How evolution works against us

First aired on Quirks & Quarks (21/12/2013)

Evolution has a lot to answer for, like: eye glasses, heart disease, bad backs, flat feet, impacted wisdom teeth and so on. One way to look at this is to say that humankind suffers from all of this because evolution has failed us. In The Story of the Human Body: Evolution, Health and Disease, Dr. Daniel Lieberman offers another view: he argues that we have outsmarted evolution and these ailments are the price we pay for being so smart.

According to Lieberman, evolution is more complicated than most people realize. So complicated in fact, that he contends that the world we have created is actually incompatible with humans. "We need to look at the whole story in order to understand it," he said. The complications have led to a series of trade-offs. TheStoryOfTheHumanBody-200.jpg

A major trade-off is that on one hand people are healthier than ever but they're also suffering from a variety of chronic diseases. Although we've learned to deal with infectious diseases, it's the chronic diseases like heart disease, osteoporosis and diabetes that are the problem. "The list is very long of diseases that are extremely prevalent today because of our lifestyle, that were unheard of or unimaginable as hunter gatherers," he said.

Lieberman called these diseases "mismatch diseases" that are "caused by our bodies being inadequately or poorly adapted to the environments in which we now live." He cites myopia as one example, because it is an eye disease caused by computer screens and not getting enough sunlight.

It's indisputable we have made great advances in science and medicine for dealing with ailments. But according to Lieberman, these technologies are aimed at fixing the symptoms rather than the causes. Heart disease is an example: instead of adopting a preventative strategy of tackling it through more exercise and better food, resources go toward curing it after the disease has struck. "I call that a vicious circle, a feedback loop -- a dis-evolution."

This book was one of the three best science books of 2013 selected by Quirks & Quarks. See the other selections here.

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