Nova: Here is a strange thought experiment. Take the entire instruction manual for building you, all three billion letters of it, and realize it is written in an alphabet with only four characters. A, C, G, and T. Now ask yourself, how would you even begin to read it?

Nova: Before we open the code editor, we have to talk about the book, because it flips the usual story. The centerpiece here is Bioinformatics Algorithms: An Active Learning Approach, by Pavel Pevzner and Phillip Compeau.

Nova: Weeks one and two ask a simple sounding question. Where in the genome does replication begin? Every cell has to copy its DNA before it divides, and that copying starts at a special location called the origin of replication, or oriC in bacteria.

Nova: Weeks three and four switch to a second mystery. Which DNA patterns act like molecular clocks? Some short sequences are so important that they barely change over millions of years, while everything around them mutates.

Nova: Here is what makes this course and book genuinely unusual. They are built around something called an interactive textbook, not just video lectures.