Bio/Recursion introduces topics in programming, computer science, and bioinformatics via examples in the R programming language. While often associated with statistics, Bio/Recursion employs R's algorithmic capabilities to implement and visualize several fascinating methods, ranging from DNA alignment to drawing fractal trees.Recursion (self-reference) provides a central theme, with topics spanning searching, sorting, data structures, proofs, fractals, and important bio-informatics algorithms. Along the way, over 100 color illustrations and 150 code blocks illuminate the text, and dozens of exercises challenge the readers' imagination.