But even if life on earth turned out to have a nonevolutionary origin ( for instance , if aliens introduced the first cells billions of years ago ) , evolution since then would be robustly confirmed by countless microevolutionary and macroevolutionary studies 但是,即使地球上的生命有個(gè)與演化無(wú)關(guān)的起源(例如,最早的細(xì)胞是幾十億年前外星人送到地球上來(lái)的) ,對(duì)于生命出現(xiàn)以后的歷史,演化依舊會(huì)是鐵案如山的解釋,有無(wú)數(shù)微演化與巨演化研究產(chǎn)生的證據(jù)支持。