Unfortunately, the origins of human language prove harder to trace than any other origins of the human species. The underlying problem with human language is that there are not many historical traces. Until recently it may have been viewed as hopeless to do more than speculate when language commenced. There are two exploding bodies of knowledge that may build bridges across the seemingly unbridgeable gulf between animal and human sounds starting from each of its opposite shores. Sophisticated new studies of wild-animal vocalizations, especially those of our primitive relatives, constitute the bridgehead of the animal shore of the gulf.
Animal sounds are ancestral to human speech.
Since human language has advanced so far over animal sounds it is unclear to locate the bridgehead on the human shore. Scientists have been studying animal sounds for centuries. As part of the monkey species, vervets are predominant in east Africa. Like other animals, vervets regularly face situations in which efficient communication and representation would help them to survive. Vervets have complex social relationships with each other.