IS PHENOTYPIC EVOLUTION PREDICTED BY DIRECTIONS OF HIGH TRAIT VARIATION DURING ANAGENESIS AND CLADOGENESIS?

The balancing act of genetic constraints, variation, and selection pressures direct the tempo and mode of phenotypic change. A growing body of work shows that the direction of phenotypic change within lineages tends to be in directions of above-average variation, or evolvability. It is less well known, however, whether phenotypic change during speciation events is also predicted by directions of high variance and how they may change post speciation. This is partly because genetic variation-covariation matrices are difficult to obtain for a time series within a lineage, and even more so for among closely related species. We capitalize on the clonal nature of Bryozoa to disentangle phenotypic variance-covariances from genetic variance-covariance and to study if and how directions of high genetic variation predict phenotypic change before, during and after cladogenetic events. We focus on four species within the genus Microporella all from New Zealand and that have a well-preserved fossil record spanning over 2 million years. We measure phenotypic change of the autozooid, avicularia, and ovicell to explore how these modules act independently and integratively.