I don't want to read too far into your comment, but if the intent was similar to: "Interracial children don't fall into classical racial categories and, as such, are proof that racial categories don't exist," that's fallacious. The fact that a lab and poodle can produce a labradoodle doesn't negate the fact that labrador and poodle are dog breeds. The spaniards had a system that classified people by percentages of ancestry, e.g. quadroon, octaroon. Today we have more modern technology and ancestry can be determined though the analysis of genetic markers. The usefulness of race can be (and is) debated. Its existence is hardly debatable.
Is there anybody that does not have mixed ancestry? Where are the human labs and poodles?
The only real argument is that discrete categories do not exist. What this means is that for the vast majority of cases, the expression of phenotype A is not strictly linked to the expression of phenotype B. That said, it's quite obvious that there is a geographical and cultural distribution of genes.
Humans are not dogs, our populations are not strictly controlled for the purposes of winning dog shows. Attempts to do so are racist, in that they are (scientifically misguided) attempts to create or purify a race. Such as when your parents don't want you to marry someone who doesn't look the same.
> The only real argument is that discrete categories do not exist.
And yet they're 'discrete' enough that certain drugs are more effective on specific 'races' (or groups of people who share certain genetic traits if you prefer) than others.
I'm all for equality. I'm all for being judged and identified by your individual traits irrespective of the groups you're a product of. But this race/gender doesn't matter (or even exist) stuff has gotten to the point that it's as bad as the old christian movements when it comes to blocking scientific progress.
> Humans are not dogs, our populations are not strictly controlled for the purposes of winning dog shows. Attempts to do so are racist, in that they are (scientifically misguided) attempts to create or purify a race. Such as when your parents don't want you to marry someone who doesn't look the same.
I consider politics quite the dog show, and people have been self-selecting their mates on the basis of looks, culture, and politics for as long as they've been on this Earth. Seeing if this has resulted in genetic differences is a question of science, but deciding whether this activity is ethical is a question of value.
That's really the heart of the matter. As long as people believe scientific conclusions reflect personal values, we'll never be able to address any of these issues effectively.