One of the most important discoveries of the Game of Life was made by Wainwright, who examined the effect of adding extra cells to pre-defined stable configurations, such as the one illustrated below.

Check that this is a stable configuration by clicking on the Animate button and then follow the instructions given underneath.

Click on the Init button and this time place the virus on any empty square, other than one where two empty lines cross. Watch the chaotic evolution of the pattern. In fact, if the pattern was infinite this virus would cause its entire destruction. However, in our example, once again, due to problems of finitude, the pattern may not necessarily become extinct, but its existing perfect organisation is destroyed completely .

The most immediate practical application of this could be the design of circuits, which are capable of self-repair. It could also have important implications on cell growth in embryos, the replication of DNA molecules, the operation of nerve nets, genetic changes in evolving populations and so on. 

Now try and construct some stable patterns in the following window, using the ones you are already familiar with as a starting point. Then, investigate what happens to each pattern if you add a virus to it.