Natures wonders: ants farm fungus for food II (Introduction)

by David Turell , Wednesday, May 09, 2018, 22:26 (2388 days ago) @ David Turell

More information about leafcutter ants:

https://www.sciencedaily.com/releases/2018/05/180509104921.htm

"Leafcutter ants are found only in the Americas. More than 40 species range from Argentina to the southern United States, and they are a dominant ecological player in any forest or grassland they inhabit.

"'They aren't the only ants that grow fungi, but if you compare leafcutter ants with other ants that grow fungi, there are many differences," Mueller said. "For starters, no other ants use freshly cut leaves to grow their fungi."

"Ants that grow fungus on dead and decaying leaves have been around even longer than leafcutters, probably about 50 million years, Solomon said. But leafcutters' ability to use living leaves was a quantum leap in evolutionary terms because it opened up the entire ecosystem. For example, Solomon said, the ability to consume plant matter they cannot directly digest allows a nest of leafcutters to consume about as much vegetation each year as a full-grown cow.

"'Once you can use fresh leaves, it gives you access to so much more food," Solomon said. "If you can grow and raise your crop on any leaf that's growing out there, then the sky's the limit."

"In comparison with other fungus-growing ants, leafcutter colonies are enormous, Solomon said.

"'They're on the order of millions of individuals. Some leafcutter colonies are so large that they show up on photos taken by satellites in space."

Leafcutters also have specialized tasks. Individual worker ants come in different sizes, and they have different jobs.

"'Some are specialized on raising the young," Solomon said. "Others are specialized on removing weeds and disease inside the nest. Others are specialized on going out and finding food, and yet others are specialized on defending the colony.

"'All of the specialization is unique to the leafcutters," he said. "With other fungus-growing ants, the workers are basically interchangeable. They don't have these specialized tasks.

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"'We sampled tons of different nests of leafcutter ant species throughout the entire range of all leafcutters, which goes from Texas in the extreme north down to Argentina," Solomon said. "What's novel about our approach is how much sampling there was, particularly in South America. In the past, there has been a lot of sampling, but it was focused in just a few different regions, particularly in Costa Rica and Panama.

"'It turns out the leafcutters in those places don't represent species that live elsewhere," he said. "By going and sampling in other places, especially in the open grasslands of southern Brazil, Paraguay and northern Argentina, we were able to show that the greatest genetic diversity of leafcutter fungi is in South America. Usually, wherever there's the greatest genetic diversity is where a group originated. That is true for humans, and that's just generally true of other species, and that leads us to believe the leafcutters originated in the grasslands of South America.'"

Comment: Since the workers have assigned jobs they work automatically, but this still doesn't explain how ant colonies like this work out such a specialized farming lifestyle. Since many other ants raise fungus on dead leaves, it can be assumed ants like the taste of fungus as food and learned to work out a way of farming as an instinct. Of course, perhaps God helped.