Jim Rutt defines the term 'custodial species' as a conceptual framework wherein a given species, specifically humanity, assumes the role of a caretaker for the biosphere. In Rutt's view, this extends beyond merely avoiding harm to proactively managing and nurturing ecological systems to sustain and enhance the quality of life for all species. This custodial responsibility arises from both ethical imperatives and practical necessities, acknowledging the intertwined fate of human civilization with the broader ecosystem. It implies an evolved stewardship where technological, cultural, and ethical advancements are leveraged to preserve biodiversity, mitigate environmental degradation, and ensure a resilient and thriving planetary habitat. Rutt’s perspective on custodial species encapsulates a comprehensive guardianship approach, reflecting a deep-seated recognition of humanity's potential to both destructively impact and benevolently sustain the Earth’s intricate life-support systems.

See also: evolution, emergence, proto b, crypto, edge of chaos