Sample Hardy-Weinberg Problems Anthropology 1

1. For each of the following populations calculate the expected genotype frequencies. Recall that blood types M and N are homozygous and that MN is heterozygous. Assume Hardy-Weinberg Equilibrium.

Population Frequency of M Frequency of N

Pima Indians, Arizona .7 .3 Botswana San .6 .4 Indiana Amish .5 .5 Polynesians on Easter Isle .4 .6 2. In an isolated population of Berkeley undergraduates, the ability to smell Blondie’s pizza is determined by the dominant allele B, while the inability to smell it is determined by the recessive allele b. In a population of 100 such students, 60 are found to be homozygous dominant, 20 were heterozygous, and the remainder could not smell pizza. a. How many genotypes are there? b. How many phenotypes are there? c. What are the allele frequencies p and q? d. Is this population in Hardy-Weinberg Equilibrum? 3. A founder group of nomadic people split off from a parent population and establish a separate society. These emigrants have the following blood type frequencies: M=41, MN=38, and NN=21 for a total of 100 individuals. a. What are the allele frequencies? b. If the founder group meets the requirements of HWE, then what are the expected

frequencies of the three MN types in subsequent generations? 4. In cats, one form of manx (the congenital lack of a tail) is caused by the recessive allele t when present in the homozygous condition. For this reason, 27 of 300 cats do not have tails. Calculate the frequency of both alleles (p and q), as well as the three genotype frequencies. Assume HWE. 5. The ability to taste phenylthiocarbamide (PTC) is controlled by a dominant allele, T. The non-tasters are homozygous recessive, tt. Assume HWE. a. For the two populations, estimate the frequency of the t allele.

Russians in Moscow 412 235 647 Malays in Singapore 199 38 237

b. For each population, what fraction of tasters is expected to be homozygous?