Chemical Fueling Enables Molecular Complexification of Self?Replicators**

Unravelling how the complexity of living systems can (have) emerge(d) from simple chemical reactions is one grand challenges in contemporary science. Evolving self-replicating molecules may hold key to this question. Here we show that, when a system replicators subjected regime where replication competes with replicator destruction, and fast give way more complex slower ones. The structurally was found be functionally proficient catalysis model reaction. These results that fueling maintain out equilibrium, populating are otherwise not readily accessible. Such complexification represents an important requirement for achieving open-ended evolution as it should allow improved ultimately also new functions emerge.