Molecular phylogeny
The phylogenies obtained with BEAST and MrBayes have very similar
topologies, with six distinct clades (named A to F for convenience;
BEAST topology is shown in Figs 2–5, whereas MrBayes topology is
available in Supplementary Materials SM.03). As multiple basal nodes in
the MrBayes tree are poorly supported/unsupported (PP=0.56–0.78; see
SM.03), only the topology obtained with BEAST is showed and discussed in
detail (Figs 2–5).
The BEAST topology is, therefore, as follows: clade A and B are in a
sister relationship, with high support (PP=0.94 for clade A, PP=1.00 for
clade B, and PP=1.00 for clade A+B), with the exact composition and
relationships being depicted in Fig. 3. Clade A groups 40 populations
representing 17 species, whereas the sister clade B includes 23
populations representing 10 species. The (A+B) clade is sister to the
clade that groups clades C and D. Clade C+D is highly supported (PP=0.95
for clade C, PP=1.00 for clade D, and PP=0.96 for clade C+D; Fig. 4).
Clade C consists of 31 populations representing 19 species and clade D
include 8 populations representing 7 species. The node indicating the
split between (A+B) and (C+D) is moderately supported, with PP=0.84.
Finally, clade E (PP=1.00; 21 populations representing 11 species; Fig.
5) is related to a small clade F (PP=1.00; three populations, classified
as two species Fig. 5) but with low support.
The phylogeny largely corresponds to the relationships presented by
Morek & Michalczyk (2020) (Fig. 2), but with some noticeable
exceptions. Specifically, our clades A, B and D correspond to the
previously identified clades A, B and D but are enriched with multiple
species and populations (indicated by solid arrows in Fig. 2). Clades C
and E herein correspond to clade E and C in the previous contribution,
but their positions are different (dashed and dotted arrows in Fig. 2).
Specifically, whereas in the previous study their clade E was the most
basal, it is denoted here as clade C and is a part of the ‘crown group’
in the present study. In contrast, clade denoted as clade C and sister
to clades (A+B) in Morek & Michalczyk (2020) is now denoted as clade E
and is placed in the basal polytomy. Similarly to clades A, B and D,
clades C and E in the present analysis are also enriched with new
populations/species. Finally, clade F obtained in this study is new and
is formed exclusively by new samples.