Colonial hypothesis
Multicellularity may have arisen when cells that a dividing protist produced remained together. Cell invagination could have formed a second cell layer. This hypothesis is supported by the colonial organization of some protozoa. Led primarily to RADIAL ANIMALS
Synctial hypothesis
1: Large syncytial protist
2: Cell boundaries formed
3: Bilateral ancestor
Multicellularity could have arisen when plasma membranes formed within the cytoplasm of a large, multinucleate protist. Multinucleate, bilateral ciliates support this hypothesis. Led primarily to BILATERAL ANIMALS
2: Cell boundaries formed
3: Bilateral ancestor
Multicellularity could have arisen when plasma membranes formed within the cytoplasm of a large, multinucleate protist. Multinucleate, bilateral ciliates support this hypothesis. Led primarily to BILATERAL ANIMALS