Pennisi figure
Top left: Chlamydomonas (Andrew Syred/Science Source). Top right: Gonium (Frank Fox/ Science Photo Library). Bottom: Volvox (Wim van Egmond/Science Photo Library).

A news item by Elizabeth Pennisi in Science mentions our work experimentally evolving multicellularity in Chlamydomonas reinhardtii:

[Will Ratcliff’s snowflake] yeast results weren’t a fluke. In 2014, Ratcliff and his colleagues applied the same kind of selection for larger cells to Chlamydomonas, the single-celled alga, and again saw colonies quickly emerge. To address criticism that his artificial selection technique was too contrived, he and Herron then repeated the Chlamydomonas experiment with a more natural selective pressure: a population of paramecia that eat Chlamydomonas—and tend to pick off the smaller cells. Again a kind of multicellularity was quick to appear: Within 750 generations—about a year—two of five experimental populations had started to form and reproduce as groups, the team wrote on 12 January in a preprint on bioRxiv.