The lion that killed an American tourist at a South African park is a tragic example of what lions evolved to do best—being a top predator, a scientist says.

According to reports, the African lioness attacked the female tourist through the open window of a car in Lion Park, a wildlife attraction 19 miles (30 kilometers) north of Johannesburg. The tour operator who was driving the car sustained injuries on his arm trying to fight off the animal.

"Almost any organism around lions might be a potential prey item, and for people to think that they are an exception is folly," says Luke Dollar, program director for National Geographic's Big Cats Initiative.

"I would imagine that every other primate that