Merlin studied at Cambridge University, where he was a scholar of Clare College. He received a triple First in his MA degree in the Biological Sciences, and a First with distinction in his MSci degree in the History and Philosophy of Science. He was awarded the University Lipton Prize for best performance in History and Philosophy of Science, the Clare College Godwin Prize for the Life Sciences, and the Clare College Greene Cup, awarded for academic excellence to one student a year. Following his masters degree, he received a Cambridge University scholarship for a PhD in Tropical Ecology and worked on mycorrhizal fungal networks in Panamanian tropical forests, based at the Smithsonian Tropical Research Institute, where he held a predoctoral Smithsonian Research Fellowship. He was awarded his PhD in June 2016. As well as his work in Panama, he has spent time doing research in labs in Lund (Sweden), Marburg (Germany), Cambridge, and London. He is a pianist and piano accordionist, and is a member of the London-based Gentle Mystics. His publications are listed here.