Table 4.

Results of stepwise regression analysis. (Effective population size (N_e), residency or 1−m (ρ) and genetic distance (F_ST/1−F_ST) for each species, showing variables as X1, X2, etc. with parameter estimates (s.e.), R² contribution and p-values for each explanatory variable.)

Y	species	X1	X2	X3	X4	X5	R2	p-value
Ne	T. elegans	ELEG					0.565	<0.0001
	62.73 (12.62)
	<0.0001; 0.565
T. sirtalis	SIRT	ELEV	NN-ELEV			0.814	<0.0001
	19.92 (2.43)	0.62 (0.17)	−0.30 (0.17)
	<0.0001; 0.671	0.002; 0.109	0.097; 0.034
B. boreas	BUFO	NN-TYPE				0.781	<0.0001
	148.22 (24.10)	394.68 (89.53)
	<0.0001; 0.543	0.0003; 0.238
ρ	T. elegans	ELEGDIFF	SIRTDIFF	DIST	ELEVDIFF	TYPEDIFF	0.342	0.001
	−2.16×10−4 (1.76×10−5)	2.04×10−5 (4.05×10−6)	2.12×10−4 (5.54×10−5)	8.31×10−7 (2.43×10−7)	2.01×10−4 (4.93×10−5)
	0.001; 0.252	0.001; 0.030	0.001; 0.026	0.001; 0.021	0.001; 0.013
T. sirtalis	SIRTDIFF					0.449	0.001
	−6.64×10−5 (5.93×10−6)
	0.001; 0.449
B. boreas	TYPEDIFF	SNAKEDIFF	ELEVDIFF	PERIMDIFF	DIST	0.659	0.001
	−3.42×10−4 (9.00×10−5)	2.46×10−5 (7.19×10−6)	−3.01×10−6 (6.40×10−7)	−2.70×10−4 (5.16×10−5)	1.22×10−4 (4.67×10−5)
	0.001; 0.207	0.003; 0.145	0.001; 0.108	0.001; 0.102	0.011; 0.097
FST/(1−FST)	T. elegans	DIST	ELEVDIFF				0.114	0.002
	6.23×10−3 (1.78×10−3)	4.74×10−5 (1.13×10−5)
	0.001; 0.058	0.002; 0.056
T. sirtalis	DIST	ELEGDIFF	PERIMDIFF			0.352	0.001
	1.28×10−3 (2.58×10−4)	−4.01×10−3 (1.30×10−3)	−6.82×10−3 (2.36×10−3)
	0.001; 0.158	0.001; 0.139	0.009; 0.055
B. boreas	DIST					0.464	0.007
	8.86×10−4 (2.39×10−4)
	0.003; 0.464