The Volvocine Green Algae
The Volvocine Green Algae diverged from a unicellular Chlamydomonas –like ancestor approximately 240 mya (Herron et al. 2009). They range from simple unicellular species like Chlamydomonas reinhardtii to large complex species with thousands of cells and cellular differentiation, as seen in Volvox carteri. Intermediate forms range from simple sheets of 8-16 cells as seen in Gonium, to larger 32-64 celled spheroids as in Eudorina, and 128 celled spheroids with somatic cells as in Pleodorina. These extant forms are predicted by our character state reconstructions to be similar to evolutionary intermediates during the evolution of multicellular individuality in this lineage.