GAINESVILLE, Fla. In the complex world of ant-plant partnerships, serial monogamy can help trees maximize their evolutionary fitness, a new University of Florida study shows.
Trees that sequentially partner with multi-species sets of ants produce more offspring than trees that maintain a lifelong association with any single ant even when those sets include ant species that appear to harm the tree, said Todd Palmer, a UF biology professor.
The study has broad implications because many of the world's ecosystems rely on cooperative partnerships between species, Palmer said.
"When you snorkel on a coral reef, you're hovering over an animal the coral that relies heavily on the algae it cooperates with for photosynthesis, just as when you eat an apple, you're reaping the benefits of a tree that was pollinated by an insect," he said.
According to Palmer, many prior studies of cooperation in nature, or mutualism, have focused on the "cheater problem": How can cooperation persist when both sides have an incentive to reap benefits without contributing to the common good? Ecological studies tend to be short-term, with species labeled as "cooperators" or "freeloaders," depending on cost-benefit ratios calculated over just a few years.
Palmer and his team took a different approach, looking at a common African tree and its relationships with four specialized ant partners over the tree's lifetime.
The surprising finding was that the tree in Kenya did best when occupied by all four ant species over its lifetime, even though one ant species joined forces with beetles in ways that increased tree death rates; another sterilized the tree; and a third was so scared of the other three competing ant species that it didn't do much of anything, said Palmer, whose paper is published this week online in Proceedings of the National Academy of Sciences.
"Looking at the costs and benefits to the tree, not just at a si
|Contact: Todd Palmer|
University of Florida