The Wildlife of Our Bodies: Predators, Parasites, and Partners That Shape Who We are Today, by Rob Dunn (Amazon Kindle edition $US12.99)
If you feel squeamish when contemplating some of the weird stuff that mad old bag Mother Nature gets up to, this is not the book for you.
If, however, you like a good, well written book with some challenging ideas, you will enjoy this author and his ideas.
He is a good writer who likes metaphors - in his hands they don’t just mix; they go to parties, get drunk and dance the hoochie koochie together.
The pronghorn antelope still flees fast enough to outpace the North American cheetah which has been extinct for ten thousand years. Like the pronghorn antelope we are shaped by our past.
The body and mind which sits in an office all day is honed by natural selection for a nomadic existence of hunting and gathering.
Mankind has settled into a sedentary existence of farming and living in villages for a very short time and an even shorter one living in cities.
It is only yesterday that everybody lived outside, naked, infested with intestinal worms and covered with multitudes of microbes.
Humankind has gone from living within nature to lives in which nature has been largely eradicated in a very short space of time. Like the antelope our bodies remember the past whether we like it or not.
Dunn suggests much mental illness is caused by our response to long eradicated predators. The fear response and the urge to flee were triggered by hormones when we were defenceless on the savannah and fleeing from lions.
Distant and diffuse threats such as news of robbery, murder and mayhem, trigger the same responses every day. Fear and anger were lifesaving responses when our edible ancestors were hunter gatherers.
Today these responses lead to depression, phobias and other inappropriate mental responses to stress. These are medicated with drugs, both legal and illegal, with varying degrees of success.
Dunn concedes that the disappearance of cholera, malaria, dengue and big cats eating our nearest and dearest is an improvement, but recent research indicates there may be a price for living in an impoverished personal ecosystem.
That price may express itself in chronic illnesses such as diabetes, allergies, anxiety disorders and autoimmune disorders.
From Manhattan to Mumbai, when people join the middle class, start to wear shoes and use an indoor toilet they lose their intestinal worms. At the same time the incidence of autoimmune disease incidence of such as Crohn’s disease and asthma increases.
For the last fifty years medics and scientists have puzzled over this - and now are beginning to suggest a new solution- bring back the worms.
In early 1999 Dr Joel Weinstock dosed twenty nine individuals suffering from Crohn’s with whipworm (trichuris trichura) eggs. Twenty five patients stayed in the study and by week twelve of the study all but one patient was doing better and twenty one patients were in remission.
We have very little body hair because when we lived in caves (unlike other primates) we became unusually tick, louse and fly ridden.
People who grew less hair harboured fewer parasites, caught less parasite borne illness such as typhus and plague and produced more children.
This hypothesis is supported by modern women who feel that using hot wax to rip out pubic hair increases their sexual attractiveness . This practice has led to a decline in genital lice even as the incidence of gonorrhoea and chlamydia continue to rise.
There are some interesting ideas in this book which should be considered with an open mind.
We need wilderness and other animals to make us fully human, but I personally can do without itchy scratchy lice and fleas and man eating big cats roaming the suburbs.
Planting gardens on rooftops and walls of high rises and generally greening our cities sounds attractive –but once those roots and shoots started doing their work there would be even more leaky buildings than there are already.