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).
What is a metallic taste? A metallic taste is a distorted sense of taste in your mouth. A metallic, bitter or foul taste in the mouth is also referred to as dysgeusia. A lack of or change in taste can be due to anything that interferes with the normal taste process. Taste and the flavors you perceive are the result of a combination of the sense of smell and sensory neurons in your taste buds, which tell the brain what substances you taste (sweet, salty, sour and bitter).