Question

You are a population geneticist and you have recently visited a remote pacific island where you have discovered a race of giant purple-skinned, seven-toed, three-horned dragons. in examining the new race you have discovered that a small number of the dragons have only six toes as opposed to seven and it seems to be genetically inherited trait. after a population survey, you have found that in a population of 1,378 dragons, 174 of them have only six toes. assuming the six-toed organisms are carrying a recessive trait, calculate the gene frequencies and the percentage of homozygous dominant, heterozygous, and recessive individuals on the island

Answer 1

Use the Hardy Weinburg equation of allelic frequency.

P2+2pq+q2=1

174/1378 = 0.126 = q2

Therefore q2 = 0.126; q = 0.355

If q = 0.355 and we understand that p + q = 1, then

P = 1 – 0.355 = 0.645

To find homozygous dominant population (p2);

(0.645)2 x 1378 = 0.416 x 1378 = 573

Heterozygous popualiton (2pq);

(2 x 0.645 x 0.355) x 1378 = 0.458 x 1378=  631

Recessive indviduals (q2) =  174