It is widely believed that evolutionary dynamics of artificial self-replicators realized in cellular automata (CA) Key Words: cellular automata; self-replication; genetic evolution; diversity; adaptation S ince von Neumann's work on self-reproducing automata [1], artificial self-replication models based on cellular automata (CA) have formed one of the mainstreams in artificial life [2][3][4][5]. Recent developments indicate that simple CA with fixed rules can reproduce natural selection among different self-replicating structures [6,7], yet their evolutionary dynamics are considered quite limited in both diversity and adaptive behavior [8,9]. Contrary to these earlier observations, we show that genetic adaptation and diversification processes may occur in such simple CA. We investigate a system of evolving self-replicating loops, or evoloops [7], in which replication, variation and selection emerge solely from fixed local rules. Applying new tools for detailed genetic identification and genealogy tracing [10], we uncovered a genotypic permutation space that expands combinatorially with replicator size, within which loops exhibit significant diversity in macro-scale morphologies and mutational biases. Populations undergo nontrivial genetic adaptation, maximizing colony density while enhancing sustainability against other species. We also identified a set of nonmutable subsequences in the evoloop genetics, with which one can carry out genetic operations to alter fitness differentials and promote long-term evolutionary exploration. This effect is further manifested when populations are introduced to a hostile environment. These results demonstrate a unique example of genetic evolution that traverses multiple scales, hierarchically emerging from local interactions between elements much smaller than individual replicators.