Question

The Hardy-Weinberg equilibrium is a principle stating that the genetic variation in a population will remain constant from one generation to the next in the absence of disturbing factors. (a) State the assumptions of the Hardy-Weinberg equilibrium. [5] (b) The beak color of finches has a complete dominance relationship where black beaks are dominant over yellow beaks. There are 210 individuals with the genotype DD, 245 individuals with the genotype Dd and 45 individuals with the genotype dd. Given that p? + 2pq + q? = 1 and p +q=1, Find the expected frequency of the following: i dominant alleles, ii. recessive alleles, iii. individuals with dominant genotype, iv. individuals with heterozygous genotype and v. individuals with recessive genotype. (c) The next generation of finches has a population of 400. There are 336 with black beaks and 64 with yellow beaks. Is this population in Hardy-Weinberg Equilibrium?

Answer 1

(a) Assumptions of Hardy-Weinberg equilibrium include random mating, no mutation, no migration, large population size, and no natural selection.

(b) i. 420, ii. 90, iii. 210, iv. 245, v. 45

(c) No, the population is not in Hardy-Weinberg Equilibrium.

The Hardy-Weinberg equilibrium is based on several assumptions: random mating, no mutation, no migration, large population size, and no natural selection. These assumptions suggest that the genetic makeup of a population will remain constant over generations in the absence of external influences.

In the given scenario with finch beak color, the allele frequencies are represented by p and q. The expected frequencies can be calculated using the Hardy-Weinberg equation, where p² represents the homozygous dominant genotype (DD), 2pq represents the heterozygous genotype (Dd), and q² represents the homozygous recessive genotype (dd). The calculations yield the following expected frequencies: i. dominant alleles (p²), ii. recessive alleles (q²), iii. individuals with the dominant genotype (DD), iv. individuals with the heterozygous genotype (Dd), and v. individuals with the recessive genotype (dd).

In the subsequent generation of 400 finches, with 336 having black beaks (dominant phenotype) and 64 having yellow beaks (recessive phenotype), the observed frequencies deviate from the expected frequencies. This deviation indicates that the population is not in Hardy-Weinberg Equilibrium, suggesting the possible influence of factors such as natural selection or other disturbances affecting the genetic composition of the population.