This course begins a series of classes illustrating the power of computing in modern biology. Please join us on the frontier of bioinformatics to look for hidden messages in DNA without ever needing to put on a lab coat.
In this course, we will see how evolutionary trees resolve quandaries from finding the origin of a deadly virus to locating the birthplace of modern humans. We will then use methods from computational proteomics to test whether we can reconstruct Tyrannosaurus rex proteins and prove that birds evolved from dinosaurs.
In the first half of the course, we will discuss approaches for evolutionary tree construction that have been the subject of some of the most cited scientific papers of all time, and show how they can resolve quandaries from finding the origin of a deadly virus to locating the birthplace of modern humans.
In the second half of the course, we will shift gears and examine the old claim that birds evolved from dinosaurs. How can we prove this? In particular, we will examine a result that claimed that peptides harvested from a T. rex fossil closely matched peptides found in chickens. In particular, we will use methods from computational proteomics to ask how we could assess whether this result is valid or due to some form of contamination.
Finally, you will learn how to apply popular bioinformatics software tools to reconstruct an evolutionary tree of ebolaviruses and identify the source of the recent Ebola epidemic that caused global headlines.
Who is this class for: This course is primarily aimed at undergraduate-level learners in computer science, biology, or a related field who are interested in learning about how the intersection of these two disciplines represents an important frontier in modern science.
Introduction to Evolutionary Tree Construction
More Algorithms for Constructing Trees from Distance Matrices
Last week, we started to see how evolutionary trees can be constructed from distance matrices. This week, we will encounter additional algorithms for this purpose, including the neighbor-joining algorithm, which has become one of the top-ten most cited papers in all of science since its introduction three decades ago.
Constructing Evolutionary Trees from Characters
Over the last two weeks, we have seen several different algorithms for constructing evolutionary trees from distance matrices.
This week, we will conclude the current chapter by considering what happens if we use properties called "characters" instead of distances. We will also see how to infer the ancestral states of organisms in an evolutionary tree, and consider whether it is possible to define an efficient algorithm for this task.
Did birds evolve from dinosaurs? Over the next two weeks, we will see how we could analyze molecular evidence in support of this theory.
Resolving the T. rex Peptides Mystery?
Last week, we asked whether it is possible for dinosaur peptides to survive locked inside of a fossil for 65 million years. This week, we will see what this question has to do with statistics; in the process, we will see how a monkey typing out symbols on a typewriter can be used to address it.
Bioinformatics Application Challenge
In this week's Bioinformatics Application Challenge, we will use reconstruct an evolutionary tree of ebolaviruses and use it to determine the origin of the pathogen that caused the recent outbreak in Africa.