6 December 2002 20:00 GMT

by Henry Nicholls

There is a fundamental flaw in the way that medical students are being taught, says a group of leading scientists, who believe that a more thorough understanding of evolutionary biology would reveal new ways to prevent and treat disease.

In failing to teach young medics about evolutionary biology, "there's been a terrible accident in medical education," said Randolph Nesse, professor of psychiatry at the University of Michigan. "Practicing medicine without evolutionary biology is like trying to do engineering without calculus," he said.

A couple of hundred scientists from nearly as many disciplines gathered in London today to show support for 'Darwinian medicine', which offers a framework for understanding how some of the biggest problems facing modern medicine, such as malaria, cancer and HIV, might be informed by an understanding of Darwinian natural selection.

Almost everything about the human body, including the diseases it is subject to and many of the symptoms it expresses, are the product of natural selection, urged Nesse and professor Mel Greaves of the UK's Institute of Cancer Research, joint organizers of the meeting Evolution and Disease.

Bringing an evolutionary slant to his subject, Greaves suggests that cancer is an inevitable consequence of an evolutionary trade-off. Our stem cells, for example, are essential for embryonic development and replenishment of tissues throughout life. Ironically however, their longevity and proliferative potential - the very design features that make them indispensable to us - "renders them the major targets for cancerous transformation."

With this is mind, said Greaves, "We need a new way of thinking about cancer treatment." Whilst current therapies are often successful at removing cancerous cells, they are not tackling the problem early enough, he says. Cancer treatment would improve if clinicians attacked "the landscape on which cancer cells depend", rather than just the cells themselves, he suggested.

Nesse criticized the education system for giving doctors a narrow view of disease. "What the general physician does mostly is block fever, nausea, vomiting and diarrhea," he said. But these are all "normal responses," he warned, and removing them often prolongs a patient's illness.

In addition to shifting our perspective on disease, evolutionary thinking also explains many quirks of the human body. To illustrate some of the apparent imperfections that bear the hallmark of evolution by natural selection, Nesse offered a rapid redesign of human anatomy and physiology. He dismissed the appendix as a "no-brainer", then whipped out the wisdom teeth, reversed the eyeball, strengthened bones, improved the immune system, and had an ingenious suggestion for easing the trauma of childbirth. "Install a zipper so babies can get out more easily," he said.

A Darwinian view of medicine "integrates a lot of knowledge, predicts how the body works and why it fails, and it gives just a more accurate view of disease," Nesse told BioMedNet News. "This is a field whose time has come," he said.

"I think it's important to teach Darwinism to everybody," said Richard Dawkins, professor of zoology at the University of Oxford and author of numerous books on the subject. "And if it's important to each it to everybody, it's ten times as important to teach it to doctors," he told BioMedNet News.

However, in spite of Nesse's optimism and Dawkins' keenness to get Darwinian thinking through to the medical profession, only about 30% of US doctors surveyed by Nesse thought there was a role for teaching evolutionary biology at medical school. "It's going to take a long time to get the message across," admitted Greaves.

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