Science Evolves

While evolution often evokes thoughts about ancient origins of life, University of Maine researcher Michael Kinnison says applied evolutionary biology is about improving the future — including pressing matters of day-to-day life and issues of international policy.

A paper by lead authors from the University of Copenhagen and the University of California, Davis, as well as Kinnison, highlights ways in which food security, human health and biodiversity can benefit in the short- and long-term by using principles of evolutionary biology.

The paper published online Sept. 11 at Science Express indicates when evolution is overlooked the prevailing approaches to treat human disease, reduce agricultural pests and manage at-risk wildlife can be detrimental to achieving sustainable solutions and exacerbate the very problems they’re trying to prevent.

“Applying evolutionary biology has tremendous potential because it takes into account how unwanted pests or pathogens may adapt rapidly to our interventions and how highly valued species, including humans …, are often very slow to adapt to changing environments through evolution,” says Peter Søgaard Jørgensen, a lead author from the Center for Macroecology, Evolution and Climate at the University of Copenhagen.

“Not considering such aspects may result in outcomes opposite of those desired, making the pests more resistant to our actions, humans more exposed to diseases, and vulnerable species less able to cope with new conditions.”

Prior research by Kinnison, professor of evolutionary applications, heightened awareness that evolution is a surprisingly dynamic process, often fastest on the shortest time frames — even in one or two generations — and is extensively shaped by human activities. Much of his research considers human evolutionary effects on fish and wildlife populations.

Prime examples affecting humans include pathogens and pests that quickly evolve resistance to antibiotics and pesticides.

“Uncontrolled evolution is often outpacing our best technology,” he says.

For instance, Kinnison and his collaborators note there are more than 11,000 documented cases of pesticide resistance in about 1,000 species of insects and weeds, and that plant pathogens jeopardize agricultural economies and food supplies worldwide.

And, the World Health Organization has warned that microbial resistance to antimicrobial drugs threatens achievements of modern medicine.

“But there is more to this than doom and gloom,” Kinnison says. “A major emphasis of our article is that there are some amazingly creative solutions being applied to manage evolutionary challenges and that these approaches can often be shared and adapted to meet new challenges.”

For example, farmers in the U.S. and Australia set aside pest-friendly refuges, or havens, to delay the evolution of insect resistance to costly chemical controls and genetically engineered crops that support the most production.

Researchers say these refuges have effectively suppressed resistance in the pink bollworm, an invasive pest of cotton.

The paper’s authors suggest refuge strategies may be adapted to broader applications, including preserving the economic value of fisheries and improving outcomes in cancer treatment.

Applied evolution is showing up in some surprising places. The U.S. Atlantic Salmon Recovery Program, and similar programs that use artificial breeding efforts to supplement dwindling wild populations, historically focused on avoiding losses of genetic variation.

These programs now also prioritize a need to avoid inadvertent adaptation of fish to captivity.

Research indicates salmon and other fish adapt rapidly to living in captivity and become dependent on humans, which Kinnison says negatively impacts their ability to survive in the wild.

Fisheries scientists thus seek to limit the number of generations that endangered salmon are bred in captivity and seek opportunities to incorporate new genetic contributions from wild fish.

To show the broad application of evolution to global challenges, the authors promote a simple framework for evolutionary management strategies based on adaptive “match” or “mismatch.”

Researchers say this framework reveals approaches that might otherwise be missed as evolutionary and is applicable to both fast- and slow-evolving species.

Scott P. Carroll, biologist at the University of California Davis and director of the Institute for Contemporary Evolution, says sharing ideas and strategies is particularly important to prevent the spread of new infectious diseases and antimicrobial resistance genes between natural, agricultural and human health systems.

The authors emphasize coordinating applied evolutionary principles across these traditionally isolated sectors and, in some cases, at international scales, will be necessary.

They highlight as an example the dual use of antibiotics in human health and food production. Livestock around the planet are given antimicrobial drugs to increase meat production. The astronomical number of livestock greatly increases the opportunity for evolution of resistant pathogens that might harm humans where animal and human antibiotics overlap in mechanism.

Those resistant pathogens can spread through global trade and, in some cases, exchange resistance genes with other strains, say the researchers.

Use of antibiotics in agricultural animals has been implicated in the origins of resistant Escherichia coli found in people afflicted with a potentially fatal whole-body inflammation.

“It’s sobering to think that farming practices in one part of the world might give rise to pathogens affecting human populations elsewhere,” Kinnison says.

“We need international policies that help mitigate such challenges.”

Jørgensen agrees that policy and coordination are critical.

“By using regulatory and redistribution tools, local communities and governments play a crucial role in ensuring that everybody gains from the benefits of using evolutionary biology to realize the long-term goals of sustainable development such as increasing food security, protecting biodiversity and improving human health and well-being,” he says.

Jørgensen will present the research team’s perspective during the Oct. 22-24 Sustainability Science Congress in Copenhagen. The study is online.

Contact: Beth Staples, 207.581.3777