* along with Jalview. If not, see <http://www.gnu.org/licenses/>.
* The Jalview Authors are detailed in the 'AUTHORS' file.
-->
-<head><title>Tree Calculation</title></head>
+<head>
+<title>Tree Calculation</title>
+</head>
<body>
-<p><strong>Calculation of trees from alignments</strong></p>
-<p>Trees are calculated on either the complete alignment, or just the
-currently selected group of sequences, using the functions in the
-<strong>Calculate→Calculate tree</strong> submenu.
-Once calculated, trees are displayed in a new <a
-href="../calculations/treeviewer.html">tree viewing window</a>. There are
-four different calculations, using one of two distance measures and
-constructing the tree from one of two algorithms :
-</p>
-<p><strong>Distance Measures</strong></p>
-<p>Trees are calculated on the basis of a measure of similarity
-between each pair of sequences in the alignment :
-
-
+ <p>
+ <strong>Calculation of trees from alignments</strong>
+ </p>
+ <p>
+ Trees are calculated on either the complete alignment, or just the
+ currently selected group of sequences, using the functions in the <strong>Calculate→Calculate
+ tree</strong> submenu. Once calculated, trees are displayed in a new <a
+ href="../calculations/treeviewer.html">tree viewing
+ window</a>. There are four different calculations, using one of two
+ distance measures and constructing the tree from one of two
+ algorithms :
+ </p>
+ <p>
+ <strong>Distance Measures</strong>
+ </p>
+ <p>Trees are calculated on the basis of a measure of similarity
+ between each pair of sequences in the alignment :
<ul>
<li><strong>PID</strong><br>The percentage identity
between the two sequences at each aligned position.
residues)'.</em>
</li>
</ul>
- <li><strong>BLOSUM62, PAM250, DNA</strong><br/>These
- options use one of the available substitution matrices to compute
- a sum of scores for the residue pairs at each aligned position.
- <ul><li>For details about each model, see the
- <a href="scorematrices.html">list of built-in score matrices</a>.
+ <li><strong>BLOSUM62, PAM250, DNA</strong><br />These options
+ use one of the available substitution matrices to compute a sum of
+ scores for the residue pairs at each aligned position.
+ <ul>
+ <li>For details about each model, see the <a
+ href="scorematrices.html">list of built-in score
+ matrices</a>.
</li>
- </ul></li>
+ </ul></li>
<li><strong>Sequence Feature Similarity</strong><br>Trees
are constructed from a distance matrix formed from Jaccard
distances between sequence features observed at each column of the
same type will be grouped together in trees computed with this
metric. <em>This measure was introduced in Jalview 2.9</em></li>
</ul>
- <p><strong>Tree Construction Methods</strong></p>
-<p>Jalview currently supports two kinds of agglomerative clustering
-methods. These are not intended to substitute for rigorous
-phylogenetic tree construction, and may fail on very large alignments.
-<ul>
-<li><strong>UPGMA tree</strong><br>
- UPGMA stands for Unweighted Pair-Group Method using Arithmetic
- averages. Clusters are iteratively formed and extended by finding a
- non-member sequence with the lowest average dissimilarity over the
- cluster members.
-<p></p>
-</li>
-<li><strong>Neighbour Joining tree</strong><br>
- First described in 1987 by Saitou and Nei, this method applies a
- greedy algorithm to find the tree with the shortest branch
- lengths.<br>
- This method, as implemented in Jalview, is considerably more
- expensive than UPGMA.
-</li>
-</ul>
-<p>A newly calculated tree will be displayed in a new <a
-href="../calculations/treeviewer.html">tree viewing window</a>. In
-addition, a new entry with the same tree viewer window name will be added in the Sort
-menu so that the alignment can be reordered to reflect the ordering of
-the leafs of the tree. If the tree was calculated on a selected region
-of the alignment, then the title of the tree view will reflect this.</p>
+ <p>
+ <strong>Tree Construction Methods</strong>
+ </p>
+ <p>Jalview currently supports two kinds of agglomerative
+ clustering methods. These are not intended to substitute for
+ rigorous phylogenetic tree construction, and may fail on very large
+ alignments.
+ <ul>
+ <li><strong>UPGMA tree</strong><br> UPGMA stands for
+ Unweighted Pair-Group Method using Arithmetic averages. Clusters
+ are iteratively formed and extended by finding a non-member
+ sequence with the lowest average dissimilarity over the cluster
+ members.
+ <p></p></li>
+ <li><strong>Neighbour Joining tree</strong><br> First
+ described in 1987 by Saitou and Nei, this method applies a greedy
+ algorithm to find the tree with the shortest branch lengths.<br>
+ This method, as implemented in Jalview, is considerably more
+ expensive than UPGMA.</li>
+ </ul>
+ <p>
+ A newly calculated tree will be displayed in a new <a
+ href="../calculations/treeviewer.html">tree viewing
+ window</a>. In addition, a new entry with the same tree viewer window
+ name will be added in the Sort menu so that the alignment can be
+ reordered to reflect the ordering of the leafs of the tree. If the
+ tree was calculated on a selected region of the alignment, then the
+ title of the tree view will reflect this.
+ </p>
-<p><strong>External Sources for Phylogenetic Trees</strong></p>
- <p>A number of programs exist for the reliable construction of
- phylogenetic trees, which can cope with large numbers of sequences,
- use better distance methods and can perform bootstrapping. Jalview
- can read <a
- href="http://evolution.genetics.washington.edu/phylip/newick_doc.html">Newick</a>
- format tree files using the 'Load Associated Tree' entry of the
- alignment's File menu. Sequences in the alignment will be
- automatically associated to nodes in the tree, by matching Sequence
- IDs to the tree's leaf names.
+ <p>
+ <strong>External Sources for Phylogenetic Trees</strong>
+ </p>
+ <p>
+ A number of programs exist for the reliable construction of
+ phylogenetic trees, which can cope with large numbers of sequences,
+ use better distance methods and can perform bootstrapping. Jalview
+ can read <a
+ href="http://evolution.genetics.washington.edu/phylip/newick_doc.html">Newick</a>
+ format tree files using the 'Load Associated Tree' entry of the
+ alignment's File menu. Sequences in the alignment will be
+ automatically associated to nodes in the tree, by matching Sequence
+ IDs to the tree's leaf names.
</p>