This is one of the most challenging, and fascinating, books I have ever read.

Although it is a decade old now, its account of the science of genetics is still relevant. The author, a respected genetics and biochemical researcher, takes the reader from the basics of DNA and genes to important questions about disease and genetic engineering.

And he raises (and answers) some deep ethical questions from a christian viewpoint.

Denis Alexander

Author Denis Alexander has an impressive resumé, beginning with study at Oxford, a PhD in biochemistry. Since then he has worked for almost half a century in biological research.

He has helped establish several university biochemistry and genetics departments and laboratories. More recently, he has worked in molecular immunology and cancer research in the UK.

Alexander is an evangelical christian who believes that science and christian faith are quite compatible. As a biologist he is quite comfortable with evolution. In 2006, he helped set up the Faraday Institute  for Science and Religion at Cambridge University, and was for a time its director. The Institute is “interdisciplinary research institute improving public understanding of science and religion.”

He has written a dozen books and numerous scientific papers. We can know that he is well qualified to write this book.

The complexity of genetics

I have never studied biology, so I found the initial chapters quite challenging. First is an overview of the history of genetics and patterns of inheritance. Then the book plunges you into a world of biochemical molecules and processes – nucleotides, mRNA (messenger RNA), codons, tRNA (transfer RNA), amino acids, genes and so much more. This allows Alexander to explain how the information in genes is used to build new cells.

I had to read these early chapters several times to get it into my head as much as I could. But these chapters are necessary as they support the discussion of topics such as:

• How animal and human bodies are built from initial conception through the growth of many different types of cells (more than 200 in humans).
• How the twenty-one thousand protein encoding genes in the human body can be switched off or on in different cells.
• How genes can vary and mutate.

With this basic understanding, Alexander goes on to explore some interesting topics such as:

• The genetics of human evolution, and how genes are crucial in explaining how natural selection works.
• The complex tree of life, and how genetics shows common ancestry.
• The variations in the human genome (our complete genetic material – 23 pairs of chromosomes) and the diversity in the human race.
• The genetic basis of disease.
• Epigenetics – inheritable changes in chromosomes that change characteristics without changing the DNA sequence. This was one of the most fascinating chapters, and explained a lot about disease and the body’s processes of combatting them.

Difficult questions

In the last few chapters, Alexander discusses the deepest questions of human life, ethics and medical science:

• Genetic engineering – it happens naturally as well as via human intervention, but how far can and should we go?
• Genetically modified foods – not as scary as some think (he says).
• Stem cell research – why stem cells are so important, and why we may be able to use different processes to achieve the same result.
• Human identity – are we really no more than gene machines?
• God and evolution – is evolution wasteful, and why would a good God use such a process based on suffering and competition?
• Determinism and human responsibility.

I found his responses to these questions quite sophisticated and interesting.

He shows that christian opposition to the idea of evolution is really only recent. God has used evolution to create humans (and all life). He says genetics provides one narrative about the world, while theology provides another. The christian narrative explains how science is possible – because the universe conforms to reliable laws.

He believes that DNA manipulation has great scope for reducing disease and suffering. But he doesn’t believe determining the characteristics (e.g. height, IQ or hair colour) of a child is likely any time soon (if at all). Most of these characteristics are determined by hundreds of genes, so engineering them would be impossibly difficult.

I thought his discussion of determinism and responsibility didn’t answer the difficult questions. He says we are not determined by our genetics because there is so much scope for variability in genetic inheritance and epigenetics. But he didn’t explain how a physical brain could escape the determinism of cause and effect processes. (I find that no less a person than philosopher Michael Ruse agrees. Apparently Alexander is a “Developmental Dual-Aspect Monistic Emergentist” on determinism. My understanding is limited, but I don’t feel that is an explanation of a difficult question.)

I heartily recommend this book

If, like me, you think genetics is a crucially important aspect of life, and you want to understand it better, I encourage you to check out this comprehensive and authoritative book.

The Language of Genetics. Denis Alexander. Templeton Press, 2011.