Acknowledgements

We would like to thank J. Kovaliski for clarification on the data used in his publication. We are grateful to E. Holmes, J. Mahar and J. Kovaliski for the useful and stimulating conversations on this study and K. Helbig and Lindy Lumsden for comments on the draft of the manuscript. We would like to thank D. Kühnert, A. Gavryushkina and R. Bouckaert for clarifications on important aspects of their models and their implementation in BEAST2. This project was partly funded by the Centre for Invasive Species Solutions (project PO1-B-002).
Computer simulations were partly supported by CIPRES (http://www.phylo.org)