The father of the science of evolutionary medicine, Randolph (Randy) Nesse, has a favorite aphorism: “Medicine without evolution is like engineering without physics.” In the same way that it would be impossible to imagine building the Rosetta spacecraft, sending it 300 million miles to rendezvous with Comet 67P, and successfully deploying the Philae lander, chock-full with sampling instruments, without physics and specifically Newtonian mechanics, it proves similarly impossible, for instance, to get to the root of the horrifying scourge of Alzheimer's disease unless we ask deep and fundamental questions, informed by evolution, about what the alleged poisonous plaques of beta-amyloid protein are doing in the brain in the first place. Is amyloid pure pathology or does it have an vital evolved function in the brain? In this sense, Nesse has frequently claimed that the value of evolution to medicine is that it while it may lead directly to changes in medical practice or indeed to new therapies, more fundamentally its value lies in explaining why things are as they are. That is why Nesse argues that evolutionary biology should be the foundation and cornerstone for medicine as it should be for all biology. This book is an attempt to put yet more flesh on the bones of Nesse’s idea that evolution is the “physics” of medicine. I describe the evolutionary background to seven areas of human disease that are causing deep contemporary medical concern to explain why they exist in the first place—why things are how they are - and how evolution might help us to combat them. I hope it will leave readers with a new respect for evolution as the prime mover for the structure and function of human bodies, even if it does, on occasions, cause them to break down and drives us into ER!

Each chapter is built around the sometimes harrowing but always inspiring personal stories of people trapped in the disease process in question. Each chapter provides an evolutionary explanation for why the disease has come about, and each chapter shows how medical researchers, using powerful insights gained from thinking about disease in an evolution-informed way, are charting our way out of it.

How a modern version of the hygiene hypothesis - called the "old friends" hypothesis - explains why the Western world is riddled with allergic and autoimmune diseases, and what we can do about it.
How evolutionary theory explains why the battle between the different selfish genetic interests of mothers, fathers, and fetuses causes low fertility and can lead to diseases of pregnancy like recurrent pregnancy loss, preeclampsia and gestational diabetes.
What is the relationship between the fact that we have evolved to walk upright - our bipedalism - and a range of orthopedic illnesses?
Creationists have always used the example of the "irreducible complexity" of the human eye as the bedrock of their argument that God designed the human body, not evolution. Modern developmental biology, however, not only strongly rebuts creationism but explains the astonishing secret of how the recipe for eyes actually unfolds from within the developing eye itself, not from external influences, and is leading to cures for eye diseases like retinitis pigmentosa and macular degeneration.
How does cancer evolve so remorselessly towards malignancy that it is proving almost impossible to cure? Cancer evolution can be so extreme and drastic it is forcing us to re-write the rules of evolution by resuscitating a heresy from the 1940s.
Why are coronary arteries evolution's answer to feeding our powerful, muscular hearts with the food and oxygen they need and how has this led to the continuing pandemic of coronary heart disease?
Research into curing Alzheimer's disease has become hopelessly bogged down and billions of dollars have been wasted trying to turn the "amyloid hypothesis" into therapy. Can we use evolutionary thought to better explain why dementia comes about in a way that might lead to fresh hope for a cure?


Wednesday, 23 November 2016

QRB review for Body by Darwin by Michael Ruse

Because the Quarterly review of Biology has a paywall I have published the review below the old fashioned way - I won't put in a link.

Body by Darwin: How Evolution Shapes Our 
Health and Transforms Medicine.
By Jeremy Taylor. Chicago (Illinois): University of Chicago Press.
 $30.00. vii + 252 p.; no index. ISBN: 
978-0-226-05988-4 (hc); 978-0-226-05991-4 (eb). 2015.

Thomas Henry Huxley started life as a medic. Trained at the Charing Cross Hospital, his first job was as an assistant surgeon on HMS Rattlesnake. On return to England, he left the consulting room and moved to the lecture hall and anatomy laboratory as he became one of Britain’s leading life scientists. But he never lost his connection with the medical profession. As he and his fellows labored to professionalize British science—making it an area where a talented newcomer could make a career—he realized that he could not teach (and be paid for it) unless he also found jobs for his students. Hence he sat on the London School Board, arguing for high school anatomy classes rather than the outdated study of ancient languages. Hence he snuggled up to the leading surgeons and physicians, arguing that he could give potential doctors a grounding in basic science that could then serve as the basis for training as a practicing medical doctor.

This led to a paradox, for although Huxley became the biggest spokesman for Charles Darwin’s theory of evolution through natural selection, he could see no place for the theory in his professional world. Natural selection may explain the patterns on butterfly wings—actually I am not sure that Huxley thought that it did—but it does not cure a pain in the belly. For this reason, in Huxley’s massive course of 165 lectures on embryology and anatomy—he had others teach physiology—less than 10 minutes was spent on natural selection. Evolutionary medicine was stillborn, to use an appropriate metaphor.

Things changed dramatically about 20 years ago, thanks particularly to the insights of physician Randolph Nesse and of biologist—and major force within this journal—George C. Williams. They argued persuasively that evolution does matter in understanding human health and sickness, and by evolution they meant evolution through natural selection. It would hardly be true to say that this is a tsunami that has swept the whole medical world, but the approach makes growing inroads. And it is to report on some of the successes and insights that science journalist Jeremy Taylor has written this book.

It is a great read. A real professional in his own field, Taylor has a good nose for a problem and a gift at explaining even the most complex science. He works by case study, looking at a range of issues. Why, for instance, a bit of dirt and worms might not be a bad thing for mental health. How having babies is not always just lovey-dovey, but can well involve quite nasty conflicts between the interests of mother and child. Why the success of your arboreal ancestors five or more million years ago might mean that your back aches every time you sit down. And a great one, why it is that breast cancer rates seem to be climbing and why going on the pill might stem the tide.This is not a textbook and as a philosopher there were times when I would have liked a bit more critical discussion of hypothesis testing and avoidance 
of “just-so” stories—where are you Sir Karl Popper when we need you? But the next time you are out on the golf links, when you get to the 19th hole you might push a copy on your general practitioner. 

Michael Ruse,

Program in the History & Philosophy of Science, Florida State University, Tallahassee, Florida.

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