The Hardy-Weinberg principle is not generally found in nature because it requires certain conditions in an environment. These conditions are the absence of the things that can cause evolution. In other words, if no mechanisms of evolution are acting on a population, evolution will not occur--the gene pool frequencies will remain unchanged.
Gum disease is a very common condition where the gums become swollen, sore or infected. The gums tend to bleed after you brush or floss your teeth, and the blood in your mouth causes the metallic taste. If left untreated, the tissues and bone that support the teeth can also become affected (known as periodontitis).
There are 26 conditions associated with metallic taste in mouth and sore throat. The links below will provide you with more detailed information on these medical conditions from the WebMD Symptom Checker and help provide a better understanding of causes and treatment of these related conditions.