Can animals evolve quickly enough to survive global warming?

  • Michelle Nijhuis

 

In recent years, Westerners have seen and heard a great deal about the effects of climate change on wildlife. Pikas are increasingly isolated on shrinking islands of mountaintop habitat in the Great Basin; mice, chipmunks and squirrels are retreating toward the ridgelines of Yosemite National Park; and numerous species, from butterflies and hummingbirds to an array of mammals, appear to be shifting uphill and northward.

The evidence has sparked a lively and emotional debate among conservation scientists. When threatened species can't relocate to more hospitable habitats, should we move them ourselves? The idea, known as "assisted colonization" or "assisted migration," is controversial for a lot of reasons, but a growing number of researchers see it as a necessary conservation strategy for at least some species.

As part of "Hot Times," our continuing series on climate change and the West, Hillary Rosner examines other strategies available to Western wildlife -- and to conservationists. Some species may be able to adapt to their changing habitats, either by simply tolerating new conditions or by evolving quickly enough to survive them. "Evolution is not just about one species ever-so-slowly transforming into another," Rosner writes. "It's also about much smaller, much faster changes that can determine whether a species will endure or perish as its world shifts."

Late last year, Rosner accompanied Montana biologist Scott Mills and his students into the Seeley-Swan Valley, where Mills studies seasonal coat color changes in snowshoe hares. For hares, coat color is a matter of survival: Brown hares on snowy ground and white hares on brown ground are both easy pickings for predators. In recent years, hunters and other observers have reported increasing numbers of hares out of sync with the season. But by tracking a group of Seeley-Swan hares throughout the year, Mills is finding that individual animals may be able to adjust the rate of their coat change to match variations in snowfall -- literally outfitting themselves for survival in a changing world.

For the hares, it's hopeful news. For us, it raises some new -- and sticky -- questions. If evolution can occur rapidly enough to protect some species from climate change, do conservationists have a responsibility to practice so-called "evolutionary rescue"? That is, should they encourage the reproduction of especially adaptable individual animals, or introduce resilient subspecies into new habitats? There are countless questions, both scientific and ethical, and no clear answers.

It's easy, and tempting, to say that humans have meddled enough, and that natural systems should simply be left alone to adapt as well as they can. But our power over the West's climate and habitat, for both good and ill, is outsized and growing. We can pursue answers to the many questions raised by climate change, and do our best to direct our influence intelligently. But stepping back is not an option.

Note: the opinions expressed in this column are those of the writer and do not necessarily reflect those of High Country News, its board or staff. If you'd like to share an opinion piece of your own, please write Betsy Marston at [email protected].

High Country News Classifieds
  • LAND CONSERVATION MANAGER
    SUMMARY Leads, administers and manages the land conservation, conservation easement stewardship, and property management activities of the City of Fort Collins Natural Areas Department within...
  • CLEAN ENERGY PROGRAM ATTORNEY, NEVADA
    Position Summary: Western Resource Advocates (WRA) is seeking a Staff Attorney who is passionate about Western communities and the protection of the natural environment to...
  • EXECUTIVE DIRECTOR
    Deschutes River Conservancy in Bend, Oregon
  • WATER POLICY ANALYST WITH WRA (BOULDER)
    Position Summary: Western Resource Advocates seeks a passionate Water Policy Analyst with knowledge of western water issues to join our Healthy Rivers Team to strengthen...
  • GILA NATIONAL FOREST
    9+ acre inholding. Passive solar strawbale off the grid and next to the Continental Divide Trail in ponderosa pine/doug fir forest at 7400.
  • HIRING BEARS EARS EDUCATION CENTER DIRECTOR
    Conservation nonprofit Friends of Cedar Mesa in Bluff, Utah is hiring an Education Center Director to oversee the operation of the Bears Ears Education Center....
  • PROGRAM MANAGER, SUSTAINING FLOWS
    Friends of the Verde River, Cottonwood, AZ. Apply at https://verderiver.org/employment-opportunities/
  • PROGRAM ASSOCIATE - VERDE RIVER EXCHANGE
    Verde River Exchange - Friends of the Verde River, Cottonwood, AZ. Apply at https://verderiver.org/employment-opportunities/
  • CODE COMPLIANCE OFFICER
    Teton County Planning & Building is hiring! Our ideal candidate is a team-player, a problem-solver, pays attention to detail, and can clearly communicate technical material...
  • ARCHITECTURE DRAFTSPERSON/PROJECT MANAGER
    Studio Architects is seeking a full time Architectural drafts-person/project manager with1-3 years of experience to join our firm. At Studio Architects our mission is to...
  • ASSISTANT MANAGER/TRAINEE, COLORADO RANCH
    needed for 16,000+ acre conservation property in south central Colorado. Qualified candidate would have experience working on a ranch or wilderness property, general forestry/fire management...
  • FARM HAND &/OR NANNY IN ESCALANTE
    Nanny for 18-mnth-old. Yearly salary, vacation, health insurance. Spanish/other foreign-language native spkr prefrrd.
  • EXECUTIVE DIRECTOR
    Washington Association of Land Trusts seeks an ED to build on WALTs significant success & to lead the association to new levels of achievement. See...
  • BEAUTIFUL CUSTOM STRAWBALE HOME IN WESTERN COLORADO!
    Secluded, energy efficient Southwestern home on 40 wooded acres. Broker - Rand Porter - United Country Real Colorado Properties. 970-261-1248, $425K
  • FORMER RETREAT CENTER/CONSERVATION PROPERTY FOR SALE
    57 acres in Skull Valley, AZ, 17 miles from Prescott, year-round creek, swimming holes, secluded canyon, hiking/meditation trails, oaks, pines, garden, greenhouse. House, office building,...
  • ARIZONA PUBLIC LANDS ORGANIZER
    Title: Public Lands Organizer About the Arizona Wildlife Federation (AWF) The AWF is a non-profit organization dedicated to educating, inspiring, and assisting individuals and organizations...
  • HISTORIC RANCH HOME W/ 20 ACRES
    Historic 1893 Ranch Headquarters. 4 Bdrm, 3.5 Ba, 4000 ft2. Remodeled 2002. Includes 2 studio apts, stables, arena, workshop, 5 RV hookups. Chirachua & Peloncillo...
  • VICE PRESIDENT OF RETAIL OPERATIONS
    The Vice President of Retail Operations will provide overall leadership and accountability for purchasing, product development, merchandising planning, visual merchandising, retail operational excellence, oversight and...
  • ASSOCIATE DIRECTOR
    Grand Staircase Escalante Partners seeks an experienced fundraiser with excellent communication and organizational skills.
  • PROGRAM MANAGER
    position in Phoenix with the Babbitt Center for Land and Water Policy.