Feed Me, Seymour

The transition from single-celled life to multicellularity is one of the most important biological transitions in the history of evolution of life on Earth, says Not Exactly Rocket Science's Ed Yong. There are two ways that this can be accomplished — single cells could merge together, as when individual slime molds join together to form "mobile slugs," or cells can remain attached to each other as they multiply, as choanoflagellates do, Yong says. But even as we know the how of multicellular evolution, we still don't really understand why this happens — until now. Harvard researchers recently published a study in PLoS Biology suggesting that by sticking together, cells learned that they could become better at finding food. "The multicellular life was a well-fed one," Yong says. Working with Saccharomyces cerevisiae, the researchers found that if they tweaked a single gene — which governs whether the cells stay together or break apart after they multiply — they could create "a sociable clumpy strain" of the yeast in the lab, Yong says. And they also found that this clumped strain was more efficient at breaking down sucrose than the same number of single yeast cells, and could grow in lower concentrations of sugar. "By joining forces, cells could more effectively absorb dwindling food supplies from their environment. ... Those advantages could have given early multicellular pioneers an edge over their single-celled cousins," he adds.