Characterizing and comparing the covariance or correlation structure of phenotypic traits lies at the heart of studies concerned
with multivariate evolution. I describe an approach that represents the geometric structure of a correlation matrix as a type
of proximity graph called a Correlation Proximity graph. Correlation Proximity graphs provide a compact representation of
the geometric relationships inherent in correlation matrices, and these graphs have simple and intuitive properties. I demonstrate
how this framework can be used to study patterns of phenotypic integration by employing this approach to compare phenotypic
and additive genetic correlation matrices within and between species. I also outline a graph-based method for testing whether
an inferred correlation proximity graph is one of a number of possible models that are consistent with a “soft” biological
hypothesis.
Keywords Multivariate evolution - Integration - Modularity - Graphical model - Proximity graphs