Genetics & Applied Ecology: DNA: Code of the Wild

PRODUCERS: Barrett Golding


New & Noteworthy, 2007
by Jennifer Jongsma

In DNA: Code of the Wild, The DNA Files looked at the ways in which genetic technologies have helped us to understand ecology and manage environments. In 2001, scientists were already taking advantage of the vast number of genetic tools available for tasks ranging from forensic testing of animals on the brink of extinction to identifying illegal whale meat for sale.

Since then, there have been many more applications of genetics and DNA to ecological problems. In 2007, the U.S. Fish and Wildlife Service removed the Yellowstone population of grizzly bears from the endangered species list, based in large part on the information on sex ratios, genetic variation, and relatedness of individual bears gathered by the U.S. Geological Survey's Interagency Grizzly Bear Study Team. However, four other grizzly populations in the lower 48 states have not yet recovered and remain on the endangered and threatened species list. Another successful application of genetic tools is the recovery of the California Condor. The California Department of Fish and Game has carefully managed its captive breeding program to prevent the loss of genetic diversity. The population of condors has gone from 27 in 1983 to more than 273 in 2005.

In whale meat markets, scientists are finding less illegal meat for sale. However, the definitions of illegal are changing. The Japanese government recently added a few individuals of a wide variety of species to its list of allowable hunted animals, so it is more important than ever for researchers to apply genetic tests to discover the source(s) of the meat. Genetic testing offers the best way to verify if a product in the marketplace is a legal species or if it is from an endangered species.

Owing to the breadth of ecologically pertinent data and its highly diverse nature, a new field has emerged within ecology. Bioinformatics, the application of computational tools to the management and analysis of biological data, is allowing researchers to access an ever-broader array of data. Scientists can share information from evolutionary studies on the microscopic E. coli to data on the Earth's biosphere. In 2001, John Avise said, "I fully anticipate that within the next 20 years that entire tree of life will be illuminated almost completely." The entire tree isn't illuminated yet, but there are many more lights shining on it.

Original Program Description, 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.