https://theconversation.com/how-a-handful-of-prehistoric-geniuses-launched-humanitys-technological-revolution-171511 https://twitter.com/Kyukimasa/status/1476551349118849027 弓を発明したのは一個人(一部族)である可能性 https://images.theconversation.com/files/438915/original/file-20211223-19-1rzho5.jpg