The wolves and moose of Isle Royale have done it again. They've surprised the scientists who have spent more than half a century studying them.
In a journal article published online today in the Proceedings of the Royal Society and in their 2010-2011 annual report, Michigan Technological University researchers John A. Vucetich and Rolf O. Peterson tell an unexpected tale of genetic immigration. In 1997, a virile male wolf crossed an ice bridge from Canada to the remote island national park in northern Lake Superior. He was physically larger than most Isle Royale wolves, and soon after his arrival he became the alpha male of Middle Pack, one of the island's three packs. As he aged, his fur turned very light, a trait that had not been seen previously on Isle Royale, but has since become common. Before knowing his genetic history, the researchers called this wolf "The Old Gray Guy."
How did Vucetich and Peterson learn so much about The Old Gray Guy? For the past 12 years, they had been systematically collecting scat (poop or droppings) deposited by the wolves. The immigrant wolf was discovered after Vucetich and Peterson collaborated with geneticists Jennifer Adams and Leah Vucetich from Michigan Tech and Phil Hedrick of Arizona State University, to examine the DNA contained within the scat. The geneticists found a scat that carried several allelesalternative forms of a genethat had not previously been seen in Isle Royale wolves. Through field observations, Peterson and Vucetich confirmed that this scat belonged to The Old Gray Guy.
"Before this discovery, the Isle Royale wolf population had been considered completely isolated since it was founded in the late 1940s," Vucetich says.
According to the researchers, the discovery is also an important opportunity to better understand genetic rescue, a potentially important conservation tool for populations that suffer from inbreeding. Genetic rescue involves intro
|Contact: Jennifer Donovan|
Michigan Technological University