Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Poop Reveals an Immigrant in Isle Royale Wolves' Gene Pool

01.04.2011
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 alleles—alternative forms of a gene—that 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.

The research was funded by the National Science Foundation (NSF) and the US National Park Service.

“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 introducing one or more unrelated individuals into an inbred population. The effectiveness of genetic rescue is not well understood because the opportunities are limited to closely monitor an isolated population before and after a known immigration event. For this reason, the Isle Royale immigrant represents a special opportunity.

Genetic rescue is supposed to result in increased survival or reproduction. However, evidence for increased birth or longevity rates in the Isle Royale population is equivocal. Coincident with the immigrantʼs arrival, though, moose on Isle Royale declined dramatically in response to food shortage, severe winters and tick outbreaks. A clear response to the immigration event may well have been disguised by lack of food for the wolves, the scientists suggest. If so, it may be important to recognize that deteriorating ecological conditions can mask the beneficial effects of infusing new genetic material, they point out.

The Old Gray Guy died in 2006. But he left his mark. He sired 34 offspring and 22 grand-offspring, “and counting,” the scientists say. Today, 56 percent of all the genes now found in the Isle Royale wolf population trace back to him. Within a couple of generations of the Old Gray Guy’s arrival, inbreeding plummeted, but then rose quickly again. This Isle Royale case shows how the effect of genetic rescue can be substantial and manifest quickly, but also be short-lived.

Wolf Population Declining

The wolf-moose researchers’ latest report also brings discouraging news about the wolves of Isle Royale. This year’s Winter Study, conducted between Jan. 12 and Feb. 28, 2011, found that the Isle Royale wolf population had been reduced to just 16 wolves. Among these wolves are no more than two adult females. If the few remaining females were to die before raising female pups, the wolf population would almost certainly be committed to extinction. “The situation is kind of precarious,” says Vucetich. “But it’s always been precarious,” Peterson notes.

The wolf population has also been reduced from the four packs seen a couple of years ago to perhaps just a single pack. East Pack and Paduka Pack went extinct in late 2009. In late February 2011, Chippewa Harbor Pack traveled deep into Middle Pack’s territory, where they killed Middle Pack’s alpha male (a son of the Old Gray Guy). “With his death, the survival of Middle Pack is doubtful,” Vucetich and Peterson say. It has been 40 years since the wolf population was comprised of just a single pack.

The scientists acknowledge that National Park Service (NPS) policy promotes natural processes, and that, in this instance, local application of NPS policy could mean natural extinction. However, they advocate for an evaluation of the full range of management options, including the introduction of new wolves into the inbred population on Isle Royale.

Moose are Thriving

During the 2011 Winter Study, the scientists estimated a population of 515 moose, approximately the same as it has been for the past three years.

With the number of moose remaining low for so long now, the vegetation on Isle Royale also has become more abundant. Balsam firs, a favorite meal for moose, are growing taller than ever before, and deciduous shrubs have been flourishing. The calves were larger this winter, and the fat content of bone marrow indicates that adult moose are better nourished now. The scientists have spotted three sets of twins in the past two years, the first twins since 2005. Winter ticks, which posed a severe threat to the Isle Royale moose in 2007, have declined significantly since then.

“The moose are poised for increase,” says Peterson. The last large increase in the moose population was seen on Isle Royale in the 1990s.

Michigan Technological University (www.mtu.edu) is a leading public research university developing new technologies and preparing students to create the future for a prosperous and sustainable world. Michigan Tech offers more than 130 undergraduate and graduate degree programs in engineering; forest resources; computing; technology; business; economics; natural, physical and environmental sciences; arts; humanities; and social sciences.

Jennifer Donovan | EurekAlert!
Further information:
http://www.mtu.edu

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>