This book is a little more wide-ranging that I first expected. I had thought the book would be purely about the microscopic life inside of us – species of bacteria and such things – with which we form symbiotic relationships, and how it has shaped us as human beings. Whilst much of the book focuses on this, we also look at the general ways in which how we live and respond to stimuli in the modern world still reflects strongly our historic interactions with all of life, especially predators. All kinds of areas of life – from the way we construct buildings and streets – seem to have been influenced to an impressive extent by the interactions we had with other life when in a more pure state of nature.
What it comes down to with this book – and it’s probably one of the best things you can say about a book – is that I learned a lot and had great fun doing so. There are many interesting little nuggets of information that I wasn’t aware of – I had no idea, for instance, that even today most human births take place during the night, with the likely explanation being that this is the time when, in the past, other members of the community would have been around to provide protection if necessary from predators during those first few moments of the child’s life.
Then there are the big, new ideas that perhaps most of us won’t yet have heard of. One of these is the interesting possibility that many diseases we suffer from in modern times are the result of our losing our intestinal worms and internal bacteria. The argument is that our bodies evolved in such a way as to accommodate this life inside of us, and even to benefit from it – so now we’ve removed some of this life, through the overuse of antibiotics and so on, our bodies can’t function as they were supposed to. This is one reason why, the book argues, that we need in some sense to return to nature, and to restore relationships with other organisms that we have lost.
There are fascinating human stories to compliment the science – which, I should say, is always well presented. We meet Crohn’s disease patients, for instance, who, desperate to get better, travel far from home to seek out worms in order to ‘re-wild’ their bodies, often with a lot of success. And when Dunn is retelling the stories of how some of the new ideas in the book were investigated, there’s suspense in the writing as we eagerly wait to discover the results of experiments, and whether evidence for these new ideas comes up.
Add to this that there is humour and a sense of fun in Dunn’s writing – and this is a book well worth reading. If you want to understand how living things inside of us and around us have shaped and continue to shape human beings, I would recommend this.