This chapter reconstructs how Nalca, a Mek language of the Trans-New Guinea phylum, has acquired gender markers and describes the non-canonical properties of this highly unusual gender system. Gender in Nalca is mainly assigned by two different defaults, phonological assignment is holistic, there is a gender switch depending on the syntax of the noun phrase, controller and target are adjacent, and gender has the function of case marker hosts. Gender in Nalca is only weakly entrenched in the lexicon and predominantly phrasal. It is argued that canonical gender is an attractor (a complex, diachronically stable structure with heterogeneous origins). A model of the gender attractor based on the notion of information transfer chain is developed. The rise of Nalca gender is an instance of system emergence where several diachronic processes, such as grammaticalization, reanalysis, and analogy, interact. Chains of rapid diachronic change are triggered by anomalies that entail other anomalies.