The absolute simplicity of the three plus–minus combinations for two-species dynamics, explored in the previous chapter, is converted by natural selection into physical forms of splendid complexity—unexpected and subtle, spectacular and sublime, stunning and beautiful.
From our human perspective, some details appear to embody timeless altruism and kindness, others unbounded horror and cruelty. But nature seems to implement material possibilities without regard to human values, and we are left merely to observe and wonder, and strive to understand.
At this point, to gain perspective before proceeding further, it is well to examine at least a tiny subset of ecological reality. The range of examples of multi-species interactions looks endless, and even within individual organisms are interactions among multiple species.