Swimming around, looking for food, big tough Opisthokonts are becoming the Dwayne Johnson of the unicellular world. There’s not as many of them as there are bacteria, but they live longer.

You are starting to grow in clumps, as a mass of cells, working together. This works because there is less chance of something else eating you.

As the outer opisthokonts get older and die off, they protect the younger ones on the inside. Teamwork.

At present, if you find a simple chemical you can use, you absorb it directly and use it, but if you find a more complex object you have to engulf it and take it apart. Some of the ‘taking apart’ chemicals leak out through your membranes, and start breaking down your food while it is still outside, which is useful.

As you demand more food, to grow bigger, it makes sense to increase the quantity of those chemicals. But are you going to espress them inside you, or outside?