I am somewhat loathe to post this, as it is a cop-out, but it may be useful to some.
A working understanding of the implications of variation of the degrees of freedom in complex adaptive systems is broadly helpful in life (both one's own, and biological life as a phenomenon). For seminal or survey work illustrating this, compare:
In this vein, it's also advisable to have a grasp of the equipartition theorem (
http://vallance.chem.ox.ac.uk/pdfs/Equipartition.pdf), and how quantization affects it, and the role of the ergodic hypothesis in deriving basic results of thermodynamics (
http://www.sbfisica.org.br/rbef/pdf/060601.pdf).
The most predictive models of large ensemble systems are either a direct consequence of, or deeply effected by, these principles. I may expand on the connections, and survey how I see them relating to this thread in future if time permits. At the moment it does not, but I provide the references for those motivated to investigate.