- Who was the first to develop sophisticated
farming methods? The Babylonians? The Mayans? The Chinese? No, no and no.
Try ants.
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- Some kinds of ants have been systematically
growing mushrooms in their nests for 50 million years, according to researchers.
They weed, fertilize and even secrete "herbicides" to combat
pests.
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- Using genetic techniques, ant expert
Ulrich Mueller of the University of Maryland and his colleagues traced
the lineage of mushrooms cultivated by ants in Florida, Panama, Costa Rica,
Trinidad, Guyana and Brazil. Then Mueller compared the lineage of these
'shrooms to those of their wild counterparts.
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- Mueller found that the ants in these
areas are cultivating five very different strains of fungi between them,
suggesting that at some point long ago each of these mushrooms may have
been "domesticated" by different colonies of ants independently
of each other.
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- He and colleagues report their findings
in the latest issue of the journal Science.
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- Previously, many scientists theorized
that ant farming started with one community and then spread each time a
young queen, bringing some fungus with her, started a new colony or nest.
Mueller suspects that ant farming also spread by distantly related ants
sharing their fungus.
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- Mueller's research showed that distantly
related ant species sometimes cultivate the same strain of mushroom. On
the other hand, some species cultivate up to eight different mushroom strains.
In fact, one ant species introduced into Florida earlier this century has
already started cultivating a strain, or "cultivar," originally
farmed by an indigenous species of ant.
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- "This would imply that cultivars
are passed on between ant species quite frequently," Mueller says.
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- Mueller next wants to see if ants' preferences
in mushroom flavors and smells have affected mushroom characteristics.
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- To physiologist Jared Diamond at the
UCLA Medical School, Mueller's approach suggests another idea. He points
out that in addition to growing crops and animals, human farmers have accidentally
"domesticated" the pathogens like measles and smallpox, since
they are mutations of pathogens in farmyard animals.
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- If one were to track the genetic legacy
of these diseases in the same way Mueller tracked the genetic legacy of
the mushrooms, what might it reveal, Diamond asks "about the likely
time and place of origin of these diseases that played so large a role
in human history?"
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- For more News Briefs, and for Feature
Stories, Mind Games, and real-time Expeditions, visit Discovery Channel
Online at http://www.discovery.com
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