Final answer:
Phylogenetic trees depict evolutionary divergence rather than simple similarity, with branch lengths indicating sequence, not time. Evolution in trees can continue in multiple directions, and unrelated species may sometimes appear similar due to convergent evolution.
Step-by-step explanation:
The statement 'reflects evolutionary sequence of branching events, not just degree of similarity among groups' means that phylogenetic trees are designed to represent the evolutionary sequence in which species have diverged from common ancestors over time, rather than merely showing how similar different species may appear to be. A branch's length on a phylogenetic tree does not necessarily correspond to the amount of time that has passed, but instead, it indicates the evolutionary order of divergence. Phylogenetic trees also do not grow in only one direction after a new branch develops, meaning that the evolution of new traits in one branch does not halt the evolution of others. Additionally, sometimes organisms that are not closely related evolve similarly under comparable conditions, a phenomenon known as convergent evolution, potentially leading to them resembling each other more than they do their actual close relatives.