Table 5. Species recorded from more than one zoogeographic realm, i.e. evidence for recent LDD ( – the most probable realm of origin; – most probably natural dispersion; – most probably anthropogenic dispersion).
Figure 1. Approximate localities of the 127 Milnesiumpopulations analysed in this study (see Supplementary Materials SM.01 for details). Yellow circles indicate the newly analysed populations (N=83), whereas red circles stand for data retrieved from the literature (N=44).
Figure 2. Simplified Bayesian Inference time calibrated phylogenetic tree based on concatenated 18S rRNA+28S rRNA+ITS-2+COI nucleotide sequences obtained with BEAST (left) and its relation to the most recent published phylogeny of Milnesium by Morek & Michalczyk (2020) (right). The left side tree: the upper values at nodes indicate the 95% Highest Posterior Density, which is graphically presented as the blue bar, whereas the lower values provide the Posterior Probability (PP) supports. Yellow circles superimposed on nodes indicate the two calibration points used as tree priors. The dashed branches indicate phylogenetic uncertainty. The main geological eras as well as the estimated time of the Gondwana breakup (vertical grey bar) are marked. The Mya stands for Million years ago. The six main clades within Milnesium (A–F) are collapsed and their sizes indicate the number of populations within each clade in both phylogenetic trees. The percentages within the collapsed clades indicate the support for the origin of the ancestor in given zoogeographic realm (see Results for more details). See Figs 3–5 for detailed relationships within each of the main clades uncovered in this study. The right side tree: values at nodes represent PP supports and the scale bar shows the number of substitutions per site. The arrows between both trees show the relationship between clades obtained in this contribution and in the phylogeny by Morek & Michalczyk (2020). The pie chart below indicates the number of species detected in the genus Milnesium to date divided into three categories (blue – species described under the integrative taxonomy framework; green – classically described species, i.e. of which phylogenetic position is unknown; yellow – undescribed putative new species detected in this study).
Figure 3. Milnesium phylogeny: clades A and B reconstructed using the time calibrated Bayesian Inference based on concatenated 18S rRNA+28S rRNA+ITS-2+COI nucleotide sequences obtained with BEAST (see Fig. 2 for the entire tree). Values at nodes represent Posterior Probability (PP) supports and the scale indicates the time before present in Millions of years. Black vertical bars right to the population codes encompass species delineated using both phylogeny and morphology, whereas thin grey vertical lines indicate putative species suggested by the bPTP analysis alone and that did not agree with the integrative species delineation; numbers within vertical black bars are running species numbers (see Results for more details on species delineation). Further right, zoogeographic origin, climate type and reproductive mode are indicated by numbered and differently coloured squares. Colour and number coding are explained in the legend in Fig. 5.
Figure 4. Milnesium phylogeny: clades C and D reconstructed using the time calibrated Bayesian Inference based on concatenated 18S rRNA+28S rRNA+ITS-2+COI nucleotide sequences obtained with BEAST (see Fig. 2 for the entire tree). Values at nodes represent Posterior Probability (PP) supports and the scale indicates the time before present in Millions of years. Black vertical bars right to the population codes encompass species delineated using both phylogeny and morphology, whereas thin grey vertical lines indicate putative species suggested by the bPTP analysis alone and that did not agree with the integrative species delineation; numbers within vertical black bars are running species numbers (see Results for more details on species delineation). Further right, zoogeographic origin, climate type and reproductive mode are indicated by numbered and differently coloured squares. Colour and number coding are explained in Fig. 5.
Figure 5. Milnesium phylogeny: clades E and F reconstructed using the time calibrated Bayesian Inference based on concatenated 18S rRNA+28S rRNA+ITS-2+COI nucleotide sequences obtained with BEAST (see Fig. 2 for the entire tree). Values at nodes represent Posterior Probability (PP) supports and the scale indicates the time before present in Millions of years. Black vertical bars right to the population codes encompass species delineated using both phylogeny and morphology, whereas thin grey vertical lines indicate putative species suggested by the bPTP analysis alone and that did not agree with the integrative species delineation; numbers within vertical black bars are running species numbers (see Results for more details on species delineation). Further right, zoogeographic origin, climate type and reproductive mode are indicated by numbered and differently coloured squares. Colour and number coding are explained in the legend at the bottom of the tree.
Figure 6. The summary and interpretation of distribution patterns of Milnesium species recovered in this study. Species with limited ranges = species found only in a single zoogeographic realm; widespread species = species found in more than one zoogeographic realm (i.e. suggesting recent Long Distance Dispersal, LDD); ‘inclusion species’ = species that were found in a different zoogeographic realm than the majority of species in a given clade (i.e. suggesting ancient dispersal); SSD = Short Distance Dispersal (refers to species found in localities close to the borders of adjacent zoogeographic realms). Overall, there were 86% species showing no evidence for natural LDD and 14% species suggesting natural LDD (mostly ancient, only rarely recent).