How a lone 'immigrant' wolf revived a forest ecosystem

In 1997, a lone wolf crossed an ice bridge that briefly connected Canada with the remote Isle Royale, which lies off the coast of Michigan in Lake Superior and is renowned for its rich biodiversity. His arrival revived the flagging fortunes of the wider wolf population, which had been hit by disease and inbreeding, and triggered cascading effects that improved the health of the overall forest ecosystem, a study in Science Advances showed Wednesday. "Issues like inbreeding and low genetic diversity are an important concern for scientists," first author Sarah Hoy, an ecologist at Michigan Technological University told AFP. Enter the immigrant, identified as "M93" by scientists, but affectionately nicknamed "The Old Gray Guy." By 2008, two years after his death, 60 percent of the wolf population's gene pool was inherited from M93, which led to a return of genetic deterioration.