DNA seems to have a celebrity-like status within the public media sphere. It is used to catch the 'bad guys', resolve paternity disputes and tell you what medical conditions you are predisposed to. While it is true that DNA can do these things, the way that this 'magic molecule' is portrayed in films, TV programmes and other media formats isn't always accurate and can lead to confusion and misunderstanding amongst the public.
Professor Alan McHughen, a molecular geneticist and public science advocate, is keen to improve scientific literacy and to stop the proliferation of misinformation. Professor McHughen's new book 'DNA Demystified – Unravelling the double helix' has been specifically written to help readers sort the fact from the fiction concerning DNA and genetics.
The book starts with a general overview of the physical and chemical properties of DNA, complete with some handy diagrams and suggestions for additional resources that the reader can use to enhance their learning. Professor McHughen explains clearly how DNA stores our genetic information and how this information can be passed onto subsequent generations. This 'DNA 101' is followed by a brief history of the research that contributed to our understanding of how DNA works, spanning the theory of evolution proposed by Charles Darwin right up to the Human Genome Project and the dawn of genetic engineering.
I very much enjoyed Professor McHughen's anti-speciesism stance throughout these opening chapters. When posing the question 'What makes human DNA so special?', his candid response is 'nothing, actually'. He explains that 'DNA has the same structure and function – physically, chemically and biologically – in every living thing'.
He also shares that the human genome isn't particularly remarkable in the amount of DNA or the number of genes it contains. Professor McHughen believes that 'every species alive today can be considered equally successful, as we've all survived eons of evolutionary selective pressure that has wiped out countless 'inferior' species'.
Professor McHughen then focuses his attention of the practical applications of DNA, which was fun to read as it explored the reality behind the media headlines. Including, how DNA is being used in 'cold cases' to identify criminals, how DNA from pets and trees has been used as evidence to support criminal convictions and how DNA banking can be used to recover extinct, or near-extinct, species.
A significant proportion of the book focuses on direct-to-consumer (DTC) genetic testing. This form of genetic testing can be accessed by anyone and these tests do not need to be authorised by a medical professional. The results of DTC genetic tests are notoriously difficult to interpret and can create unanticipated confusion and anxiety for many participants. Professor McHughen's extensive and detailed examination of DTC testing manages to cut through this confusion and bring some much needed clarity.
Reading this book has cemented my decision not to participate in DTC genetic testing, however Professor McHughen's view is that some forms of genetic testing may be helpful, providing the consumer has a clear understanding of what can and can't be detected through the testing process. Nevertheless, the companies that claim to be able to identify a perfect wine for your palate or identify a potential romantic partner based on your genetics should probably be taken with a (huge) pinch of salt.
One of my favourite chapters within the book explores how genetic engineering is used within agriculture and food production. Professor McHughen astutely observes that when DNA technologies are used to create new forms of medicine, there is often little public outcry and these drugs are prescribed and taken without hesitancy, however, 'passions stir when the same technology is used to improve crops and food'.
Professor McHughen argues that genetic engineering is the 'most successful technology in the history of agriculture', however, food created from genetically modified organisms is still viewed with suspicion by the general public. Professor McHughen discusses how humans have technically been modifying the genes of crops for 'thousands of years'. In the earliest days of farming this was through the selective breeding of crops that displayed desirable traits. This was expanded further by exposing seeds and plants to mutagenic agents that can cause random changes in the genome in the hope of generating plants with new, advantageous properties, such as being able to resist specific pathogens or grow in regions with little rainfall. In contrast, the modern forms of genetic engineering are performed by modifying the plant genome in a very deliberate and precise manner which, you could argue, reduces the likelihood that a dangerous or unsafe crop could be created.
The book ends with two chapters that explore some of the ethical dilemmas that can arise through the use of DNA-related technologies and a consideration of how genetic technologies could help the human race survive in the future. The threats imposed by climate change, overpopulation and new diseases feel quite frightening and overwhelming, however, Professor McHughen remains optimistic that we can 'use our scientifically sound knowledge to inform policies to sustain our planet and our society'. He also believes that 'as bad as things seem, society is far better off now than it has ever been', which is a sentiment I find slightly harder to agree with.
Overall, this is an interesting and well-informed book that is written in a responsible and balanced way. It provides a good overview of the uses of DNA and tackles the misconceptions associated with DNA-based technologies. Professor McHughen has taken great care to make the book as accessible as possible and employs an impressive range of similes to describe complex genetic information in simple terms. Nevertheless, there is still a lot of technical information included within each chapter and as a result, the book is predominantly suited to readers with some prior knowledge of genetics.