CABDyN Project People
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Dan Bebber Research Fellow in Biology St. Peter's College, University of Oxford and Head of Climate Change Research Earthwatch Institute |
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Dan Bebber works with Mark Fricker on the structure and dynamics of fungal networks. The fungal mycelium is a transport network that competes in a complex and changing environment. The architecture of the network continuously adapts to local nutritional or environmental cues, damage or predation, through growth, branching, fusion and regression. Unlike many other biological networks (neural nets, metabolic interactions), which are part of an organism, the fungal network is the organism. There are an infinite number of ways in which fungi could build networks, that would vary in properties such as the amount of material required to build them, their resilience to different modes of attack, and their capacity to transport materials. Mycelial structure varies among fungal species, showing that Darwinian evolution has found many solutions to the problem of building networks. This makes fungi particularly interesting models for the analysis of what makes a 'good' network, and how the different structures can be appropriate for different environments. Two complementary approaches are used to investigate the properties of fungal networks. First, radiolabelling of non-metabolized nutrient analogues allows in-vivo imaging of transport through mycelium in real time. This has shown that transport through some, though not all, species has a pulsatile component. Although the mechanism behind pulsing remains unknown, imaging tentatively suggests that pulsing may result from periodic extension and recycling of hyphae as the fungus grows. Comparing the morphological structure of the mycelium with transport images reveals considerable control of flow to a subset of possible paths, with possible functional implications. Second, theoretical analyses of network morphology have shown that the organization of link strengths in the fungal network engenders greater transport efficiency and resilience when compared with null models. As the fungus grows, certain links are lost while others are strengthened, so increasing transport capacity to the residual network. Links to newly-found resources are strengthened the most. Work continues on comparisons among fungal species, and responses of the network to resource acquisition and disturbance. Bebber DP, Darrah PR, Hynes J, Boddy L & Fricker MD 2007. Biological solutions to transport network design. Proc. R. Soc. B in press. doi: 10.1098/rspb.2007.0459 Contact details: | |