The secret of success may be in the genes.

A decade after wolves were reintroduced to Yellowstone National Park, a UCLA researcher is studying the wolves' DNA to better understand how genetics and family ties influence where they live, with whom they mate and how they choose their friends.

"We're trying to understand, in a sense, the secret soap opera of wolves in Yellowstone," said Robert K. Wayne, professor of biology and co-founder of UCLA's Conservation Genetics Resource Center.

The project, expected to be completed later this year, also could help wildlife managers if they try to reintroduce other species in the future.

"Most reintroductions don't succeed," Wayne said.

But since 31 wolves were reintroduced to Yellowstone in 1995 and 1996, the population has grown beyond expectations. There are about 170 wolves in the park, 300 in the Yellowstone ecosystem and more than 800 in Montana, Idaho and Wyoming.

Wayne is looking for the possible genetic basis of the program's success. Specifically, he'll look at how family ties between wolves affect the establishment of packs, roaming patterns, mating and rivalries with other packs.

In Minnesota, the second leading cause of wolf mortality is aggression between packs. Yellowstone also has interpack fights, especially on the Northern Range where packs are clustered closer together.

Wayne said researchers want to find out whether the level of aggression between wolves is connected to their kinship.

So far, more than 500 blood samples have been taken from wolves in Yellowstone and outside the park's borders in Montana, Wyoming and Idaho. Through genetic analysis, researchers hope to create a sort of family tree for Yellowstone wolves over the past 10 years.

It helps that the wolves have been watched so closely.

In most cases, researchers know who the founding wolves of Yellowstone were, what happened to their descendants and the general dynamics of the population, Wayne said.

That information will contribute to a more complete picture of Yellowstone's wolves and the genetic messages they carry.

"This is the most comprehensive genetic analysis of North American carnivores ever undertaken, and involves the most notable U.S. population," Wayne said.

The work is being done under a contract awarded by the U.S. Fish and Wildlife Service and the Yellowstone Park Foundation in August.

Among other things, it will help determine whether there is sufficient gene flow between wolf populations, a point that could influence whether wolves in the Northern Rockies are removed from the endangered species list.

"This is an unprecedented opportunity to address behavioral, ecological and conservation questions in what is arguably North America's premier carnivore," Wayne said.