April 17 NOVA show featuring UF-Chinese research traces evolution of flowers

April 9th, 2007

Photos available

GAINESVILLE, Fla. — Joint research between Florida Museum of Natural History and Chinese scientists to discover and interpret the world’s earliest known flowering fossil is the subject of a PBS NOVA documentary, “First Flower,” which debuts at 8 p.m. April 17.

The origin of flowers is one of botany’s deepest mysteries, and in the NOVA documentary, Florida Musuem paleobotanist David Dilcher guides viewers through segments of the amazing story of the evolution of flowers.

“There’s no doubt about it, flowers are all about sex,” said Dilcher, a graduate research professor and paleobotany curator at the Florida Museum and a member of the National Academy of Sciences.

The search for the world’s first flower drew Dilcher to a remote Chinese lake where colleague Sun Ge of Jilin University in Changchun, China, discovered a 125 million-year-old fossil that scientists believe is the earliest known flower.

Although the fossil lacked the aesthetic petals associated with modern flowers, Dilcher recognized the plant stalk had seeds enclosed within carpels, which are female reproductive structures found in flowers. This led him to conclude the fossil was in fact an early form of a flower. The fossil was named Archaefructus liaoningensis, which means “ancient fruit from Liaoning Province of northeast China.”

Flower production demands an amazing amount of a plant’s precious energy, which leads some scientists to question why and how the world’s first flowers evolved. Angiosperms, or flowering plants that have male pollen and female ovaries, are thought to have made their first appearance on earth roughly 130 million years ago. Today, they dominate the plant world. Today, bees, moths, hummingbirds and other insects facilitate plant reproduction by spreading pollen, but this is the culmination of a complex relationship that evolved over millions of years and that scientists are still decoding.

“Flowering plants were the first advertisers in the world,” Dilcher said. “They put out beautiful colors, colorful patterns, they put out fragrances. And they gave a reward such as nectar or pollen for any insect that would come and visit them.”

Flowers go to elaborate lengths to advertise their sexual organs, the female parts and the male parts, Dilcher said.

“If they could attract these mobile pollinators to visit, crawl around, and feed in flowers, pick up pollen on their legs, pick up pollen on their bodies,” Dilcher said, “and then fly to another flower some distance away, and repeat this process, they could effectively transfer their male genetic material some distance away to another flower.”

Pamela and Doug Soltis, Florida Museum researchers who study plant and flower DNA to better understand evolutionary origins, also are interviewed in “First Flower.” The Soltis’ work addresses evolutionary origins of flowers and flowering plants, plant speciation and the conservation genetics of endangered plant species in Florida. Doug Soltis also is chair of UF’s Department of Botany.

The journal Science featured Sun’s and Dilcher’s fossil flower research on its cover in 1998 and 2002. Sun is a geologist and director of the paleontology and stratigraphy lab at Jilin University. Dilcher holds professorial appointments and teaches at Jilin University and Nanjing University in China, in addition to teaching at the University of Florida.

Writer: DeLene Beeland
Media contact: Paul Ramey, pramey@flmnh.ufl.edu

Source: David Dilcher (352) 392-1721 ext. 460
Source: Sun Ge (352) 392-1721 ext. 460; until April 12