CONTEXT-DEPENDENT MACROSCOPIC PATTERNS IN GROWING AND INTERACTING MYCELIAL NETWORKS

Fungal mycelia epitomize, at the cellular level of organization, the g rowth and pattern-generating properties of a wide variety of indetermi nate (indefinitely expandable) living systems. Some of the more import ant of these properties arise from the capacity of an initially dendri tic system of protoplasm filled, apically extending hyphal tubes to an astomose. This integrational process partly restores tile symmetry los t during the proliferation of hyphal branches from a germinating spore and so increases the scope for communication and transfer of resource s across the system. Growth and pattern generation then depend critica lly on processes that affect the degree to which resistances to energy transfer within the system are sustained, bypassed or broken down. We use a system of reaction-diffusion equations augmented with appropria te initial data to model the processes of expansion and pattern format ion within growing mycelia. Such an approach is a test of the feasibil ity of the hypothesis that radical, adaptive shifts in mycelial patter n can be explained by purely contextual, rather than genetic, changes. Thus we demonstrate that phenotype does not necessarily equate solely to genotype-environment inter actions, but may include the physical r ole in self-organization played by the boundary between the two.