would fail if it were forced to conform to human ideas of rationality.

McGrath quotes quantum theory as evidence of the sometimes surprising nature of scientific discoveries. He goes on to say that

The instinctive question for the scientist to ask is not ‘is it reasonable?’ as if one knew beforehand the shape that rationality had to take, but ‘What makes you think that might be the case?’ Science is about warranted belief, not about rational belief. The history of science is about the recalibration of notions of ‘rationality’ in the light of what was actually discovered about the deeper structure of nature.

I find this testing of our assumptions appealing because it makes the world and our exploration of it so much more interesting. It takes all sorts to build a good lab, because you need the variety of perspectives that different personalities bring to the table. With a well-rounded research group you can examine the data in a number of ways, explore a variety of different avenues, and come up with great results. (Well that’s the theory anyway!)

In general I’m resistant to inferring the character of God from nature, but I will make an exception here. I do believe that the nature of the created order, in that it repeatedly challenges our assumptions, reflects something of God. We have to go beyond our gut reactions. Jesus is the perfect example: born into a poor family, breaking religious rules, honouring the rejects of society, making people think about their questions rather than giving a straight answer, rescuing us by dying a dishonourable death… The fact that God makes us think so much is the hardest part of being a Christian, but it ensures (at least some of the time) that we don’t slip into legalism or empty religiosity.

What is reality?

© Alex Nikada, istockphoto

I am reading two books side by side at the moment: Alister McGrath’s ‘Surprised by Meaning: Science, Faith and how we make sense of things’ (Westminster John Knox Press, 2011) and Richard Dawkins’ ‘The Magic of Reality: How we know what’s really true’ (Bantam Press, 2011).

In ‘Surprised by Meaning’, McGrath focuses on the search for meaning. Longing to make sense of everything we see and experience in the world is a basic human experience. It’s like the ultimate detective novel: how to make best sense of the clues? What’s the truth? I love this quote from McGrath, drawing on an image used by William Whewell.

We must find the right thread on which to string the pearls of our observations, so that they disclose their true pattern.

Dawkins on the other hand writes to convey his amazement and joy at the beauty of the world that science uncovers (a sentiment that McGrath has also expressed in his writing).

What I hope to show you in this book is that reality – the facts of the real world as understood through the methods of science – are magical in…the poetic sense, the good-to-be-alive sense.

Dawkins is also looking for answers. Where I part ways with him is his assessment of what constitutes reliable evidence. I wanted to read Dawkins latest book because I knew it would be a beautifully illustrated celebration of science. I always get so much from his imaginative analogies (the pile of photos analogy for human evolution is genius), and his writing style is something I want to learn from. I will try to pick out some quotes for another post in the future. Others have critiqued his understanding of philosophy and world religions. I do like this thought though:

That is the wonder and the joy of science: it goes on and on uncovering things. This doesn’t mean we should believe just anything that anybody might dream up: there are a million things we can imagine but which are highly unlikely to be real – fairies and hobgoblins, leprechauns and hippogriffs. We should always be open minded, but the only good reason to believe that something exists is if there is real evidence that it does.

I fully agree with this statement – great scientists possess the ability to make a courageously open minded assessment of all the evidence, and that should apply to beliefs as well as scientific data.