Bioscience

Dung Happens And Helps Scientists: Scoop On Poop And Climate Change

April 2, 2008

By Flinn Foundation

[Source: ScienceDaily] – When scientists around the world think of dung, they think of Jim Mead.

Mead, a researcher at Northern Arizona University, is one of the world’s foremost authorities on animal dung, and he’s got the poop to prove it.

“You have got to laugh at this bizarre resource,” says Mead, director of NAU’s Laboratory of Quaternary Paleontology. “Although I don’t think anyone is keeping track, I suspect we have the largest comparative animal dung collection in the world. If someone needs to identify dung, they send it to me.”

The lab, part of the university’s Center for Environmental Sciences and Education, has row after row of cabinets with thousands of dung pieces used by scientists to get accurate data on an array of topics, including the environmental changes that took place on the Colorado Plateau during the last 100,000 years.

“Dung is accurate for carbon dating,” Mead explains. “It’s a data set that typically disappears in the fossil record. All we typically get are bones, but with dung we get biochemistry. We can tell a lot about the climate by analyzing what plants the animal ate.”

Through the digested plants, scientists can tell what was going on in the environment at the time, such as the amount of rainfall that was occurring. The data help researchers pinpoint when different changes in the environment took place.

“The plant remains in the dung allow us to determine the mosaic of plants in the local plant community. The community structure changes with changes in climate,” he says.
Mead’s research includes tracking and comparing ancient dung DNA samples to learn about an animal’s gender, food and water sources, air pollen, parasites and community structure during the Ice Age. The data allow him to determine when and how an animal evolved and became extinct.

The collection includes dung from modern animals to prehistoric ground sloths and 40,000-year-old mammoths.

Molecular biologists in Denmark, Australia and Canada are using pieces from NAU’s dung collection to compare its DNA to dung they are finding. “To understand ancient dung, one must have a modern comparative collection, and we have one of the best there is,” Mead notes. “It is extremely rare to have preserved fossil dung