On Friday 21st April, Thomas Hitchcock gave a short talk at Nerd Nite Tokyo entitled “Sex Education: reproductive diversity across the tree of life”. There he talked to a general audience about the range of ways that organisms may reproduce, from those organisms that simply make copies of their own genes (asexual reproduction), to those that mix them with others (sexual reproduction), and those that can do both (facultative sex). He discussed the different mechanisms that organisms may use to decide whether to reproduce as a female (producing eggs) or male (producing sperm), and how genes may pass differently to offspring through these two routes, illustrating these ideas with stories about spoonworms, fungus gnats, and rotifers. Finally, he stressed how evolution may work differently in these different reproductive systems, and so the importance of understanding this diversity for guiding our efforts in conservation, agriculture, and medicine.