Biology concepts and applications

Biology

Medicines have been in use for centuries, from simple herbs back during the Neolithic era, to the advanced artificial drugs of today. Mankind has always strived to be rid of disease, and the advance in medicine has shown that. A question that can be asked with this advance is; does treating common colds, runny noses, or diarrhea provide a survival benefit for society? At first glance the answer to this question is yes, however, when put into a Darwinian perspective the answers become a bit less clear.

Natural selection is the theory that beneficial traits are more likely to reproduce than unbeneficial traits. A brown squirrel that blends in with his environment is more likely to survive than a neon green squirrel, and thereby the brown squirrel might survive long enough to mate and pass along its desirable trait.

How then are illnesses like common colds beneficial to the survival of mankind? The answer is that they are not.

Professor Nesse states, "We get infections because pathogens evolve faster than we do."(Nesse 1995)

Common colds are not natural traits that affect our survival, they are separate beings that enter our body and wreak havoc. The way they affect our bodies were created and adapted by natural selection. Runny noses, diarrhea, and fevers evolved over time as a way to fight back against pathogens that could potentially harm our body.

Vomiting provides a quick way to get rid of something dangerous inside the stomach. The same goes for diarrhea.

Coughing purges the lungs of harmful bacteria, which is why doctors tell the patients to cough after a surgery. But these defenses are employed so often within the body that they sometimes appear to be overused. Some people are overly prone to vomiting, some to bouts of runny noses.

The answer to why these reactions are so ubiquitous lies in efficiency. Expending a few hundred calories to vomit is much more efficient than being crippled by a disease that will threaten a life for weeks. If there is even a small chance, approximately five percent to be precise, that the chemical in the stomach is toxic, then the body will initiate vomiting. Only when the toxin is below the five percent mark will the amount of calories expended be inefficient enough to cause the body not to vomit.