Fungi-cultivating ants cultivate multiple species of fungi for food, but little is known about the history of coevolution between fungi and ants. in new research Published in this week's magazine scienceresearchers found that mushroom and ant agriculture began about 66 million years ago, when an asteroid impact at the end of the Cretaceous period temporarily disrupted photosynthesis and caused a global mass extinction, but mushroom proliferation continued. It was discovered that it promoted
Rare fungi-cultivating ants and lower fungi-cultivating ant workers. mycetophylax aspercollected in 2014 at a mycological garden in the state of Santa Catarina, Brazil. Image credit: Don Parsons.
About 250 different species of ant farm fungi from the Americas and the Caribbean.
Entomologists classify these ants into four farming systems based on their cultivation strategies.
Leafcutter ants are among the most sophisticated ants that practice a strategy known as high agriculture.
These ants harvest fresh plant parts to feed the fungi, which in turn grow food for the ants called gondilidia.
This food helps leaf-cutter ants form complex colonies that can number in the millions.
“Ants have been farming and cultivating fungi for far longer than humans have been around,” said Ted Schultz, an entomologist at the Smithsonian Institution.
“Perhaps we can learn something from the agricultural success of these ants over the past 66 million years.”
“We believe that the rotten leaves provided food for many of the fungi that proliferated during this period, which may have brought them into close contact with the ants.”
“Ants, in turn, began to use the fungi as food, and have continued to rely on and domesticate this food source since extinction.”
“We need large samples of ants and their fungal varieties to actually detect patterns and reconstruct how this association has evolved over time.”
In the study, Dr. Schultz and his colleagues analyzed genetic data from 475 species of fungi and 276 species of ants to create a detailed evolutionary tree.
This allowed researchers to pinpoint when ants began cultivating fungi millions of years ago, a behavior that some ant species still exhibit today.
“Historical thinking about fungi farming by ants generally assumed a single origin for fungi farming, but this provides deeper insight into the question of how ants got started with fungi farming. What was holding us back was trying to get enough DNA sequence data from the fungi that the ants consumed.”
“Over the past 15 years, the cost of genome sequencing has fallen significantly and the technology for collecting many types of genomic data has improved significantly, making this and many other studies possible.”
“If you have a mushroom, it's relatively easy to sequence its genome.”
“However, given the tiny fragments of fungi that ants carry inside their bodies, it is difficult to obtain enough fungal material to generate enough genome sequence data for analysis. So the fungi we created Now comes the bait set.”
“Thanks to them, it is now possible to extract, amplify, sequence, and analyze DNA from tiny fungi.”
The data reveals that ants and fungi have been intertwined for about 66 million years. This was around the time an asteroid hit the Earth at the end of the Cretaceous period.
This massive impact filled the atmosphere with dust and debris, blocking the sun and preventing photosynthesis for years.
The resulting mass extinction wiped out about half of all plant species on Earth at the time.
But this disaster was a boon for fungi. These creatures multiplied by consuming large amounts of dead plant matter scattered on the ground.
“While extinction events can be catastrophic for most organisms, they can actually be beneficial for others,” Schulz said.
“At the end of the Cretaceous period, dinosaurs weren't really thriving, but fungi were at their peak.”
The study also revealed that it took nearly 40 million more years for ants to develop advanced agriculture.
The authors were able to trace the origins of this advanced practice back to about 27 million years ago.
Around this time, the environment around the world changed due to rapid cooling of the climate.
In South America, drier habitats such as wooded savannahs and grasslands have broken up vast swaths of moist tropical forest.
When ants took fungi out of humid forests and moved to drier areas, they isolated them from their wild ancestral populations.
The isolated fungi became completely dependent on ants to survive in dry conditions, setting the path for the advanced agricultural systems practiced by leaf-cutter ants today.
“Ants domesticated these fungi in the same way that humans cultivate crops,” Dr. Schultz said.
“What's amazing is that we can determine when higher ants first cultivated higher fungi.”
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Ted R. Schulz others. 2024. Coevolution of fungi and ant agriculture. science 386 (6717): 105-110;doi: 10.1126/science.adn7179
Source: www.sci.news
