TABLE 2.

Tests of niche divergence and conservatism.

	PC1	PC2	PC3
Y. valida-Hybrid pops.
Observed difference	4.3165*	1.367*	1.0301*
Null distribution	4.4744–4.6540	0.7710–1.0356	0.5880–0.7087
% variance explained	43%	26%	13%
Y. capensis-Hybrid pops.
Observed difference	4.4887	2.9678*	0.4564*
Null distribution	4.3197–4.5314	2.3443–2.4765	0.0520–0.1471
% variance explained	60%	20%	11%

Observed differences in the climatic niche of the hybrid populations and parental species on each PC axis are compared to the middle 95th percentile of the null distribution of the differences between their environmental backgrounds. Bold values indicate niche divergence. *Significance level, p < 0.05.