The biosphere that exists today is complex and heterogeneous, not only with recent, history-dependent order, but with diverse ancient forms of order that all appear to be fundamental to the nature of the living state. Rather than propose an origin of life that projects away this diversity by seeking the emergence of a single kind of entity or process, we ask what essential functions and contributions to persistence of the biosphere come from forms or order at different levels. Fundamental constraints on the possible ways to assemble living systems are captured by grouping organism phenotypes according to their chemical energy sources for electron transfers (donors or acceptors), and according to whether they are metabolically self-sufficient or can only live using resources extracted from larger ecosystems. The same bioenergetic distinctions exist for ecosystems as for organisms, but as ecosystem boundaries can often be constructed to be metabolically closed, ecosystems are in a sense simpler and more universal than organisms. The universal aspects of metabolism are ecosystem properties, and core biosynthesis powered by electron donors is more fundamental, universal, and ancient than degradative pathways that contribute much of ecological complexity. Whether the emergence of our biosphere was surprising or inevitable is not well posed as a single question; some low-level features of biochemistry seem to have inherited nearly the inevitability of geochemistry, while the character of any particular species is an epitome of chance. Key patterns, many of chemical origin, are nonetheless recapitulated across the spectrum from necessity to chance, and in some cases we can make explicit arguments that constraint flowed upward in scale from metabolic foundations because chemistry dictates paths of least resistance for evolution across a wide range of scales.