We currently see a vast amount of information being generated as a result of experimental work in biomedicine. Particularly impressive is the development in DNA sequencing. As a result, we are now facing a new era of genomics where a lot of different species, as well as many different human individuals, are being analysed. There are many important biological questions being addressed in such genome-sequencing projects, including questions of medical relevance. A critical technical part of all these projects is computational analysis. With the large amount of sequence information generated, computational analysis is often a bottleneck in the pipeline of a genomics project. Therefore, there is great demand for individuals with the appropriate computational competence. Ideally, such individuals should not only be proficient in the relevant mathematical and computer scientific tools, but should also be able to fully understand the different biological problems that are posed. This book was partly motivated by the urgent need for bioinformatics competence due to recent developments in genomics.

A student or scientist may enter into bioinformatics from different disciplines. This book is written mainly for the biologist that wants to be introduced to computational and programming tools. There are certainly books out there already for that type of audience. However, I was attracted by the idea of assembling a book that would cover a large number of relevant biological topics and, at the same time, illustrate how these topics may be studied using relatively simple programming tools. Therefore, an important principle of the book is that it will attempt to convince the reader that relatively simple programming is sufficient for many bioinformatics tasks and that you need not be a programming expert to be effective. Another important principle of the book is that I wanted the bioinformatics examples to be very practical and explicit. Thus, the reader should be able to follow all the details in a procedure all the way from a biological problem to the results obtained through a technical approach. As one demonstration of this principle, all files and scripts mentioned in this book are available for download at www.cambridge.org/samuelsson. This means the reader is able to try it all out on his/her own computer. I also wanted this book to illustrate the interdisciplinary nature of bioinformatics.