> Or that asians and whites have wildly different reactions to milk.
Asians and whites don't have wildly different reactions to milk. Adult mammals are generally lactose intolerant. There is a mutation that, in humans, is found far more often in people with ancestry in Northern Europe (which isn't coextensive with "whites") than any other origin, but which is neither universally absent in all other people or universally present in people of that origin that results in lactose tolerance.
Most supposed "racial" differences (EDIT: that is, most that refer to anything that is actually a measurable difference between real human populations at all) are of this type -- things that are statistically more or less common in a population of a particular origin that is not coextensive with any of the usual "race" categories with which the supposed hard-and-fast difference is popularly associated.
Asians and whites don't have wildly different reactions to milk. Adult mammals are generally lactose intolerant. There is a mutation that, in humans, is found far more often in people with ancestry in Northern Europe (which isn't coextensive with "whites") than any other origin, but which is neither universally absent in all other people or universally present in people of that origin that results in lactose tolerance.
Most supposed "racial" differences (EDIT: that is, most that refer to anything that is actually a measurable difference between real human populations at all) are of this type -- things that are statistically more or less common in a population of a particular origin that is not coextensive with any of the usual "race" categories with which the supposed hard-and-fast difference is popularly associated.