Craig Moritz


Professor & Laureate Fellow, Research School of Biology, Australian National University and Director, Centre Biodiversity Analysis, Australia

Title: Connecting speciation with macroevolution using phylogenomics

Abstract: With ready access to sequence data from 1000’s of loci, we can have the potential to obtain a much higher resolution understanding of speciation processes, and how different speciation dynamics translate to macroevolutionary outcomes. We have developed exon-capture systems that yield genome-scale sequence data, with dense sampling of intraspecific (phylogeographic) lineages through to large clades of species. This approach, combined with phenotypic analyses reveals a high incidence of truly cryptic diversification, which can span millions of years as envisaged under the “Protracted Speciation Model” (PSM). As envisaged by the PSM, we also observe evidence of lineage fusion and/or introgression leading to strong cytonuclear discordance. These observations have several implications for macroevolutionary analyses. First, sampling independently evolving lineages below and above the level of taxonomically recognized species can provide richer insights into diversification processes. Second, with such dense sampling of closely related lineages, care must be taken to use appropriate (ie. Multi Species Coalescent) methods to properly estimate the branch lengths on which many macroevolutionary inferences are based. Third, evidence for often extended speciation processes and/or reticulation should challenge use of macroevolutionary models that assume instantaneous and irreversible speciation.