Table 1.

SNP Density in Intronless and Intron-Containing Genes.

	Intronless Genes	Intron-Containing Genes
SNP density in real ESEs	≈0.044	≈0.047
Mean SNP density in simulated ESEs	≈0.046	≈0.051
Normalized SNP density $\left(\frac{real – simulated}{simulated}\right)$	≈−0.028	≈−0.078
One-tailed P value from empirical distribution	≈0.395	≈0.106
Sample size	157 data points (344 genes)	5,845 data points (10,337 genes)