Razib inspired me to share some of the story behind why white people are considered derivatives.
No red herrings, here! Lamason et. al. found a single gene that controls human skin color while studying pigmentation in zebra fish (1). These zebra fish had an unusual golden color that turned out to be an important clue. Lamason and collaborators found that the golden zebra fish lost their normal color because of a mutation in the slc24a5 gene. When the zebra fish have the mutant form, they produce fewer melanosomes.
