Fig. 5

Phylogenetic relationships of four types of mating systems (Table 1) of Volvox africanus (homothallic) and V. reticuliferus (heterothallic), as inferred from internal transcribed spacer region 2 of nuclear ribosomal DNA. UTEX 2907 originating from Australia (https://utex.org/) lacks information of sexual reproduction (Nozaki et al. 2015a), but it was classified as V. reticuliferus based on vegetative morphology and phylogeny (Nozaki et al. 2015a). The tree was constructed by ML method (based on T92 + G model). The alignment is available in TreeBASE (Vos et al. 2010, 2012; ID 28191). Branch lengths are proportional to the genetic distances, which are indicated by the scale bar above the tree. Numbers on the left or right side at the branches represent bootstrap values (≥ 50%, based on 1000 replicates) obtained with the ML analysis or posterior probabilities (≥ 0.95) of Bayesian inference, respectively