Rafael Núñez, a cognitive scientist at the University of California, San Diego, and one of the leaders of QUANTA, accepts that many animals might have an innate appreciation of quantity. However, he argues that the human perception of numbers is typically much more sophisticated, and can’t have arisen through a process such as natural selection. Instead, many aspects of numbers, such as the spoken words and written signs that are used to represent them, must be produced by cultural evolution — a process in which individuals learn through imitation or formal teaching to adopt a new skill (such as how to use a tool).