Many enthusiasts of theistic evolution willingly accept Aquinas’s distinction between primary and secondary causes, to describe theologically “the mechanics” of evolutionary transformism. However, their description of the character of secondary causes in relation to God’s creative action oftentimes lacks precision. To some extent, the situation within the Thomistic camp is similar when it comes to specifying the exact nature of secondary and instrumental causes at work in evolution. Is it right to ascribe all causation in evolution to creatures—acting as secondary and instrumental causes? Is there any space for a more direct divine action in evolutionary transitions? This article offers a new model of explaining the complexity of the causal nexus in the origin of new biological species, including the human species, analyzed in reference to both the immanent and transcendent orders of causation.