Wednesday, January 13, 2010

Lab 05 - Heritability and quantitative traits

Today we did our lab in heritability, a calculation that can be done when dealing with quantitative traits.

Heritability: The proportion of phenotypic variation explained by genotypic variation (as opposed to environmental factors)

Broad sense heritability (H^2): Heritability taking into account all kinds of genetic interactions (additive effects of polygenes, epistasis, dominance-recessiveness, etc.)

We used finger print ridge count data to calculate the broad sense heritability of the trait. Every student took his/her own fingerprints and did a ridge count on each one. We pooled everybody's data and proceeded with the calculation.

Narrow sense heritability (h^2): Heritability taking into account only the additive effects of polygenes. This measure is of interest to individuals who are interested in selection programs with the goal of shaping a population according to their interests (e.g. farmers or cattle breeders).

We used height data from students, their parents, aunts and uncles, and siblings, to calculate h^2 in a human population (even though this is never done with any practical purposes).

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