Final answer:
The nearly neutral theory of molecular evolution includes the selection of traits encoded by neutral genetic changes, coevolution between amino acids and biosynthetic pathways, and selection for error minimization.
Step-by-step explanation:
The main components of the nearly neutral theory of molecular evolution include the selection of chemistries and traits encoded by random, neutral genetic changes. This theory suggests that the accumulation of these random changes has led to the diversity of species and their spread to different ecological niches. Additionally, the theory proposes that the genetic code evolved through coevolution between amino acids and biosynthetic pathways, as well as selection for error minimization to reduce the negative impact of mutational and translational errors.