However, in their analysis of lake-specific morphospace, where the angles of PCs were compared between lakes, differences did exist between Tanganyika and Victoria for total body shape on PC1 (i.e., Mmax), which makes any interpretation from the ordered-axis plots approach (i.e., combined morphospace) questionable for total body shape in these two assemblages (see Figure 3. in Young et al., [1]).
RRTs were performed among these three assemblages, as well as between all neobatrachians versus non-neobatrachians.
These three assemblages were characterized by different seagrass or meadow structure, thereby creating three distinct seagrass habitats.
Overall, the bovid fauna does not provide strong evidence for any major evolutionary turnover taking place in the time between the two assemblages [36].
Formally, this tests whether the angles between two assemblages' Mmax axes, 2-D planes, and 3- and 4-D spaces of morphological divergence are more different than the angles between two random samples of either single assemblage.
We then tested the null hypothesis that the angle between two assemblages could result from the random subdivision of either assemblage, i.e. that the assemblages are 'the same'.
First, we calculated the 95% confidence interval (CI) for the angle between two assemblages by re-sampling 100 specimens of each assemblage with replacement and calculating the angle between them 700 times.
When these 125 points are plotted in a two dimensional x-y space, the intercept and slope of a simple linear regression of y on x statistically distinguish between the four possible arrangements of the two assemblages along that axis of the morphospace.
Similarly, assemblage structure was most dissimilar between these two areas, each area harbouring a distinct macrofaunal community.
Two assemblages were considered to be diversifying along non-parallel axes if the lower 95% CI for the between assemblage angle was greater than the larger of the two upper 95% CI for within assemblage estimates.
