marginally significantp = .085
When considering only the Dvov‐N populations, the ratio is marginally significant ( p = .085), suggesting a stronger effect of balancing selection at higher latitudes. 4 DISCUSSION 4.1 Historical process of species divergence This study suggests that the combination of geographic isolation and the effect of the latitudinal environmental gradient (temperature seasonality, in particular) in northwestern Mexico promoted the divergence between D. sonorense and D. vovidesii .