The phrase "acme of variation" implies the highest point or pinnacle of diversity. Synonyms for this term include "culmination of distinctiveness," "zenith of diversity," "height of heterogeneity," and "apex of multiplicity." Other similar phrases to describe the peak of variation might include "summit of divergence," "crest of differentiation," "peak of contrast," or "pinpoint of disparity." Whatever phrase is chosen, the meaning is clear: the phrase refers to the ultimate degree or peak of variation, the point at which differences are most pronounced and diverse. It is a powerful and evocative term that captures the essence of the full range of differences within a system or group.