Gorillas can not only learn sign language, they can teach it as well.
It’s called “cultural transmission” when culturally relevant knowledge is passed from one person to another, or from parent to offspring, or from culture to culture.
Will Koko transmit the sign language she learned from our culture to her baby (if we’re fortunate enough to help her have one) — without any intervention from us? All of the experience we’ve had so far with Koko suggests she will. For example, in this video, Koko molds the hands of her orangutan doll into the sign for “drink.”
We’d like Koko to fulfill her wish to have a baby for a number of reasons. This is just one of them — to establish cultural transmission in a way that “extends her ambassadorship” to at least one other great ape who can “speak” out on behalf of saving his/her own species!