School of Biological Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. kwolstencroft@cs.man.ac.uk|School of Biological Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. kwolstencroft@cs.man.ac.uk|School of Biological Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. kwolstencroft@cs.man.ac.uk|School of Biological Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. kwolstencroft@cs.man.ac.uk|School of Biological Sciences, Michael Smith Building, University of Manchester, Oxford Road, Manchester, M13 9PT, UK. kwolstencroft@cs.man.ac.uk