What primary selective pressures led to the significant genetic divergence observed in laboratory zebrafish strains?

Founder effects combined with selection for laboratory traits and relaxed selection on wild survival traits

The genetic gap separating laboratory zebrafish from their wild progenitors is largely attributable to the intense selection pressures imposed by laboratory maintenance. The founding stocks were derived from a limited sample of wild fish, resulting in severe founder effects which immediately reduced initial genetic diversity. Subsequently, laboratory life introduced unique selective forces: intentional selection for traits beneficial in the lab (which may or may not align with wild advantages) and, conversely, relaxed selection on traits that are critical only in the wild, such as the necessity for predator avoidance mechanisms. This environmental shift created a new evolutionary trajectory distinct from that in the native Ganges-Brahmaputra basin populations.