Variation in frequencies of the ND4 substitution among rivers was negatively correlated to latitude (parameter estimate = −0.12, SE = 0.05, P = 0.02) and summer temperature (estimate = −0.027, SE = 0.13, P = 0.057), and positively correlated to longitude (estimate = 0.04, SE = 0.01, P = 0.006) using a quasibinomial link to correct for overdispersion (residual deviance = 60.580 on 25 degrees of freedom).
Source: wiktionary