Figure 1.
Chronogram reconstructed under BEAST and distribution of Agnotecous species.
On the chronogram, branches shown as thick black lines indicate posterior probabilities ≥0.95. When different from 0, degrees of sympatry are indicated below branches. Grey vertical bars indicate morphogenesis episodes and dry periods (after [66]).The marginally significant case of diversification rate shifts detected with apTreeshape is indicate by an arrow, and the distribution of yule estimator of diversification for all trees the genus and clade B2 is shown. Hypothetical areas (in km2) are given on the right of the taxa names, and species are colored and numerated according their respective distribution. On the maps, the distribution of ultramafic rocks and corresponding metalliferous soils is indicated in grey (after [9]).
Figure 2.
Species-level log lineages-through-time (LTT) plot for Agnotecous (excluding infra-specific data).
Two minor increases in diversification rates around 3.5 Ma and 2 Ma are showing, but likelihood analyses reject the null hypothesis that diversification rates in Agnotecous have been constant through time.
Figure 3.
Degree of geographical overlap plotted as a function of relative age in the genus Agnotecous.
Each point represents a node in the species phylogeny in Figure 1. Linear regression yielded low intercept (0.02170<0.5) and positive slope (0.01244), suggestive of allopatric speciation, but values are not statically significant (P-value = 0.462>>0.05).
Figure 4.
Correlation between the proportion of cases showing zero overlap and the proportion of range overlap.
Using the Phillimore et al., 2008 method, allopatric speciation is suggestive but values are not statically significant (P-value = 0.2746>>0.05).
Figure 5.
Relationship between areas and ages of species.
The negative relationship between area and age of species indicates a geographical range expansion.