Fluid flows can induce long-ranged interactions and propagate information on large scales. Especially during the development of an organism, coordination on large scales in short time is essential. We aim to discover the principal mechanisms of how fluid flows induce, transmit and respond to biological signals and thus orchestrate the morphing of an organism.

The role of fluid flows in patterning and morphing is particularly prominent during the growth and adaptation of transport networks like vascular networks. Here, the network-forming slime mold Physarum polycephalum emerged as a new model to study the complex dynamics of transport networks. Investigating the pivotal role of fluid flows in this live transport network we find that flows are patterned in a peristaltic wave across the network thereby optimizing transport. In fact, flows are hijacked by signals to propagate throughout the network promoting their own transport by invoking a propagating front of increased flow. These simple non-linear dynamics are sufficient to explain surprisingly complex dynamics of the organism like finding the shortest path through a maze.

Turning to vascular networks of plants and animals we investigate the requirements on the network to provide uniform supply of metabolites to surrounding tissues. Solving for metabolite absorption dynamics we identify the fluid inflow rate as the most important factor. Theoretically uncovered rescue responses to counteract sub-optimal inflow match observations of network adaptation in plant and animal vasculature.