1. Department of Mathematics, Clarkson University, Potsdam, New York 13699, USA
2. Department of Mathematical Sciences, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, USA
3. Department of Mathematics, University of California, Los Angeles, Los Angeles, California 90095, USA
4. Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom
5. CABDyN Complexity Centre, University of Oxford, Oxford OX1 1HP, United Kingdom
6. Department of Zoology, University of Oxford, Oxford OX1 3PS, United Kingdom