Fungus-farming ants cultivate multiple species of fungi for food, but the history of fungus-ant co-evolution is poorly known. In a new study published this week in the journal Science, researchers found that fungus-ant agriculture originated approximately 66 million years ago when the end-of-Cretaceous asteroid impact temporarily interrupted photosynthesis, causing global mass extinctions but favoring the proliferation of fungi.
Nearly 250 different species of ants in the Americas and Caribbean farm fungi.
Entomologists organize these ants into four agricultural systems based on their cultivation strategies.
Leafcutter ants are among those that practice the most advanced strategy, known as higher agriculture.
These ants harvest bits of fresh vegetation to provide sustenance for their fungi, which in turn grow food for the ants called gongylidia.
This food helps fuel complex colonies of leaf cutter ants that can number in the millions.
“Ants have been practicing agriculture and fungus farming for much longer than humans have existed,” said Smithsonian Institution entomologist Ted Schultz.
“We could probably learn something from the agricultural success of these ants over the past 66 million years.”
“We believe decaying leaf litter likely became the food of many of the fungi that grew during this period, which brought them in close contact with ants.”
“The ants in turn began to use the fungi for food and have continued to rely on and domesticate this food source since the extinction event.”
“To really detect patterns and reconstruct how this association has evolved through time, you need lots of samples of ants and their fungal cultivars.”
In the research, Dr. Schultz and colleagues analyzed genetic data from 475 species of fungi and 276 species of ants to craft detailed evolutionary trees.
This allowed the researchers to pinpoint when ants began cultivating fungi millions of years ago, a behavior that some ant species still exhibit…
Read the full article here