Tuesday, March 9, 2010
Ecology and industry: bridging the gap between economics and the environment
This is the premise of a paper by Paul Armsworth and 15 other authors on the ecological research needs of business, appearing in the Journal of Applied Ecology (for an interview with Paul, by yours truly, please go to the podcast, and I should point out that I am an Editor with this journal). The authors include academics, NGOs and industrial representatives, and they've come together to analyze patterns of cooperation and to discuss ways forward.
They reviewed papers appearing in the top applied ecology journals and grant proposals to the National Environmental Research Council (NERC) in the UK to measure the degree and type of interaction between ecologists and different industries. Ten to 15 percent of publications in applied journals showed some business involvement -mostly from the traditional biological resource industries (farming, fishing and forestry). Further, 35% of NERC proposals included some business engagement, but only 1% had direct business interaction.
Further, the authors reported on a workshop where ecologists and business representatives discussed a number of topics. This included how to minimize negative biodiversity impacts and for industries, such as mining, to consider ecosystem function, and how to develop new ecologically-based economic opportunities, such as insurers managing environmental risk. While there were some challenges identified (such as differing time frames of business needs versus scientific research), the authors note the positive atmosphere and the spirit of collaboration.
The research in this paper should be emulated elsewhere. A better understanding of business needs and desires can only inform and offer opportunities for applied ecological research. Top-down governmental regulation can only take conservation and ecosystem management so far and those who are directly involved in altering and managing ecosystems must articulate goals and desires in order to successfully apply ecological principles to biodiversity protection in an economic landscape.
Armsworth, P., Armsworth, A., Compton, N., Cottle, P., Davies, I., Emmett, B., Fandrich, V., Foote, M., Gaston, K., Gardiner, P., Hess, T., Hopkins, J., Horsley, N., Leaver, N., Maynard, T., & Shannon, D. (2010). The ecological research needs of business Journal of Applied Ecology, 47 (2), 235-243 DOI: 10.1111/j.1365-2664.2010.01792.x
Friday, March 5, 2010
Competitive coexistence, it's all about individuals.
In order for two species to coexist, intraspecific competition must be stronger than interspecific -so sayeth classic models of competition. While people have consistently looked for niche differences that reduce interspecific competition, no one has really assessed the strength of intraspecific competition. Until now that is. In a recent paper in Science, Jim Clark examines intra- vs interspecific interactions from data following individual tree performances, across multiple species, for up to 18 years. This data set included annual growth and reproduction, resulting in 226,000 observations across 22,000 trees in 33 species!
His question was actually quite simple -what is the strength of intraspecific interactions relative to interspecific ones? There are two alternatives. First, that intraspecific competition is higher, meaning that among species differences only need to be small for coexistence to occur; or secondly, that intraspecific competition is lower, requiring greater species niche differences for coexistence. To answer this he looked at correlations in growth and fecundity between individuals either belonging to the same or different species, living in proximity to one another. He took a strong positive correlation as evidence for strong competition and a negative or weak correlation as evidence for resource or temporal niche partitioning. What he found was that individuals within species were much more likely to show correlated responses to fluctuating environments, than individuals among species.
This paper represents persuasive evidence that within-species competition is generally extremely high, meaning that to satisfy the inequality leading to coexistence: intra > inter, subtle niche differences can be sufficient. These findings should spur a new era of theoretical predictions and empirical tests as our collective journey to understanding coexistence continues.
Clark, J. (2010). Individuals and the Variation Needed for High Species Diversity in Forest Trees Science, 327 (5969), 1129-1132 DOI: 10.1126/science.1183506
Tuesday, March 2, 2010
Check out the carnival of evolution and be sure to vote for your favorite blogs
Also, Research Blogging has announced finalists for various blogs awards. If you are eligible, please vote, there are a lot of great blogs vying for these awards. Also, The EEB and Flow is among the finalists for best biology blog. And to the people we nominated us, thanks again for nominating our blog.
Saturday, February 27, 2010
New Tool Reveals Where Ticks Eat Breakfast
You have a much greater chance of getting sick from a tick bite today than you did 30 years ago. But a new tool might allow researchers to better understand why more ticks are making people sick.
“If you’re a health inspector and a bunch of people get food poisoning, the first thing you’d want to know is where they ate last. If you’re a disease ecologist and a bunch of ticks have a pathogen, the first thing you’d want to know is where the ticks ate last,” said Brian Allan, a post-doctoral researcher at the Tyson Research Station in St. Louis.
Allan led a team of researchers in developing a novel technology that probes the genetic contents of ticks’ gut. The tool can determine which wildlife species provided the tick’s last meal and which pathogens came along with that meal.
In the first study to use the new technology, Allan and his colleagues focused on several rapidly emerging diseases transmitted by the lone star tick. These include two pathogens responsible for a potentially fatal bacterial infection known as ehrlichiosis [ur-lick-ee-oh-sis]. In Missouri, over 200 cases of ehrlichiosis were documented last year.
Allan et al.'s study showed that about 80 percent of pathogen-positive ticks had fed on white-tailed deer. They also found that squirrels and rabbits were capable of infecting ticks at a higher rate than deer. However, since the lone star tick feeds on squirrels and rabbits less frequently, they account for a smaller percentage of infection.
Allan and his colleagues hope that the technique will shed light on theoretical questions in the field of ecology. They are especially interested in testing whether biodiversity is good for your health, a hypothesis known as “the dilution effect.”
Allan, B. F., L. S. Goessling, G. A. Storch, and R. E. Thach. 2010. Blood meal analysis to identify reservoir hosts for Amblyomma americanum ticks. Emerging Infectious Diseases 16: 433-440. DOI: 10.3201/eid1603.090911
Monday, February 22, 2010
How can evolution inform conservation decisions?
The conservation of biological diversity is a major imperative for biologists. International agreements such as the Convention on Biological Diversity and intergovernmental exercises, such as the Millennium Ecosystem Assessment, call upon scientists to provide evidence on the current state of biological diversity and to evaluate solutions for reducing diversity and ecosystem function loss. Critical to these efforts have been the work of ecologists, conservation biologists and ecological economists. However, seemingly missing from the conversation about the state of biodiversity knowledge has been evolutionary biologists. Are they primarily concerned with describing historical processes and mechanisms of biological change, or do they have substantive knowledge and ideas that should be viewed as a critical component of any scheme to conserve biological diversity?
In a recent paper in Evolution, Hendry and a number of coauthors convincingly make the case that evolutionary biology is a necessary component for conservation. Evolution offer four key insights that should inform conservation and policy decisions. First, they point out that evolutionary biologists are in the business of discovering and documenting biodiversity. They are the primary drivers behind long-term, sustained biological collections, because they need to know what exists in order to better understand evolutionary history. With millions of species awaiting scientific discovery, their efforts are critical to measuring biodiversity. But not only are they discovering new species and enumerating them, they are uncovering their evolutionary relationships, which gives conservationists better information about which species to prioritize. What Vane-Wright famously called 'the agony of choice', with limited resources, we need to prioritize some species over others, and their evolutionary uniqueness ought to be a factor. More than this, evolutionary biologists have developed pragmatic tools for inventorying and sharing data on biodiversity at all levels, from genes to species, which is available for prioritization.
The second key insight is that by understanding the causes of diversification, we can better understand and predict diversity responses to environmental and climatic change. By understanding how key functional traits evolve, we can develop predictions about which species or groups of species can tolerate certain perturbations. Further, research into how and why certain evolutionary groups faced extinction can help us respond to the current extinction crisis. For example, the evolutionary correspondence between coevolved mutualists, such as plants and pollinators, can be used to assess the potential for cascading extinctions. These types of analyses can help identify those groups of related species, or those possessing some trait, which make species more susceptible to extinction.
Thirdly, evolution allows for an understanding of the potential responses to human disturbance. Evolutionary change is a critical part of ecological dynamics, and as environment change can result in reduced fitness, smaller population sizes and extinction, evolution offers an adaptive response to these negative impacts. Knowing when and how populations can evolve is crucial. Evolutionary change is a product of genetic variation, immigration, population size and stochasticity, and if the ability to evolve to environmental change is key for persistence, then these evolutionary processes are also key.
Finally, evolutionary patterns and processes have important implications for ecosystem services and economic and human well-being. Both genetic and evolutionary diversity of plant communities has been shown to affect arthropod diversity, primary productivity (including work by me) and nutrient dynamics. Thus understanding how changes in diversity affect ecosystem processes should consider evolutionary processes. Further, exotic species are often cited as one of the major threats to biodiversity, and evolutionary change in exotics has been shown to increase exotic impacts on native species.
All together, these key reasons why evolution matters for conservation, mean that developing sound management plans requires considering evolution patterns and processes. We can use evolution to our benefit only if we understand how evolution shapes current dynamics. The challenge to evolutionary biologists is the same as it was for ecologists perhaps 15 to 20 years ago, to present their understanding and conservation ideas to a broader audience and to engage policy makers. To this end, the authors highlight some recent advances in incorporating evolutionary views into existing biodiversity and conservation programmes –most notably into DIVERSITAS.
Just like ecological processes and dynamics cannot be fully understood without appreciating evolution ancestry or dynamics, developing an extensive, expansive conservation strategies must take into account evolution. I hope that this paper signals a new era of a synthesis between ecology and evolution, which produces precise, viable conservation strategies.
Hendry, A., Lohmann, L., Conti, E., Cracraft, J., Crandall, K., Faith, D., Häuser, C., Joly, C., Kogure, K., Larigauderie, A., Magallón, S., Moritz, C., Tillier, S., Zardoya, R., Prieur-Richard, A., Walther, B., Yahara, T., & Donoghue, M. (2010). EVOLUTIONARY BIOLOGY IN BIODIVERSITY SCIENCE, CONSERVATION, AND POLICY: A CALL TO ACTION Evolution DOI: 10.1111/j.1558-5646.2010.00947.x
Wednesday, February 10, 2010
Research blogging awards; and thanks
Monday, February 8, 2010
Predator-human conflict: the emergence of a primordial fear?
Such is the case for three recent animal attacks in Canada. In late October, 2009 in Nova Scotia, a raising 19-year old folk singer was killed by a couple of coyotes while hiking. It is difficult to find meaning in such a horrendous death, but the narrative, told by reporters, was essentially to rest assured that one of the coyotes had been killed and the other was being tracked and would be destroyed. There were two cougar attacks in early January, 2010 in British Columbia, that basically ended with the same reassurance. In the first, a boy was attacked and his pet golden retriever courageously saved his life. A police officer arrived a shot the cougar which was mauling the dog -an obviously legitimate response, and the news story again reassures us that the animal was destroyed. And don't worry the hero dog survived. In the second cougar attack, another boy was attacked, and this time his mother saved his life. But again the story narrative ended by reassuring us that the guilty cougar, and another cat for good measure, were destroyed the next day.
After reading these stories, I asked myself two things. Why is our response to destroy predators that attack? And why do we need to be reassured that this has happened? In defence of the predators, they are just doing what their instincts tell them to do, and most often their only mistake is that they selected their prey poorly. But the reality is that there are only 2-4 cougar attacks per year and only 18 fatalities over the past 100 years. Why do we fear such a low probability event? In contrast, automobile accidents are the leading cause of death in children under 12 in North America. Thousands of people die, and millions injured in car accidents every year in North America. Recently, in Toronto, were I live, 10 pedestrians were killed in 10 days, yet my heart doesn't race when I cross a street. If our fears and responses to human injury and death reflected the actual major risks, we would invoke restrictive rules regarding automobile use.
We believe that we can live with nature in our backyard. But when that close contact results in an animal attack, human fear seems to dictate an irrational response. Do we really expect predators to obey our rules? Can we punish them enough to effectively tame them? We cannot, and I hope that our approaches to dealing with human-animal conflict can better deal with animal attacks, in a way that does not subjugate large predators to whims of our fears.
Wednesday, February 3, 2010
The evolution of a symbiont
In a recent paper, Marchetti and colleagues answer part of the question. They experimentally manipulate a pathogenic bacteria and observe it turning into a symbiont. They transferred a plasmid from the symbiotic nitrogen fixing Cupriavidus taiwanensis into Ralstonia solanacearum and infected Mimosa roots with it. Plasmid transfer among distinct bacteria species is common and referred to horizontal genetic transfer (as opposed to vertical, which is the transfer to daughter cells). The presence of the plasmid caused R. solanacearum to quickly evolve into a root-nodulating symbiont. Two regulatory genes lost function, and this caused R. solanacearum to form nodules and to impregnate Mimosa root cells.
This extremely novel experiment reveals how horizontal gene transfer can supply the impetus for rapid evolution from being a pathogen to a symbiont. More importantly it reveals that sometimes just a few steps are required for this transition and how distantly-related bacterial species can acquire symbiotic behaviors.
Marchetti, M., Capela, D., Glew, M., Cruveiller, S., Chane-Woon-Ming, B., Gris, C., Timmers, T., Poinsot, V., Gilbert, L., Heeb, P., Médigue, C., Batut, J., & Masson-Boivin, C. (2010). Experimental Evolution of a Plant Pathogen into a Legume Symbiont PLoS Biology, 8 (1) DOI: 10.1371/journal.pbio.1000280
Wednesday, January 27, 2010
To intervene or not to intervene: this is a real question
doi: 10.1890/090089
http://www.esajournals.org/doi/abs/10.1890/090089
Tuesday, January 19, 2010
Timing is everything: global warming and the timing of species interactions
In an 'Idea and Perspective' paper in Ecology Letters, Louie Yang and Volker Rudolf set out a new framework to examine the effects of phenological shifts on species interactions. They argue that one cannot understand or predict the fitness consequences of a phenology shift without knowing how interacting species' phenologies are also influenced by environmental changes. The consequences of phenological shifts are changes in fitness, and the question is: how would one go about assessing the fitness effects of phenological changes on interactions? This is where this paper really hits its stride. Yang and Rudolf set out a new conceptual framework for studying the fitness consequences of phenological shifts. They make the case that an experimental approach is required to test the three likely scenarios. The first is that there are no changes in phenology -that is, measuring the fitness levels of the two interacting species under stable conditions. Second, you induce an experimental shift in the timing of one of the species. For example, in a plant-herbivore interaction, germinate the plant earlier and when the herbivore normally has access to the plant, the plant will be older. What are the fitness changes associated with this shift? Finally, you can shift the timing of the other species relative to the first. In our example, the herbivore has access to younger plants and again are there fitness consequences?
Yang and Rudolf call the full combination of possible fitness effects, across a number of timing mismatches, 'the ontogeny-phenology landscape'. By mapping fitness changes across this ontogeny-phenology landscape, researchers can offer better predictions, on top of just changes in range size or habitat use, about the possible affects of climate change. The obvious question, and Yang and Rudolf acknowledge this, is how to extend two-species ontogeny-phenology to multi-species communities. Of course, extending two-species interactions to communities is a question that plagues most of community ecology, but I think the solution is that researchers who know their systems often have intuition about the major players, and thus those species where phenology shifts should have disproportionate effects on other species. Such species could be the place to start. Another strategy would be a food web type approach, where species are lumped into broader trophic groups and we ask how shifts in certain trophic groups affect other groups.
Regardless of how to extend this framework to multispecies assemblages, I see this paper as likely to be very influential. It gives researches a new focus and framework, where specific predictions about climate change can be made.
Yang, L., & Rudolf, V. (2010). Phenology, ontogeny and the effects of climate change on the timing of species interactions Ecology Letters, 13 (1), 1-10 DOI: 10.1111/j.1461-0248.2009.01402.x