BIOCOMPLEXITY:
SPECIAL COMPETITION
Integrated Research to Understand and Model Complexity Among Biological, Physical, and Social Systems

Cognizant Program Officers:

• Complexity in the present day Antarctic dry valleys is governed by the interactions between paleoenvironmental conditions and short term fluctuations in modern physical and chemical processes. In addition, the most dynamic ecosystem activities occur over extremely small spatial scales. Research that integrates paleo and present day conditions and microscale and mesoscale phenomena is needed to better interpret and model the behavior of these extreme ecosystems.

• In order to understand land cover change processes, we need to better understand the impact of the constructed environment, human activities and social structures on ecosystem functions. For example, what is the affect of property rights allocations or cultural norms on the rate of deforestation in a given area? Research on these complex processes requires the collaborative efforts of scientists from a number of disciplines, including engineering and social, behavioral, biological, and computer sciences.

• As humans spread out of the tropics 100,000 or more years ago, they encountered a diversity of environments, necessitating adaptation to new diets, climates, infectious diseases and other stressors. Understanding the complex interplay of social institutions, behavior, and genetic change through time and space are key to unraveling the origins and extent of modern human diversity and our adaptations as a species.

• The environmental impact of industrial products over the long term is still not adequately understood. As new materials evolve and come into use, the impact of human endeavors on the environment will change. How can materials be designed to be resilient during use but biodegradable once discarded? What are the factors during production, use and disposal that must be considered in order to design materials with minimal environmental impact?

• Recent studies suggest that ecosystem processes are influenced by species diversity. However, the mechanisms are unclear. Research that tests mechanistic models relating species diversity of various groups of organisms to ecosystem productivity and response to disturbance may help unravel this puzzle. Such studies may help determine whether and how shifts in species diversity due to human activities broadly affect ecological functioning and are important to factor into economic models for sustainable ecosystem management.

• Biological invasions involve complex human and biological interactions at a variety of scales, from the very local and short term to the international and long term. Quantitative approaches that are required to understand biological invasions include: population models to analyze how characteristics of invader species and invaded communities affect each step of the invasion process, statistical meta-analysis of case studies to help identify general patterns in the characteristics of invaders, vectors, invaded communities and ecological impacts, and quantitative analyses of the impacts of human interests, including health, economics, and cultural values, on species invasions.

• Many geological processes, as well as those that operate on geological media and on materials used in the constructed environment and which were long thought to be strictly "inorganic" are now know to be directly or indirectly biologically controlled. Tools (e.g., molecular sequencing, laser confocal and atomic force microscopy, and environmental scanning electron microscopy) are now available to investigate the diverse, complex interactions between microbes and minerals. Some important themes to pursue in biocomplexity, geomicrobiology, and infrastructure stability include: formation and change through time of sediments and rock materials, microbial control of chemical composition of soils and the impact of microbial consortia on man-made structures.

• Marine organisms interact with the atmosphere by taking up or releasing trace gases that influence both the world's heat balance and the screening of harmful UV-B radiation. Nitrous oxide, dimethyl sulfide, methane, and methyl halides all have complex biological sources and sinks in marine systems. Each affects the heat balance of the earth, and some impact stratospheric ozone, which leads to increases in UV-B radiation, that in turn potentially can alter marine community structure, rates of photochemical transformation of dissolved organic matter, and thus carbon cycling in surface waters. These complex interactions and feedbacks, which are the hallmarks of trace gas dynamics between ocean and atmosphere, need to be investigated with regard to their biology.

• Single celled animals (protists) are key to understanding the evolution of more advanced organisms. Some species that reside in insect hind-guts contain within them organelles that are genetically related to mitochondria (the energy producing system in cells) and evolve hydrogen. There are other microorganisms that cluster around these organelles and use the hydrogen evolved for their own metabolism. The whole system is complex but modern genomic approaches make it possible to understand the dynamics of the system and its evolution.

• The nature and extent of interactivity between molecular scale phenomena and environmental factors and stressors is not well understood. For example, how are cellular processes such as self-replication and biosynthesis affected by changes in mineral composition, pollutants, or radiation levels? How has the mechanism of nutrient acquisition by organisms been shaped by competition from other organisms? Does competition for nutrients, or lack of it, result in discernable patterns in availability of particular nutrients?

• Biological networks (e.g., interacting genes, neurons, mycorrhizal fungi, plant roots), present an area where molecular, cellular and organismic biologists working with computer scientists (both software and hardware) can make progress in exploring very large-scale network problems. Thousands of interacting elements which determine emergent patterns can be represented as massive parameter spaces, and understood using computationally efficient methods.

• In many instances (locomotion, aggregation behavior, chemotaxis, etc.) sensors encode multimodal environmental stimuli (visual, mechanical and chemical) in nonlinear ways and process these through nonlinear filters. Responses to these stimuli modulate the sensitivity of the systems to stimuli. Moreover, memory and plasticity further confound simple linear analyses. Information is processed very fast, in adaptive and flexible ways, spanning a wide range of spatial and temporal scales. Biologists, in collaboration with computer scientists, need to develop adaptive and robust models and efficient algorithms for representing and understanding biological systems.

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