TABLE 2.

Testing for phylogenetic clustering of B. garinii clpA alleles by sampled species^a

Statisticb	Observed mean (95% CI)	Null mean (95% CI)	P value
Association index	2.4 (1.5–3.2)	2.3 (1.9–2.7)	0.58
Parsimony score	16.1 (14–18)	15.9 (13.8–17.7)	0.52
Monophyletic clade size
Gray squirrel	2.3 (1–3)	2.5 (2–4)	0.95
Tick	6.6 (6–8)	4 (2.9–6.2)	0.09

^aSee the maximum-likelihood tree shown in Fig. 2.

^bThe tests used three test statistics described previously (52). All three test statistics test the null hypothesis that the sampled species are distributed randomly among tip nodes. Association index, a measure of imbalance of internal nodes; parsimony score, the number of state changes in phylogeny; monophyletic clade size, a measure of the size of the clade sharing the same trait at the tips.