Human height heritability study A survey of UNCG Genetics students examined the heritability of human height. It can be shown that, under certain conditions, the slope (b) of the regression of a person's height on the height of their same-sex parent can be used as an estimate of half of the narrow-sense heritability (i.e. b = (1/2)h2).The data are plotted above. Results of the analysis were as follows: males only (number of samples = 12): b = 0.40 (p-value = 0.06) females only (number of samples = 17): b = 0.40 (p-value = 0.26) combined, with adjustment for sex (number of samples = 29): b = 0.40 (p-value = 0.04)

Using the combined data from males and females, the estimate of narrow-sense heritability would be:

h2 = 0.08
h2 = 0.80
h2 = 0.40
h2 = 0.04
h2 = 0.20

Part B
The statistical test of the regression slope evaluates how likely it is that we would have obtained a slope this large if the true heritability were zero.  The usual p-value threshold for a statistical test is 0.05.  Thus, what is the correct interpretation of the p-value of 0.04 in the combined analysis?

The p-value is less than 0.05, supporting the hypothesis that height variation lacks a genetic component.
The p-value is less than 0.05, supporting the hypothesis that height variation has a genetic component.
The p-value is less than 0.05, so there is insufficient evidence that human height variation has a genetic component.
The p-value is less than 0.05, rejecting the hypothesis that height variation has a genetic component.
asked Nov 18, 2013 in Genetics