Evolutionary medicine, also known as Darwinian medicine, is the use of evolutionary theory to better understand health and the diseases that afflict human beings. The field is an extension of modern medical science, as it takes into consideration the evolution of human biology in response to the changing environment. Evolutionary medicine also considers the mind; evolutionary psychology has attempted to explain human behavior. Some of the most applicable research, though, concerns the evolutionary basis of diseases that only started to appear after the creation of human civilization.
Charles Darwin never applied his theory of evolution to the study of medicine. Before Darwin's death, though, other scientists began to apply evolutionary ideas to the germ theory of disease, the theory that microorganisms were responsible for many diseases. This branch of evolutionary medicine developed over time as scientists discovered how certain bacteria and viruses adapted to the human immune system. This research was largely responsible for the development of lifesaving antibiotics. The irony, of course, is that the antibiotics gained from evolutionary medicine prompted the evolution of antibiotic-resistant bacteria such as MRSA.
Besides furthering the progress of pathological research, evolutionary medicine helps explain the reasons behind many of the body's structures and processes. For example, though the evolution of a larger birth canal would make giving birth an easier and possibly less dangerous process, a larger birth canal would decrease mobility and make females more susceptible to predators. Birth canal size, along with skin pigmentation and the existence of a blind spot, are all example of trade-offs and conflicts that exist despite the continued evolution of the human race.
Evolutionary medicine has also attempted to explain the reasons for human behavior. The basis of evolutionary psychology rests in the evolved biological processes of the human brain. From this foundation, evolutionary psychologists have attempted to explain human behavior. For example, courtship behavior is the many customs that evolved out of the evolutionary need to mate. Evolutionary psychology has many critics, though, who argue that human experience and development should not be reduced to simply the result of genes.
One of the most applicable fields of evolutionary medicine is applying its findings to afflictions that have only developed after the creation of human civilization. At the genetic level, the human body is designed for a hunter-gatherer existence. The most prominent example of mismatch between biology and civilization is the rapid increase of individuals with type 2 diabetes. The human race, sustained by meat and very few grains for most of its existence, is unable to quickly adapt to a diet filled with processed carbohydrates and sugar. At the same time, a more sedentary lifestyle has led to a host of chronic illnesses.
