Table 3.

Rate tests between major and minor tubulin paralogs.

Major isoform	Minor isoform	Rate test (mean Chi-Sq. +/- Sdv)
Insect β1	Insect β2	5.12 +/- 3.81	n = 9
Insect β1	Insect β3	11.85 +/- 4.33	n = 9
Insect β1	Insect β4	21.34 +/- 21.15	n = 6
Insect α1	Insect α2	10.66 +/- 17.34	n = 6
Insect α1	Insect α3	71.19 +/- 9.91	n = 2
Insect α1	Insect α4	97.87 +/- 62.34	n = 4

Protein evolutionary rates were compared between major and minor tubulin paralogs resulting from ancient duplication events predating separation of insect orders, using Ha major alpha and beta tubulins as outgroups. The average and standard deviation of chi-square values for pairwise rate tests are presented (eg. Insect β1 vs. Insect β2 = (Chi-sq. Dmβ1 vs. Dmβ2 + Chi-sq. Agβ1 vs. Agβ2 + Chi-sq. Aeβ1 vs. Agβ2...)/9). In taxa with multiple copies of an isoform, rate tests are performed using the conserved isoform. The only Drosophila species included is Dm, to avoid a Dipteran skew in the results. Chi-Sq. values > 3.8 have a probability of p < 0.05; Chi-Sq. values > 5.2, p < 0.01.