منابع: 1¬)¬ How Did Language Begin? Ray Jackendoff: https://www.linguisticsociety.org/content/how-did-language-begin . 2¬: Why Can't Chimps Speak? Key Differences In How Human And Chimp Versions Of FOXP2 Gene Work https://www.sciencedaily.com/releases/2009/11/091111130942.htm . 3¬: The study of language : George Yule 4: The origin of language: Evolution's greatest mystery https://youtu.be/RnGiaz5PLbM https://youtu.be/S7cQ3b0iqLo