A Dominant Allele Is Found in a Population with a Frequency

Essay

A dominant allele is found in a population with a frequency of 0.8.As the environment begins to change,the dominant allele is not favored.Scientists find that the frequency of the dominant allele decreases by half each generation.What are the allele,genotype,and phenotype frequencies before and one generation after the population begins to change? Is Hardy-Weinberg equilibrium maintained?