Question

The color distribution for a specific population of lizards is 170 red, 50 orange, and 30 yellow. The allele for the color red is represented by R^R, whereas the allele for the color yellow is represented by R^y. Both alleles demonstrate incomplete dominance. Use the information to answer the following questions. Calculate to at least two decimal places. What are the genotype frequencies in the population? R^RR^R R^RR^Y R^YR^Y What is the allele frequency of R^R in this population?

Answer 1

Genotype	Number of individuals	Genotypic frequencies
RRRR	170	170 / 250 = .68
RRRY	50	50 /250 = .20
RYRY	30	30 / 250 = .12
Total	250

Thus, this entire population consists of 500 (250 X 2) alleles at the colour locus.
To deter mine the allelic frequencies we simply count the number of R^R or R^Y alleles and divide by the total number of alleles. So the allelic frequency for the R^R allele will be:
f(M) = [(2 x 170) + 50]/500 = 0.78

GENOTYPE FREQUENCIES
R^RR^R = 68
R^RR^Y = 20
R^YR^Y = 12

ALLELE FREQUENCY
R^R = 0.78