Evolutionary history of Chinese cavefishes parallels paleogeoclimatic and river capture processes

To elucidate their evolutionary origins and diversification history, we analyzed 183 cave species and their close relatives from ten clades. Our findings reveal that freshwater fishes start colonized caves ~44 million years ago (Ma).

The primary driver of speciation was in situ diversification, which began around 43.8 Ma, increased sharply by ~25 Ma, and showed peaks at ~10 Ma and 2.4 Ma, with a valley at ~3.3 Ma. Distinct hydrological basins exhibited divergent diversification patterns. Dispersal from the Pearl River to the Yangtze River and vice versa began around 23.8 Ma and 12.6 Ma, accelerated at ~13 Ma and 8.2 Ma, and peaked at 16 Ma, 2 Ma, and 5 Ma, respectively.