Table 4. The least-squares regressions of frequencies of individuals bearing a specified network or SNP vs. latitude for the populations indicated in Table 1 from the frequency and sample size data given in Table 4.

Network/SNP	Genes	Intercept	Slope	Quadratic Term	R2
65_1	TYRP1, TYR, VDR	0.752	–0.0074**	n.s.	0.70
70_1	TYRP1	0.977	–0.0082***	n.s.	0.76
rs1042602	TYR	0.890	0.0065*	n.s.	0.56
70_5	VDR	0.848	n.s.	–0.0002*	0.53
70_5–Af	VDR	0.920	–0.0027**	n.s.	0.68
65_2	VDR, MC1R, SLC24A5, SLC45A2	−0.066	0.0200***	n.s.	0.84
70_4	VDR	0.608	0.0104*	–0.0007*	0.73
70_4–Af	VDR	0.858	n.s.	n.s.	0.15
rs4073729	VDR	0.858	n.s.	–0.0002*	0.50
rs4073729–Af	VDR	0.942	–0.0023*	n.s.	0.61
rs2228478	MC1R	0.741	0.0066**	–0.0005**	0.85
rs2228478–Af	MC1R	0.877	n.s.	n.s.	0.21
rs3212369	MC1R	0.575	0.0063**	n.s.	0.59
rs1426654	SLC24A5	0.579	0.0130**	–0.0007*	0.80
rs1426654–Af	SLC24A5	0.810	n.s.	n.s.	0.24
rs16891982	SLC45A2	−0.136	0.0209***	n.s.	0.86
65_3	MC1R	0.363	0.0125***	–0.0005**	0.91
65_3–Af	MC1R	0.511	0.0064**	n.s.	0.69
65_4	VDR	0.983	n.s.	n.s.	0.29
65_5	VDR	0.462	n.s.	n.s.	0.36
65_6	VDR	0.671	n.s.	n.s.	0.00
65_7	MC1R	0.728	n.s.	n.s.	0.06

^*Significant with P ≤ 0.05, ** significant with P ≤ 0.01, *** significant with P ≤ 0.001. SNP, single nucleotide polymorphism; n.s., not significant; –Af, the sub-Saharan African populations were excluded from the regression analysis.