Blackwell Publishing

Quantitative genetics - What statistical tools are used by quantitative geneticists?



Imagine the individuals have been measured for two characters, X and Y . The covariance between the two is defined as

cov(x,y) = (1/(n-1)) ∑ xiyi

Covariance measures whether, if an individual has a large value of X it also has a large value for Y . If the xi and yi of an individual are both large, the product xi yi will also be large; if yi is not large when xi is, the product will be smaller. Generally, if X and Y covary, the product (and so the covariance) is large; and if they do not, the sum of the products will come to zero.

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