And I kept asking myself this really simple question: if the ancestors to New World monkeys could somehow cross the Atlantic Ocean, why couldn't humans cross that tiny stretch of water?

果祖先新世界猴可以跨越大西洋，类不能跨越这小小的狭水域？

For example, the yellow fever virus is carried by African wild monkeys, whence it can always infect rural human populations of Africa, whence it was carried by the transatlantic slave trade to infect New World monkeys and people.

例，病病毒是由非洲野猴携带的，因此它总是可以感染非洲农村口，而跨大西洋奴隶贸易则携带病病毒感染新大陆的猴子和类。