Oldest stone tools pre-date earliest humans "Oldest stone tools pre-date earliest humans" Oldest stone tools pre-date earliest humans "Oldest stone tools pre-date earliest humans" BBC report Oldest stone tools pre-date earliest humans Oldest stone tools pre-date earliest humans Oldest stone tools pre-date earliest humans "Oldest stone tools pre-date earliest humans" "Oldest stone tools pre-date earliest humans" BBC report BBC "Oldest stone tools pre-date earliest humans"