Through internet videos, tracing the African roots of twerk

I meant that larger buttocks was genetic, not the ability to do that particular dance
Of course there are black women with flat butts and white women with big butts, I am one of the white women with a big butt. This study Racial differences in body fat distribution among reproductive-aged women - PMC discovered that black women are more likely to carry weight in their legs and hips:

In conclusion, our study demonstrated that racial differences are present in the relationship between BMI and body fat distribution.

I researched this to avoid being accused of racism.

This African dance, while being very sensual, is not obscene. The Miley Cyrus version is made obscene by the addition of the man humping her butt.