Disambiguous (disambiguous)

Our prematurity brought a second big advantage: it forced us to communicate. A newborn human is so helpless that it cannot survive without communicating its needs. Many babies died in the past. But some babies were better at signaling their needs, and some mothers were better at interpreting the signals. Babies who got their needs met lived to pass on their genes and their mother's genes. We were thus naturally selected for the ability to communicate.