The prevalence of lactose intolerance is extremely interesting…not extremely…but notable, anyhow.  Lactose intolerance is way more common in people of African descent that in people of European descent.  As babies, we all have the enzyme lactase that breaks down the lactose in breast milk.  But once we reach the age when our moms’ boobs don’t look so appetizing, our bodies gradually stop producing lactase.  Northern European culture incorporates more dairy farming, thus the ability for the population to sustain lactase production is greater.  So, remember—if you happen to stumble upon some back-alley, gambling contest between a white guy and a black guy of who can drink the most breast milk before getting sick—bet on the white guy.  Actually just run away.  That’s not a game you want to be part of.