Further Applications of EDMA - An Invariant Approach to Statistical Analysis of Shapes - page 280

Figure 7.10 Results of the bootstrap analysis of the phylogenetic signal in the ateline
data. The clustering based on morphometrics (a) differs from the cladogram (b) in the
affinities of Lagothrix, Ateles, and Brachyteles. The nodes of the trees are labeled with
marginal bootstrap proportions (500 resamples). The results indicate the presence of a
strong “alternative” signal in the data (see text).
hypothesized to be a sister taxon of the other genera.
Within the Lagothrix-Ateles-Brachyteles clade, however, the phylo-
genetic signal is very weak. The bootstrapped morphometric data only
cluster Ateles and Brachyteles together 3.8% of the time (the correct
genealogy), while Lagothrix and Ateles are clustered together the
remainder of the time (96.2%). Because this high bootstrap probability
is associated with a difference in tree topology, it suggests a very strong
signal that is not a phylogenetic signal, but is some kind of alternative
signal. Cole et al. (2000) hypothesize that the strong shape similarity
between Lagothrix and Ateles is due to a functional similarity related
to diet, which is correlated with variations in facial structure.