GENETICS & APPLIED ECOLOGY
DNA: Code of the Wild

Program Summary

Download a PDF version of the transcript.

Producer: Barrett Golding
Low-Mow Lawns Feature Producer: Erik Anderson
On the Air Beginning: November 2001

Ecology is the study of whole living systems. Biologists who study how plants, animals, microbes and other living things interact are using genetics as a powerful new tool.

What they're learning has many applications, including wildlife conservation, planning park boundaries, and saving endangered species. Scientists are also using DNA as a tool to create new life forms in order to clean up toxins in the environment.

In this program, we learn how scientists are applying DNA tools to ecology.

In Yellowstone National Park, scientists study populations of grizzly bears to see if they are getting too inbred for their long-term survival. They are using mitochondrial DNA (genetic material in the energy-producing part of the cell) to study different family lines of bears and to map their movements throughout the park over time.

Their research has led to a plan to connect the Yellowstone bears with other populations of grizzlies to the north, in Canada, through setting aside large tracts of protected land to act as a corridor.

Steve Palumbi is using DNA techniques to understand ocean wildlife. Among his projects, he is applying the same forensic techniques used in crime scenes to track down whale poachers.

In Monterey, California, Ed DeLong heads a team that studies marine life of the smallest type: ocean-dwelling microbes. The DNA in these tiny life forms is helping scientists redraw the tree of life. From studying certain genes, researchers are able to figure out evolutionary relationships that had been previously unknown.

Jo Handelsman studies soil microbes, many of which have never been classified. She says these tiny creatures are so important, without them whole ecosystems would come crashing down. In their own micro-ecosystem, an array of interactions is going on all the time. Microbes are eating other microbes, injecting each other with viruses, and generally carrying on in their own very small world.

The fields of phytoremediation and bioremediation look to genetics to help harness nature to clean up nature. At the Savannah River Nuclear Power plant, ecologist Travis Glenn is studying mutations in alligators living in water contaminated by low-level radioactive waste. Norman Terry studies the humble weed Arabidopsis, or wild mustard, in hopes of finding a gene he can use to prompt wetland plants to absorb toxins such as selenium.

Other biologists are engineering microbes to clean up toxic waste such as lead and mercury. Gary Sayler has created "critters on a chip," or microbes on a small glass slide that glow when they are eating chemical contaminants.. Others scientists hope to harness the powers of superbugs like D. radiodurans, a microbe that can live in high-radiation environments.

While none of these bugs are out of the lab yet, they are already raising important questions. What kind of ecological problems might we be creating in trying to clean up the planet with genetically-modified organisms, or GMOs? What happens if a metal-eating microbe multiplies beyond its target cleanup site? What if it swaps genes with another microbe?

When Aldo Leopold wrote in the historic Sand County Almanac, "To keep every cog and wheel is the first precaution of intelligent tinkering," he probably never imagined we would be able to rewrite the code of life - with so little knowledge of the outcome.

Special Feature: Low-Mow Lawns

Scientists at Scotts Company are developing a strain of genetically-altered turf grass that grows more slowly and needs less mowing. What are the risks and benefits of such a product? Could the non-growth gene spread to native grasses? Should the new turf grass be regulated like a food crop?

Topic In-Depth: Are ethics and safety equal?

Last Updated: July 2004