人類はいつから言語を使い始めた
It was mostly undisputed that pre-human australopithecines did not have communication systems significantly different from those found in great apes in general. However, a 2017 study on Ardipithecus ramidus challenges this belief. Scholarly opinions vary as to the developments since the appearance of the genus "Homo" some 2.5 million years ago. Some scholars assume the development of primitive language-like systems (proto-language) as early as "Homo habilis" (2.3 million years ago) while others place the development of primitive symbolic communication only with "Homo erectus" (1.8 million years ago) or "Homo heidelbergensis" (0.6 million years ago), and the development of language proper with Anatomically Modern "Homo sapiens" with the Upper Paleolithic revolution less than 100,000 years ago.
100,000 years