Table 2.

Mapping between biological and information networks.

	circulatory system	brain	chips	Internet
components	capillaries/mitochondria	neurons	transistors	hosts
links	blood vessels	dendrites, axons	wires	fibre
what flows	blood (oxygen, glucose)	action potentials	charge carriers (electrons)	packets (information)
the last mile	capillary to mitochondria	synapse	isochronic region (for clock trees)	local area network
network properties	hierarchical, fractal branching, space-filling, three dimensions	neural connectivity, space-filling, three dimensions	hierarchical, space-filling, 2.5 dimensions	hierarchical, space-filling, two dimensions
what is optimized	maximize metabolic rate, minimize transport costs and times	maximize information processing, minimize metabolic demand	maximize processing minimize power	maximize throughput minimize latency
fundamental principles	conservation of energy and matter	conservation of energy and matter	Kirchhoff's laws (conservation of current and voltage)	telegrapher's equation
driving process	natural selection	natural selection	engineering economics	engineering economics self-organization