Book Reviews

Book Reviews

Survival of the Sickest

By Stephen Northcutt
Version 1.0

Survival of the Sickest by Dr. Sharon Moalem

This book is about natural selection or evolution and is a fascinating read. The basic premise is that sometimes our bodies adapt to various threats, but the adaptation may one day kill us. One example is the amount of iron in the blood. Too much iron and you rust to death, (hemochromatosis). Too little and you are anemic, that is me at the present time, though when I was younger I had too much and gave blood at the Red Cross once a month to keep it under control. But what does any of this have to do with natural selection? The book talks about one of the worst epidemics in the known history of mankind, the bubonic plague. In Europe somewhere between one third and one half of the population died a gruesome death.

A disproportionate number of casualties in most epidemics tend to be the very young and very old, no surprise there, we see that today with the flu. However, the bubonic plague killed more men aged 15 - 44 than women by a factor of two to one. One difference between men and women is menstruation, where blood, therefore, iron is lost. The young and old tend to have poorer diets, especially in 1347 and the following years, while the working men tended to get the better share of food having more iron in their bloodstreams.

What does this have to do with natural selection? Long before the plague a condition developed in the Norse population called hemochromatosis, where the body absorbs too much iron from the food we eat. Perhaps this was in response to the harsh conditions of Northern Europe and limited diet. But this mutation made the population that carried it less likely to die of the plague, though if they survived the plague and left the harsh environment of the North, they die is older age.

One more example from the book is blood sugar or glucose. Too much and you develop diabetes. I just had my physical and am deeply thankful that I am not diabetic or pre-diabetic, but about 1 in 10 Americans have the disease. It is now the 7th leading cause of death. The more I read about Diabetes Mellitus, the more I do not want to develop it, so my family has switched to a diabetic diet. Of course you have to have glucose to survive and so we depend on the pancreas to produce insulin to manage glucose. Once again, the human population exposed to extreme cold such as Inuit hunters have adaptations such as the Lewis wave to resist frostbite. They also have something most of us don't have called brown fat, when it encounters glucose it creates heat immediately, no insulin required. What happens to folks that come from generations of exposure to extreme cold if they move to Miami? They are at a higher risk than 1 in 10 of developing diabetes.

I do not want to steal any more of the author's thunder, but I hope you get the idea. The book is a great read, the author has a sense of humor. The biggest takeaway for me was the Jump in the Gene Pool chapter. As I start to think about retirement, I am trying to make intelligent investments to fund retirement. I am going to take a close look at companies in the genetic pharmacology space such as Seattle Genetics, ( though the side effects of ADCETRIS make me think this should be a fairly meager investment).