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.
Some pregnant women experience a metallic taste in their mouth during the early stages of pregnancy, because of the hormone changes. It's also fairly common to crave certain foods, or go off certain foods, and have a heightened sense of smell.
Metallic Taste and Taste Disorders. Key points. A metallic taste in your mouth is a type of taste disorder known medically as parageusia. Common causes include new medications, pregnancy, and food allergies. In rare cases, metallic taste can be a sign of Parkinsonâs or Alzheimerâs disease.