Adaptive Evolution Hotspots at the GC-Extremes of the Human Genome: Evidence for Two Functionally Distinct Pathways of Positive Selection

Table 2

Characterisation of gene subsets with differing intron/exon numbers and intron length, in terms of evolutionary rate and gene expression. Spearman correlation coefficient (= 0.58, 𝑃<2.0×10⁻¹⁶) was calculated for gene subgroups greater than 2SD (intron length/number and intron number/length) from the mean.

	Short and higher intron		Long and higher intron		P-value^†
	length/number		number/length
	Mean	Median	Mean	Median
Ka/Ks	0.19	0.17	0.054	0.080	<2×10^−16
Breadth	10.27	9	23	11.52	0.019
SAGE	114.44	34.66	30.05	39.91	0.021

^†P-value of nonparametric Mann-Whitney test.