All things considered, we're pretty happy that life evolved into multicellular organisms — but what was the advantage to this shift? The answer may lie in brewer's yeast. Beyond just giving us the wonderful liquid that is beer, Saccharomyces cerevisiae has an interesting feature: it's far more efficient at certain tasks when in groups. Could yeast social networking really be the origin of our complicated bodies, with their trillions of cells?
Researchers put the yeast through its paces in a very straightforward task: breaking down and transporting sugar, so that it could eat, survive and multiply. In order to devour sucrose, the yeast has to split it into glucose and fructose, and then get it to the cell membrane where it can be absorbed. The problem is that both of these activities are incredibly inefficient for a single celled organism on its own — the researchers calculated that a single cell would only capture 1% of the sugar it broke down.
However, once the yeast cells started gathering in clumps, the efficiency improved dramatically. Because sugar was being broken down all over the place, it was much easier for each yeast cell to absorb the stuff. This allowed a higher chance for all cells to grow and divide. It's a possible explanation for the evolutionary advantage of cells grouping with others, rather than hanging around on their own.