1
Download CLC Sequence Viewer
Transcript
CHAPTER 15. PHYLOGENETIC TREES 151 Note! Dragging in a tree will change it. You are therefore asked if you want to save this tree when the Tree Viewer is closed. You may select part of a Tree by clicking on the nodes that you want to select. Right-click a selected node opens a menu with the following options: • Set root above node (defines the root of the tree to be just above the selected node). • Set root at this node (defines the root of the tree to be at the selected node). • Toggle collapse (collapses or expands the branches below the node). • Change label (allows you to label or to change the existing label of a node). • Change branch label (allows you to change the existing label of a branch). You can also relocate leaves and branches in a tree or change the length. It is possible to modify the text on the unit measurement at the bottom of the tree view by right-clicking the text. In this way you can specify a unit, e.g. "years". Note! To drag branches of a tree, you must first click the node one time, and then click the node again, and this time hold the mouse button. In order to change the representation: • Rearrange leaves and branches by Select a leaf or branch | Move it up and down (Hint: The mouse turns into an arrow pointing up and down) • Change the length of a branch by Select a leaf or branch | Press Ctrl | Move left and right (Hint: The mouse turns into an arrow pointing left and right) Alter the preferences in Side Panel for changing the presentation of the tree. Note! The preferences will not be saved. Viewing a tree in different viewers gives you the opportunity to change into different preferences in all of the viewers. For example if you select the Annotation Layout species for a node then you will only see the change in the specified view. If you now move leaves, the leaves in all views are moved. The options of the right-click pop up menu are changing the tree and therefore they change all views. 15.2 Bioinformatics explained: phylogenetics Phylogenetics describes the taxonomical classification of organisms based on their evolutionary history i.e. their phylogeny. Phylogenetics is therefore an integral part of the science of systematics that aims to establish the phylogeny of organisms based on their characteristics. Furthermore, phylogenetics is central to evolutionary biology as a whole as it is the condensation of the overall paradigm of how life arose and developed on earth.
