ABSTRACT
In this chapter, we examine future directions for research on the evolution of multicellularity. Specifically, we review open questions about the evolution of multicellularity from a range of disciplinary perspectives, including philosophy, natural history, phylogenetics, biophysics and astrobiology. Further, we examine major outstanding questions about the evolution of multicellularity itself, including the origin and subsequent evolution of multicellular life cycles, the role of organismal size in the evolution of multicellular complexity, the origin of development, and the role of environmental drivers and niche construction over geological timescales. Finally, we highlight recent progress and the future potential of comparative, experimental, and theoretical approaches to studying multicellularity. There has never been a better time to study the evolution of multicellularity—recent developments in life science technologies have dramatically expanded experimental opportunities, yet the field remains small enough that breakthrough discoveries made by new members of the community are not just possible, but expected.
