Catriona MacCallum joined PLOS in July 2003 as one of the launch editors of PLOS Biology. Her main duties included overseeing manuscripts through peer-review on PLOS Biology and providing editorial oversight and advice for PLOS ONE. She initially studied Zoology at Edinburgh University, remaining there to do a PhD on the evolutionary ecology and genetics of speciation with Nick Barton. After further research and teaching in South Africa and Edinburgh, she joined the Elsevier journal Trends in Ecology & Evolution as assistant Editor in 1998, becoming Editor in 1999 and Managing Editor in 2001. She also took a one year sabbatical from PLOS in 2007-2008 as an invited Fellow of the Institute of Advanced Studies in Berlin. She is an active advocate for open access to all scientific information, and has given numerous talks as well as publishing articles on the topic. After 10 years, she moved from PLOS Biology to the Advocacy team in 2013. She sees her role with PLOS as a unique and challenging opportunity to help change the nature of scientific communication.