In 2003, a doctor flew to Hong Kong to attend a wedding and he brought with him a mysterious, deadly virus that he had caught from patients he was treating in Mainland, China. Unfortunately, the doctor never made it to the wedding. And he died two weeks later. But not before he had infected several other people from different countries who were staying on the same floor of his hotel. And within a month, this mysterious virus was wreaking havoc and causing panic around the world. >> But where did this virus come from and how did it spread around the globe? To solve this mystery, we will construct an evolutionary tree for similar viruses from different species in order to determine which species started the epidemic. Studying viruses that cause epidemics is just one of the many applications of evolutionary trees, which range from catching criminals to identifying the birth place of human civilization. When we construct evolutionary trees, we use genomes of present day species. To get inside into how the species have evolved from their ancestor, but can we reconstruct the genes and proteins from extinct species? >> Speaking of extinct species, when I was seven years old I saw the movie Jurassic Park, and it made me dream of one day getting to see a real life dinosaur. Fortunately, I'm not alone. Famous paleontologist, Jack Horner, has the same dream and this shared dream of ours took 1 small step toward reality when in 2007 Horner and his colleagues identified protein fragments that had miraculously survived in a T-Rex fossil for 68 million years. But because these proteins were very similar to chicken proteins, they presented the first genetic evidence for the hypothesis that birds had evolved from dinosaurs. In fact, Horner was so inspired by this discovery that he even published a book about how researchers could one day genetically modify a chicken into a real life T-Rex. >> But what in the world do have to do with these dinosaur fossils? It turns out that since all for protein sequencing make errors, some scientists, myself included, doubted whether Horner had really found any evidence of Jurassic project. But which side is correct? We hope that you will join us and decide for yourself. >> Although these instructors may appear crazy, they are not quite as mad as they look. Dr. Pavel Pevzner is a distinguished professor of computer science at the University of California, San Diego and a leading authority on bioinformatics. He's dressed this way because he sometimes thinks that he is a sheriff of bioinformatics, a frontier discipline under pinning the digital revolution in biology and personalized medicine. Dr. Phillip Compeau is an Assistant Professor of Computer Science at Carnegie Mellon University, to learn why he is dressed this way, you'll need to take this course or read the textbook, Bioinformatics Algorithms An Active Learning Approach, coauthored by the two speakers.