Figure 4. Molecular dating of the East Asian groups of cyprinids.

The fossil-based constraints are indicated with black dots. Branch lengths are proportional to divergence times (in million of years). The East Asian cyprinids originated mostly in Piocene but some occurred more recently. “S” indicates possible weakening of the Indian and East Asian summer monsoons and continued strengthening of the East Asian winter monsoon, an important time of climatic change and habitat modification that existed during the evolution of the lacustrine species.