Physical Influence on the Trajectory of Nascent Multicellular Evolution*

The evolution of multicellularity transformed life on earth by setting the stage for all higher orders of organismal complexity; yet many critical aspects of this transition remain poorly understood. Using experimental evolution of snowflake yeast^1,2, we study the role of physics in this fundamental evolutionary process. Under selection for large size, nascent multicellular snowflake yeast clusters evolve increased fitness along trajectories that are highly physically efficient. Further, we find that a physically challenging environment impedes the evolution of increased cluster fitness. Thus we demonstrate the significant role played by physical constraints in the evolution of nascent multicellularity.

¹W. Ratcliff et al. 2012. PNAS. 109:1959–1600.

²W. Ratcliff et al. 2015. Nature Communications. 6:6102.