Flowers are pretty so they will attract animals, such as birds and bees, who are crucial for pollination. New data uncovered by researchers at Indiana University Southeast suggests this showy form of reproduction has been dominant among flowering plants for a very long time.

Shusheng Hu, an IU Southeast research associate, and David Winship Taylor, IU Southeast biology professor, joined forces with David L. Dilcher and David M. Jarzen, both from the Florida Museum of Natural History at the University of Florida, to examine the origin of flowering plants and how they reproduce. The group's findings are featured in the scientific journal Proceedings of the National Academy of Sciences.

In the study, fossilized flowers showed that animals have been helping plants reproduce since ancient times. New data uncovered by the IU southeast researchers suggests that 76 percent of the first flowering plant species were insect pollinated, while only 24 percent were pollinated by the wind.

To help support their theory, the botanists studied the specialization of fossil pollen in Minnesota and discovered that many species of pollen were clumped. Clumped pollen is found only in animal-pollinated flowers.

Trying to figure out interactions between fossil organisms is difficult. "We provided a new method (looking at clumped fossil pollen), and it supported the previous hypothesis that the first flowers were insect pollinated," Taylor says.

The research also suggested that pollen from those plants that were wind-pollinated may have been the source of prehistoric allergies. Wind pollinated plants are the main source of allergies in people, and many researchers now believe that wind-pollinated plants may have caused allergic reactions in dinosaurs and other animals.

The researchers will continue to look at older localities of plant species, according to Taylor. Meanwhile, the methods used by the IU Southeast researchers are opening up a new area of pollination biology.

"We will be presenting these new data at a meeting of the International Organization of Paleobotanists in Bonn, Germany, in August and will contribute a chapter to a symposium volume," Taylor says. "We expect it will open a new area of pollination biology research."

For more information and a complete report, visit the Early Edition of Proceedings of the National Academy of Sciences at www.pnas.org.