It's a tough life being an E. coli bacterium. Not only do you have to grow and multiply, but there's all those other millions of bacteria to compete with. But there's one sure-fire way to beat the competition – evolution. All it takes is a change in an individual bug's DNA that gives it a competitive edge over the others, for example by multiplying a bit faster. These coloured blobs are representations of 'families', or clones, growing from two different types of individual bacteria (shown as blue and yellow) as they colonise the gut of a mouse. The thin point on the left side of each blob is the founder bacterium, and the shapes grow and shrink as the fortunes of each clone wax and wane. By studying how populations of bacteria in the gut change over time, researchers are getting a handle on the complex processes that drive evolution.
Written by Kat Arney
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