The jump to multicellular life seems to be pretty easy, actually. To quote Wikipedia:
Multicellularity has evolved independently dozens of times in the history of Earth, for example once for plants, once for animals, once for brown algae, but perhaps several times for fungi, slime molds, and red algae.
The wikipedia source-link
It seems to be remarkably easy for eukaryotes, with their excessive number of genes (probably accumulated via drift and non-adaptive processes) which can be co-opted for cell-to-cell communication. There are those that argue that prokaryotes are too heavily optimized for efficient fast reproduction to make huge multicellular complexes- though it turns out that they actually do specialize themselves a bit when they are growing in colonies or biofilms to provide for the colony as a whole.
The jump to multicellular life seems to be pretty easy, actually. To quote Wikipedia:
It seems to be remarkably easy for eukaryotes, with their excessive number of genes (probably accumulated via drift and non-adaptive processes) which can be co-opted for cell-to-cell communication. There are those that argue that prokaryotes are too heavily optimized for efficient fast reproduction to make huge multicellular complexes- though it turns out that they actually do specialize themselves a bit when they are growing in colonies or biofilms to provide for the colony as a whole.