Peer-Reviewed Study by NRDC Scientist Reveals Problems in the Use of Genetic Studies by Federal Wildlife Agencies

Lack of Federal Guidelines Results in Questionable Studies with Outsized Influence
WASHINGTON, DC (September 20, 2007) – A new study published today in the journal Conservation Biology shows that genetic studies can have dramatic effects on decisions to protect imperiled wildlife under federal law, and warns that agencies deciding the fate of such species lack any guidelines to help them separate good genetic studies from those that are less reliable.
The study’s findings raise serious concerns over the influence that genetic data has on wildlife protection decisions made under the federal Endangered Species Act.
The study, authored by Dr. Sylvia Fallon, a molecular ecologist and Science Fellow with the Natural Resources Defense Council (NRDC), reviewed nearly 40 listing decisions by the U.S. Fish & Wildlife Service and the National Marine Fisheries Service over a 10 year timeframe that utilized genetic information to determine whether plants and animals qualified for protection under the U.S. Endangered Species Act.
Dr. Fallon’s study reveals wide variation in both the quality and quantity of data relied on by federal agencies. Specifically, studies that used less data were much less likely to identify genetic distinctions than those that used more data. The study also found endangered species listing decisions often relied on too little information. The fact that genetic data varies widely between endangered species listing decisions suggests that not all organisms receive equal consideration during their evaluations.
“It’s catch as catch can. The agencies typically don’t have the resources to conduct or commission genetic studies themselves,” Dr. Fallon said. “Instead, they are examining whatever happens to be available in the literature. This leads to wide variation in the quality and quantity of genetic data that is evaluated for each organism and could have the potential to misguide the agencies’ conclusions.”
Genetics has played a key role in several controversial Endangered Species Act decisions, such as the case of the Northern Spotted Owl and more recently the Preble’s meadow jumping mouse, which is found in Colorado and Wyoming.
Much is riding on the quality of this genetic research. Dr. Fallon found that species were given protection under Endangered Species Act in 80 percent of the cases where studies identified genetic distinctions between groups of organisms. In cases where genetic studies failed to find a distinction, protection was denied 80 percent of the time.
What’s more, the Endangered Species Act requires that the agencies base their decisions on the best available science. In practice, this means that if there is only one study available, it will be considered the best science regardless of its quality.
“The problem is that genetic data is often considered the silver bullet of biological information and may trump other types of data like ecology, geography or behavior,” Dr. Fallon said. “Agencies need to recognize that the results of genetic studies are only as good as the underlying data, which in some cases may not be good at all.”
A copy of the study, Genetic Data and the Listing of Species Under the U.S. Endangered Species Act,is available online to subscribers at