BM211 Workshop 5: Phylogenetic Trees

Author

Leighton Pritchard and Morgan Feeney

Published

March 19, 2024

Preface to 2023-24 BM211 Workshop 5: Phylogenetic Trees

Welcome to the BM211 (Introduction to Microbiology) workshop on phylogenetic trees, for 2023-24.

This year is the first presentation of the workshop material in this format, and we would be very grateful to hear feedback by email or through the GitHub repository Issues page.

Overview

This workshop asks you to work through some computational exercises to gain some practice visualising and working with phylogenetic trees.

Note

Phylogenetic trees are typically constructed after sequence alignment has been performed. You learned about the fundamentals of (pairwise) sequence alignment in BM214 Workshop 2 - slides, workshop. You may find it useful to refresh your memory about this topic.

Important Note

There is new material in this workshop that is not covered in lectures, and this material is examinable. Please take care to reach the text in the expandable callout boxes, as well as that for the workshop activities, to be sure you have understood the topic and obtain full value from the exercises.

Learning Objectives

By the end of this workshop, students will be able to:

  • explain how a phylogenetic tree represents history and ancestry
  • use iToL to visualise a variety of phylogenetic tree types
  • describe and interpret the topology of a tree
  • generate a phylogenetic tree for a protein sequence and its homologues using UniProt, MUSCLE, and iToL
  • explain the difference between a gene tree and a species tree
  • compare a gene tree with a species tree to interpret evolutionary history

Assessment

The workshop is not formally assessed although, as noted above, all the material contained in the workshop is examinable. We have provided formative exercises to help you measure your progress.

Important

There are four formative exercises in this workshop, and they can be found on the workshop MyPlace page. You should complete these as part of the workshop.