Extended Data Fig. 1: Summary statistics for the phylostratigraphic maps of F. serratus, F. distichus, Ectocarpus (species 7), L. digitata and S. polyschides.

Taxonomic ranks and the number of genes assigned to each rank (phylostratum [PS] - gene age ranks) in brown algae: A, F. serratus; B, F. distichus; C, Ectocarpus; D, L. digitata; and E, S. polyschides. Evolutionarily younger genes have a higher gene age rank and vice versa for evolutionarily older genes. Lineage information is detailed in F. serratus (A), and is the same across all five species for PS 1 (cellular organisms) to 7 (Phaeophyceae; the evolutionary transition to complex multicellularity).