Sandra Blakeslee in the New York Times:
The theory argues that juvenile diabetes may have developed in ancestral people who lived in Northern Europe about 12,000 years ago when temperatures fell by 10 degrees Fahrenheit in just a few decades and an ice age arrived virtually overnight.
Archaeological evidence suggests countless people froze to death, while others fled south. But Dr. Sharon Moalem, an expert in evolutionary medicine at the Mount Sinai School of Medicine in New York, believes that some people may have adapted to the extreme cold. High levels of blood glucose prevent cells and tissues from forming ice crystals, Dr. Moalem said. In other words, Type 1 diabetes would have prevented many of our ancestors from freezing to death.
The theory is described in the March 30 online edition of Medical Hypotheses, a journal devoted to publishing bold, even radical, biomedical theories that are potentially important to the development of medicine.
More here. [Thanks to Timothy Don.]