The situation in which allele frequencies in the gene pool remain the same over the course of time and the changing of generations is called a Hardy-Weinberg equilibrium. The conditions necessary for maintaining the equilibrium are that the evolutionary mechanisms (natural selection, genetic drift, and mutation) are not changing the allele frequency, that the population is indefinitely large and that mating occurs at random (that there is no preference for certain mates)
Allele frequencies remain constant in a population when they are in<span> </span>Hardy-Weinberg equilibrium. This is a law stating that<span> genetic variation in a population will remain constant during successive generations in the absence of disturbing factors. </span>
<span>The man has been contracted with pseudo membranous colitis which is the result of taking broad-spectrum antibiotics for an infection caused by a gunshot wound to the abdomen; this is because normal micro biota is wiped by the antibiotics resulting the overgrowth of Clostridium difficile in colon.</span>