  Life has most likely originated as a consequence of processes taking place in
non-equilibrium conditions (\textit{e.g.} in the proximity of deep-sea thermal
vents) selecting states of matter that would have been otherwise unfavorable at
equilibrium. Here we present a simple chemical network in which the selection
of states is driven by the thermodynamic necessity of dissipating heat as
rapidly as possible in the presence of a thermal gradient: states participating
to faster reactions contribute the most to the dissipation rate, and are the
most populated ones in non-equilibrium steady-state conditions. Building upon
these results, we show that, as the complexity of the chemical network
increases, the \textit{velocity} of the reaction path leading to a given state
determines its selection, giving rise to non-trivial localization phenomena in
state space. A byproduct of our studies is that, in the presence of a
temperature gradient, thermophoresis-like behavior inevitably appears depending
on the transport properties of each individual state, thus hinting at a
possible microscopic explanation of this intriguing yet still not fully
understood phenomenon.
