HMB265H1 Lecture Notes - Lecture 13: Epistasis, Genotype, Heritability

• School: UTSG
• Department: Human Biology
• Course: HMB265H1
• Professor: Maria Papaconstantinou

Document Summary

There are very few traits that are controlled by one locus. Bell curve of variation often attained by complex traits. There are a few equations we can use to see how much phenotypic variation is attributable to genetic variation vs environmental variation. If all the phenotypic variation is attributable to genotypic variation, h2 = 1 (maximum) If all phenotypic variation is attributable to environmental effects, h2 = 0 (minimum) High values suggest that genotype is important in determining if trait arises due to segregation of particular alleles. However, h2 does not predict how progeny will perform on basis of parental phenotype. High values does not indicate that progeny will look like parents. Also it looks at background effects such as epistasis, etc --> not just on allelic effects. Studies on twins living in different areas allows one to observe effects of environment when the genetics are held constant. Can use to compute the genetic component for these populations.