Analysis of evolutionary patterns of genes in Campylobacter jejuni and C. coli

Table 2 Results for the clusters identified

Cluster	Number	Clumping	CGF under	Recombination
	of CGF	index I	selection	rate $\bar{γ}$ (p)
Blue+cyan	935	1.73	2	27.3 (-)
Red	120	4.76	15	49.7 (<0.01)
Green	103	5.40	0	33.1 (0.02)
Brown	22	16.67	13	25.4 (0.70)

The clumping index Iis described in Methods. CGFs under selection are the number of genes having a significantly negative Tajima Dstatistic. The recombination rate is the average for the cluster, and the associated p-value listed in parenthesis is for the t-test of difference to the blue+cyan cluster.