Asmall group of people left their homeland and set sail for a tropical island. They settled there, and their descendants lived for many generations. Unfortunately,a relatively high proportion of this new population is afflicted with an autosomal-recessive disease. What would explain this?

Question

Quizplus · Accepted Answer

Even if only one member of the original group was heterozygous for a specific disease-causing gene allele, children from this limited population were likely to intermarry, increasing the incidence of that particular haplotype. By the fourth generation and beyond, so many of the population would be carriers of this disease-causing allele that its expression increased. Some modern examples of this process include groups who have socially isolated themselves and intermarried to such an extent that recessive disorders appear dominant because of the increased incidence, such as the old-order Amish, Ashkenazi Jews, and French Canadians from the Quebec area.

Asmall Group of People Left Their Homeland and Set Sail