This project aims to understand the origins of biological individuals in evolution. For instance, how did bacteria-like unicellular organisms transform into multicellular organisms like us? Previous attempts answered this question by focusing on the 'shift' in levels of selection occurring during events of transitions in individuality. This project will take a different perspective. It will rely upon philosophical analysis and formal models to articulate the equally important, yet often neglected, 'shift' in levels of high-fidelity inheritance that occurs during such transitions. The models will then be translated into an experimental design and pilot study to demonstrate that philosophy can have an essential shaping role in biology.