Humans love bananas. We eat around 100 billion bananas per year, or 273 million bananas a day. We also grow 1000 or so varieties of bananas — but there’s a catch; one of these varieties, the Cavendish banana, makes up around 50% of global production. Whenever you go to buy a banana, especially if it’s in a supermarket, it’s most likely a Cavendish banana. It’s not the first dominant cultivar, either. Before the Cavendish, we had the Gros Michel banana, which dominated global markets. In the early 20th century, however, the Gros Michel banana was brought to its knees by a fungus: Fusarium oxysp…