For most of its history, ecology has been dominated by small-scale field work and studies of specific ecosystems. Now, some ecologists are calling upon their peers to think bigger, and to bring the field into the era of Big Science. And it does not come much bigger than computational ecologist Drew Purves’s suggestion of modeling all life on Earth. Purves, a researcher at Microsoft’s computer science research center in Cambridge, United Kingdom, is building a prototype that simulates entire ecosystems across the planet. Known as the Madingley model, Purves’s simulation captures the life, growth, migration, interactions, and death of individual creatures, and the flow of energy and nutrients between them. Rather than modeling specific species, the Madingley model places them into broad bins, like carnivore or herbivore, diurnal or nocturnal, birds or mammals. And rather than simulating every individual—an impossibly large task for modern computing—the model uses “cohorts” to represent similar clusters of individuals, such as fish shoals. It sound ambitious, perhaps unrealistically so. As Bob Paine, a marine biologist from the University of Washington, said, “it’s mission impossible”. Global models hinge on the interactions between species, Paine argued, and discovering those interactions depends on the small-scale, muddy-boots ecology he has long championed. In the 1960s, Paine coined the concept of a keystone species—one that has a disproportionate influence on its ecosystem—after throwing starfish off a beach and showing that mussels would take over. These interactions are unpredictable, and discovering them “requires intense biological studies, often of single species”, said Paine. Paine also rails against the approach of aggregating species into “gross, clumsy units”. Not all birds or carnivores or fliers behave in the same way, he said. Some species of starfish act as keystones but not others, and even those will influence their communities to different degrees depending on what part of the world they are in. Conversely, species from disparate categories can fulfil the same roles. “You can have a big crab in the Pacific that occupies the same niche as a British earthworm”, Paine said. “That’s invisible in the [Madingley] model and takes a lot of work to discover.” But Purves argues that we have enough data to get started, such as ratios of predators to prey in specific niches, and the metabolic rates and life-spans of many species. “The ecological community has a tendency to assume that it isn’t possible and we want to challenge that”, he said. “You don’t know until you try.” He points to the climate change community as an example of how big models can change the way research is done. “There was a lot of skepticism about whether there’d be a global climate model just until the first one was built”, he said. Now, such models are the status quo in climate science and regularly feed into the work of the Intergovernmental Panel on Climate Change.
Posted on: Fri, 21 Jun 2013 20:57:18 +0000
Trending Topics
Recently Viewed Topics
© 2015