|A depiction of autocatalytic closure, according to Irish artificial life researcher James Decreane, where in A: simple collectively autocatalytic reaction network, where the species x1 catalyzes the production of x2. Similarly the production of x3 and x1 can be catalyzed by x2 and x3 respectively, forming/closing the autocatalytic loop; in B: A three element hypercycle, in contrast to collectively autocatalytic reaction networks, individual molecular species are capable of self-production in hypercycles. |
The model is a variant of the 1920s autocatalysis theory, and was first proposed by American Stuart Kauffman in his 1993 The Origins of Order and the expanded on in a number of books to follow as a pervading principle germane to life. 
● Perpetual motion of the living kind
1. Thims, Libb. (2007). Human Chemistry (Volume One) (pg. 133). Morrisville, NC: LuLu.
2. Kaufmann, Stuart. (1993). The Origins of Order: Self-Organization and Selection in Evolution (catalytic closure, 26+ pgs). Oxford University Press.
3. Decraene, James (2009) Autocatalytic Closure and the Evolution of Cellular Information Processing Networks (abs). PhD thesis, Dublin City University.
● Autocatalytic set – Wikipedia.