Many biological systems are composed of unreliable and noisy components self-organizing efficiently into systems that can solve complex problems. One such example is the true slime mold {\em Physarum polycephalum} which is an amoeba-like organism that seeks food sources and efficiently distributes nutrients throughout the cell body. The cell body can grow to be centimeters in size. The distribution of nutrients is accomplished by a self-assembled resource distribution network of small tubes of varying diameter which can evolve with changing environmental conditions without any global control. In this paper, we use a phenomenological model for tube evolution in slime mold and map it to a path formation protocol for wireless sensor networks. By selecting certain evolution parameters in the protocol, the network will evolve toward single paths connecting data sources to a data sink. In other parameter regimes, the protocol will evolve toward multiple redundant paths. We present detailed analysis of a small model network. A thorough understanding of a simple network leads to design insights into appropriate parameter selection, and also validates the design via large-scale simulation of realistic wireless sensor networks using the QualNet network simulator.