Lewontin's Fallacy

"A proper analysis of human data reveals a substantial amount of information about genetic differences. What use, if any, one makes of it is quite another matter. But it is a dangerous mistake to premise the moral equality of human beings on biological similarity because dissimilarity, once revealed, then becomes an argument for moral inequality. One is reminded of Fisher’s remark in Statistical Methods and Scientific Inference 'that the best causes tend to attract to their support the worst arguments, which seems to be equally true in the intellectual and in the moral sense.'" -- A.W.F. Edwards, "Human genetic diversity: Lewontin’s fallacy" (.pdf).