Readers who are unfamiliar with biology, genetics, and evolution will find chapter 2 a great help. Complexity is often confused with order, but the two are not the same. The complexity that this web site is concerned with is perhaps better called information. The genes in life contain information just like an encyclopedia contains information. The models developed in chapters 5 and 6 calculate the likelihood that this information can evolve.
New information requires new genes.
So in effect the models developed on this site calculate the probability that a new gene can evolve. New genes are required to create complexity. Probability and information theory will be used on this site to analyze the likelihood associated with the evolution of new genes. Because information is akin to language some simple examples with strings of letters will help clarify what complexity is and how it evolves. It contains no information.