The claim of biblical theism is that the world in which we find ourselves is not eternally self-sufficient: it has a maker, on whom it depends not just for some initial impulse long ago, but for its daily continuance now.
This is strange language to modern ears. The world we know seems very stable, reasonably law-abiding (in the non-human domain at least) and not at all obviously in need of any divine power to keep it going. Over the past 200 years and more, we have become accustomed to thinking of it as a mechanism, intricate perhaps beyond the grasp of human understanding, but still something self-running and self-contained. Continue reading →
Studying the origin of life is an intractable problem, a little like navigating the misty trackless waste that is central Dartmoor. For an event that happened so long ago, we are unlikely to find a ‘smoking gun’. If life originated on another planet and then somehow seeded life on Earth – a possibility that is being taken seriously at the moment – we have even less hope of finding a solution.
This was Christopher Southgate’s impression of the field of origins research until a few years ago. Chris is a theologian and former biochemist based at Exeter University, and in his Faraday seminar on New Approaches to the Origin of life: Scientific and Theological last week, he explained why he is now a little a more hopeful. He also described a very unique research programme that combines both science and theology.
Life is generally easier to describe than define. Any description that tries to be all-inclusive will inevitably leave something out. Southgate’s own definition includes three properties: Continue reading →
Incredibly, every living thing – you, your cat, the plant on your desk, and the bacteria in your toilet – share exactly the same genetic code. It has been suggested that the particular code we all use was arrived at by chance, and that we have a shared genetics because we have a shared ancestor. Others think while it’s true that we have a common ancestor, our molecular biology is highly optimised.
The genetic code is fascinating because it links two completely unrelated biological systems. It’s rather like sending a message in Morse code and receiving it with a machine that uses binary numbers. The two codes are completely unrelated, but it’s possible to translate between them. It sounds odd, but this juxtaposition of completely different systems works incredibly well in living organisms. Continue reading →
The Faraday Institute summer course is in full swing, and on Tuesday morning evolutionary biologist David Lahti presented some reflections about his own work on human behaviour. What he said was fascinating, and raises all sorts of questions regarding human personhood. The analogy that he used was the baking of bread. The ingredients he focused on were the ‘flour’ of genetics, the ‘water’ of the environment, the ‘yeast’ of agency and the heat of development. Not all of the ingredients are apparent in the finished product, but all are essential.
It would be easy to think that genetics is unimportant in the determination of behaviour. Over 90% of the prison population possesses a y chromosome, but being male is not considered a reasonable defence against criminal charges, and neither has anyone taken steps to prevent further violence by incarcerating all those in possession of such a chromosome (and perhaps that’s a good thing…)
Lahti spent the first part of his talk outlining some recent findings in the field of behavioural genetics, including alcoholism, trust, mate choice and political preferences. Amazingly (to me) there are indications of heritability for all of these traits, although because they are such broad categories it has proved difficult to find genes that play a major role in determining these characteristics. Continue reading →
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.