Selection is an important part of evolution, where a population adapts to its environment. In his book "Selection" Graham Bell comments: "It is the successive selection of slight improvements that makes it possible for apparently improbably transformations to occur so rapidly." He also describes a game which illustrates this concept very well. It is a word game where the word "WORD" is changed, one letter at a time, into the word "GENE". If each move, a letter is changed at random, assuming that we can change one letter a second and have an average amount of luck, it will take between two and three days to get the word "GENE". In the next version of the game two new rules are added - only meaningful English words are allowed and any variants that are more like the word GENE (have more letters in the right place) replace any that are less similar. This means that the selection element of evolution has been added. Using these rules means that there are only a few steps of words taking "WORD" to "GENE" and this should be completed in a couple of minutes.