While any individual action in a zero-tolerance culture will be evidence of endemic racism, the plain fact is actual racism is below any level in history and dropping fast.   That makes it possible to again discuss variations in skin color to provide one of the best examples of evolution by natural selection acting on the human body.

Scientists have understood for years that evolutionary selection of skin pigmentation was caused by the sun. As human ancestors gradually lost their pelts to allow evaporative cooling through sweating, their naked skin was directly exposed to sunlight. In the tropics, natural selection created darkly pigmented individuals to protect against the sun.
This is a butterfish:



NOAA describes it unflatteringly as a "small, bony foodfish." Butterfish live along the Atlantic coast of North America from Florida to Newfoundland, and they've been fished commercially for some time, with predictable results: