ANTH 1001 Study Guide - Quiz Guide: Heterozygote Advantage, Mutation Rate, Point Mutation
Document Summary
However, mutation rate for any particular allele is low. Due to heterozygotes having higher tness than homozygotes. Malaria: caused by a parasite transmitter between individuals by mosquito. Heterozygotes for sickle cell have selective destruction of rbcs: uninfected rbcs do not sickle; infected rbcs sickle and kill parasites. Heterozygotes can conjointly supply oxygen to tissues and suppress parasitic proliferation. In malarial environment, heterozygotes for sickle cell have natural selective advantage over homozygotes for normal hemoglobin and sickle cell. Because of heterozygote advantage, alleles for both normal and sickle cell hemoglobin are maintained at high frequencies; this is a balanced polymorphism. Evolution of balanced polymorphism for sickle cell: spread of slash-and-burn agriculture is related to natural selective advantage of sickle cell allele. Selection cuts on the phenotypic/genotypic variability that exists in a population. Pops. differ in their rbc mutations: sickle cell, thalassemia, and g-6-pd. Rbc variants is selectively advantageous in malarial environment; consequently, each rbc variant is sustained by natural selection.
