TABLE 2

Testing for phylogenetic clustering of B. garinii clpA alleles by sampled speciesa

StatisticbObserved mean (95% CI)Null mean (95% CI)P value
Association index2.4 (1.5–3.2)2.3 (1.9–2.7)0.58
Parsimony score16.1 (14–18)15.9 (13.8–17.7)0.52
Monophyletic clade size
    Gray squirrel2.3 (1–3)2.5 (2–4)0.95
    Tick6.6 (6–8)4 (2.9–6.2)0.09
  • a See the maximum-likelihood tree shown in Fig. 2.

  • b The 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.