Table 2.

The effects of the ages at which pairs of paralogs are expressed on $p_{\mathrm{N}}/p_{\mathrm{S}}$, $d_{\mathrm{N}}/d_{\mathrm{S}}$, and gene age (in millions of years).

Species	N	$\mathrm{\Delta }{d}_{\mathrm{N}}/d_{\mathrm{S}}$	$\mathrm{\Delta }{p}_{\mathrm{N}}/p_{\mathrm{S}}$	$\mathrm{\Delta }$Age
Mosquito	13,940	0.38***	0.99***	−117***
Fruit fly	36,366	0.0055***	0.0068	−4.0*
Mouse	10,644	6.2***	2.7***	−5300**
Human	30,954	1.7***	1.2	−177***

N is the number of pairs of paralogs compared. Entries in the table are the regressions of the difference in the statistic on the difference in REA for the pairs. Significance was determined using the Spearman rank correlations (two-sided tests, not corrected for multiple tests). Exact p values are given in Supplementary Table 1.

*p < 0.05, **p < 0.01, ***p < 0.001.