Tuesday, 9 April 2013

The Epigenetics Revolution by Nessa Carey: Book review

Drink with this

Tequila sunrise

This may seem an odd choice of drink to partner a book about a relatively obscure branch of science. But as with genetic diversity, there are (almost) infinite variations on this seemingly straightforward classic. Southern Sunrise, Caribbean Sunrise, Tequila Sunset… Epigenetics is a new take on Darwin’s theories of evolution just as the tequila sunrise has contenders coming along to embellish on the original. This cocktail has distinct and discrete layers which slowly interact over time, a fitting metaphor for the interaction between genetics and the environment.

What’s what

For many years I have harboured a secret conviction that if not for doing an arts degree I would now be a successful and probably quite famous geneticist. My understanding of what this would involve on a day to day basis is limited, but I have always liked biology and I have a vague but blissful picture in my head of lots of research and no people at all. Just their cells, presumably.

A few months ago I suffered from a particularly desperate bout of career-induced panic, and resolved to jack in my media job to become a government advisor on the likelhood of a zombie plague. (This exists! I swear. (See last week’s review of Journal of the Plague Year for more on my morbid fascination with infectious illness.) 

I formulated a two-pronged plan, which conveniently glossed over such minor niggles as my lack of any sort of maths or chemistry qualifications obtained past the point when these subjects involved more than the odd quadratic equation and supervised play with a Bunsen burner. The first stage was to text my youngest sister, who has an actual real science degree and proper lab experience, to ask how one would go about becoming an epidemiologist. (What’s that?? She replied). The second prong of my devastatingly effectual life plan was to play to my existing talents, and read a few vaguely science-related texts. Which brings us to today’s review, after just two paragraphs of circumlocution and three sets of brackets!

Epigenetics is the study of gene expression. While an individual’s DNA remains constant from conception to death, certain genes function in different ways depending on their surrounding environment. Basically there are lots of add-ons on the genome, piggybacking genetic triggers which can cause the genes underneath to behave differently. This is important stuff - epigenetics has potential to change the way we treat inherited disease, obesity, cancer, and mental illness.

“Whenever two genetically identical individuals are non-identical in some way we can measure, this is called epigenetics. When a change in environment has biological consequences that last long after the event itself has vanished into distant memory, we are seeing an epigenetic effect in action.” Loc 151

Carey’s writing style was engaging and intelligent, most of the time. After reading the introduction I was a bit sneery, and felt that this book would be a bit juvenile for someone as expert as me. I had read the wikipedia page on epigenetics already you see. But it turned out Carey was just warming up! The book turned out to be pretty balanced on the whole. The start and end of every chapter were full of nice, easy to grasp explanations and examples, while the middles delved into the murky depths of chemical symbols and diagrams. I made sure to pick up on the terms being bandied about, so I can shout them out while watching University Challenge, so I know that ‘histone modification’ and ‘dna methylation’ are absolutely key. Beyond that I am a bit unsure - I have no shame in admitting I skimmed some of the denser pages. Hey, I did the same with all the War chapters of War and Peace and so far nobody has ever called me on it. *

There were plenty of examples given throughout of epigenetics at work, most of which related to genetically identical mice which had been studied in laboratories. I would have enjoyed more real world examples but it is inevitable that this were lacking as this is such a new area of research. Bonus points for the fact that one real world example involved Audrey Hepburn, and the genetic impact on her caused by the Dutch Hunger Winter.

Carey is a very careful writer and avoids rampant speculation. Nevertheless the book contained some genuinely fascinating and surprising revelations. For example, even genetically identical twins are epigenetically different, as their epigenetic profiles start to diverge while they are still foetuses, and then diverge further throughout their lives.

“Since epigenetic modifications don’t change what a gene codes for, what do they do? Basically, they can dramatically change how well a gene is expressed, or if it is expressed at all. Epigenetic modifications can also be passed on when a cell divides, so this provides a mechanism for how control of gene expression stays consistent from mother cell to daughter cell.” Loc 891

I found Carey’s effusive praise for the work of particular scientists quite odd - is this the done thing? I’m not sure I care about her speculations on who will win the next Nobel prize, and which scientist cuts a more dashing profile on campus. Her attempts to be funny were slightly more endearing but just as bizarre: ‘Shakespeare’s script’ for Romeo and Juliet being photocopied with Baz Luhrmann’s notes on it as an analogy for the epigenetic regulation of gene expression is a key example. But who knows, maybe Carey is a geneticist who has always dreamed of being a writer - in which case brava to her.

*Not sure who would but I live in fear of that mystery Literary Arbitrator anyway


A fascinating read. Accessible but also educational! What more could you want from non-fiction?

On the small screen

There is definite material for a Horizon special episode here! Who wants to help me pitch it to the BBC?


Any book with this many diagrams and anagrams has to be considered highbrow.

1 comment:

  1. Funny and educational review! Thanks.