In a paper published today, they argue that "female orgasm" is an evolutionary holdover from an ancient system. ... https://www.google.com/search?q=evolutionary+holdovers&client=opera&source=lnms&sa=X&ved=0ahUKEwiHoqmetYrWAhVQ22MKHWbQDWMQ_AUICSgA&biw=1342&bih=847&dpr=1