This approach, however, of Aeolians to Ionians is ambiguous and accidental, and historical indications go far to show that their distinction was all but primitive; that Dorism developed independently from an Aeolism with which Ionism was already in marked contrast, at some point of earlier departure, rather than that Ionism and Dorism together were collateral shoots from an original main Aeolic stem.
Source: wiktionary