People seem to be able to understand gestures made by chimpanzees, suggesting the signals may be remnants of a basic sign language used by our last common ancestors
Source:
https://www.newscientist.com/article/2216353-we-may-have-a-basic-form-of-sign-language-in-common-with-chimpanzees/?utm_campaign=RSS%7CNSNS&utm_source=NSNS&utm_medium=RSS&utm_content=home