Impending university exams have prevented me from posting much – so here is a lovely image of Pseudomonas to make up for it! Pseudomonas are a very common group of bacteria found in the soil (and on us!) they are studied by scientists investigating all sorts of things, from how they affect the condition of the soil and crop diseases to experimental evolution. Also certain species can infect humans and cause serious problems if they have weakened immune systems. They also are used to study social evolution – why and under what conditions organisms carry out social interactions like cooperation and spite. More on how bacteria can be spiteful later….