The relationship between ants and their cultivated fungi is so finely tuned that ants actively manage their fungal gardens. Like human farmers, they weed out harmful bacteria and fungi, transferring healthy fungal matter to fresh patches to encourage growth. Some ant species even carry bacteria that produce natural antibiotics, helping to protect their crops from diseases.
“Somehow, over the course of 66 million years, they’ve been able to continue to control crop disease and develop antibiotics that continue to be effective,” Schultz shared. “We’ve only been using antibiotics and herbicides for less than 100 years and we have major problems keeping up with resistance and developing new antibiotics.”
This groundbreaking study is the culmination of Schultz’s 35 years of research into the ant-fungus relationship. His team collected thousands of genetic samples from Central and South America to create the largest-ever genetic dataset of fungus-farming ants. By comparing wild fungal species with those cultivated by ants, researchers concluded that these insects began farming fungi shortly after the asteroid impact that marked the end of the Cretaceous period.
While the extinction event was disastrous for many species, it opened new ecological niches for others. “What was a catastrophe for some organisms 66 million years ago was a golden era for others,” Schultz explained. “Photosynthesis was shut down by the asteroid, and a bunch of plants were driven to extinction. But some fungi grow in decaying plant matter—it was a great time for them.”
This abundance of fungi likely attracted ants, who recognized fungi as a reliable food source. Over time, as climates shifted and the world changed, some ant species adapted their farming practices to suit drier, more arid environments. This led to the development of what researchers call “higher agriculture,” in which ants isolated their fungi from wild populations, creating a mutual dependency. This ancient agricultural relationship between ants and fungi continues to flourish today, offering new insights into evolutionary biology and sustainable farming practices.