Structural dependencies have long been explored in the context of software quality. More recently, software evolution researchers have investigated logical dependencies between artifacts to assess failure-proneness, detect design issues, infer code decay, and predict likely changes. However, the interplay between these two kinds of dependencies is still obscure. By mining 150 thousand commits from the Apache Software Foundation repository and employing object-oriented metrics reference values, we concluded that 91% of all established logical dependencies involve non-structurally related artifacts. Furthermore, we found some evidence that structural dependencies do not lead to logical dependencies in most situations. These results suggest that dependency management methods and tools should rely on both kinds of dependencies, since they represent different dimensions of software evolvability.