BIOLOGY 1M03 Lecture Notes - Lecture 9: Sickle-Cell Disease, Heterozygote Advantage, Genotype Frequency
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A1a1 + a1a2 + a2a2 p^2 + 2pq/2 + q^2. Genotype frequencies: aa is 0. 54, aa is 0. 12 and aa is 1-0. 54-0. 12 = 0. 34. Allele frequencies: p= p^2 + 2pq + q^2 = 0. 54 + (0. 5)(0. 12) = 0. 60. Hypothesis: aving dissimilar hla genes from your mate results in a more variable and resilient immune system; hence, higher fitness. They find that the mhc (via la genes) influence both body odours and body odour preferences in humans and women"s preferences depend on their hormonal status (pill or no pill) Body odours appear to contain peptides specific to an individual"s mhc (hla genes). These can be detected in smell receptors in nose; recognized in brain. Why might this be adaptive to variation in offspring: avoid inbreeding. Prediction: expect to find genotype frequencies outside of equilibrium because evolution should be actively occurring. Explanations: mating is biased with respect to hla genotype, heterozygous individuals have higher fitness.
