Working together can have huge advantages for the people, animals, plants, and cells you find in them. Some algae try to cheat, but that turns out to be working against them.
The researchers studied that cheat in a type of green algae: a simple multicellular organism. Because among these algae there are individuals who enjoy the benefits of living in a group, but they themselves excel.
Algae species contain two types of cells: reproductive cells, which are supposed to reproduce, and body cells, which are not supposed to reproduce. Normally these cells work together, and each has its own task, but if there are certain mutations in these body cells, they suddenly start multiplying. Since these cells are the majority, you might think: at any given time you will only have this type of puppet cell in a colony. But this is not the case: in nature they still work together.
So there must be a downside to this sneaky behaviour. The researchers exposed both cheater algae cells and normal algae cells to harsh conditions and witnessed many deaths among cheaters. So the burden of this cheating appears to be greater than what the cell gains, and this may explain why cells start working together to form multicellular organisms in the first place.