“Let’s stay together.” – Al Green

Some of the biggest questions in evolutionary biology deal with the origin of life. For example, if I go back one generation, I find my parents. Two generations, my grandparents. Ten generations are human beings who may or may not have looked like me. Five hundred thousand are, oh, I don’t know. Maybe a bipedal hominid? Anyway, if we continue going backward like this, we inevitably get to time zero and encounter some big-time questions that can really cause a brain to cramp up.

One of these major questions that can cause someone to drool on their shirt in amazement of evolution is the transition of life from unicellular, sovereign entities to cooperative multicellular organisms. A recent paper by Ratcliff et al. (2012) from the University of Minnesota posits that the first step towards multicellular organisms is cellular clustering; they then proceed to evolve clustering in unicellular yeast and ask questions about the clusters.


Premise: Bigger things settle in solution faster than smaller things.

(Oversimplified) Materials: Unicellular yeast (Saccharomyces cerevisiae), test tubes, solution that the yeast can eat, time

Step 1: Suspend unicellular yeast in solution in a test tube.

Step 2: Wait 45 minutes.

Step 3: Transfer the cells at the bottom of the tube to a new tube with fresh solution.

Step 4: Return to Step 2 60 times.

Step 5: Look in microscope. Continue reading