there are racial and ethnic differences in IQ

[bunny]

I'm interested in how the people who claim there is no biological justification for race came to that conclusion. It seems to me "obvious" that Nancy Reagan is a good example of a white woman and Mohammed Ali is a good example of a black man. It doesnt matter to me that there are some people hard to classify by race (or even by gender) - it is still a meaningful and objective classification.

In a similar way - in Australia April is a warmer month than July - there are exceptionally warm july days and cold april days, it doesnt mean that the distinction is meaningless, though.

I have seen race defined as (something like) "A biologically distinct subdivision of a species possessing certain gene frequencies" in evolutionary biology textbooks. Under this definition it is incorrect to consider a race as a bunch of creatures all approximating some sort of "platonic ideal". It is also incorrect to state that all members of a particular racial group have certain characteristics. The definition is more probabilistic.

Would this sort of definition be useful in generating an objective measure?