Extended Data Fig. 2: Characterizing the life-cycle of the ancestral (microscopic) and evolved (macroscopic) snowflake yeast.

a, During the ~24-hour growth cycle, snowflake yeast compete for growth and reproduction in 10 mL of YPED (250 RPM at 30 °C). At the end of the growth phase, we select for larger group size via settling selection. While there is a theoretical maximum survival rate of 15% (that is, if all of the cells survived settling selection), we only transfer the bottom 50 µl of pellet biomass regardless of how many cells settle, creating an arms race that favours the fastest groups within the population. Our measurements of the number of cellular generations per day in Fig. 1a suggests about 3% of the cells survive from one day to the next on average. b, Both the microscopic (ancestral) and macroscopic (t600) snowflake yeast clusters have a life cycle, reproducing during the growth phase. c, Consistent with entanglement producing tough groups, macroscopic snowflake yeast release mostly microscopic propagules, possibly from branch tips at the exterior of the group, where the opportunity for entanglement is minimal. Despite the presence of many small propagules, most of the biomass in the population is contained within macroscopic clusters. The open circles represent the biomass-weighted mean size, which is the average sized group the mean cell finds itself in. A total of 14,313 clusters were analysed for the t0 time point, and 1,603 clusters were analysed for the t600 time point, across 0, 3, 6, 12, and 24-hour time points.