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Odor Selection


It makes sense that a human with excessive body odor may have trouble convincing other people to date them. Beyond that, most people probably do not think that smell is a major factor in deciding whom to date or with whom have children.

However, evidence suggests that there is a connection between personal odor and immune genes. Studies indicate that humans prefer the odor of individuals whose immune system genes are different than their own.

Which of the following could be the evolutionary benefit of people with different immune system alleles mating?


Over time, the number of individuals with the dominant phenotype for immune genes will increase, strengthening the population.


The number of individuals that are homozygous for immune genes will increase in the population, making it more likely that an advantageous trait will be passed on in future generations.


The resulting offspring will have a more diverse set of immune genes, protecting the population against a wider range of diseases.


The resulting offspring will smell better and will be sexually selected for, increasing the more pleasant smelling individuals in the population.