Question

In a multilocus system (with no dominance at each locus) all of the following genotypes are favored by stabilizing natural selection. Which are examples of overdominance (i.e., heterozygote advantage) and which are not? There are 10 loci and each + or - is the allele at the locus

1. + + + + + + + + +
- - - - - - - - -
2. + + + + - - - -
+ + + + - - - -
3. + + + + - - - -
- - - - + + + +

Answer 1

In a multilocus system, some genotypes exhibit overdominance while others do not.

Step-by-step explanation:

In a multilocus system with no dominance at each locus, all of the genotypes are favored by stabilizing natural selection. However, some genotypes can exhibit overdominance, also known as heterozygote advantage, while others do not. For example, in the genotypes + + + + - - - - + + + + - - - -, the heterozygous genotype + + + + - - - - is an example of overdominance because it has a higher fitness compared to the homozygous genotypes. On the other hand, the homozygous genotypes + + + + + + + + + and - - - - - - - - - do not show overdominance.