## Search

Now showing items 1-10 of 14

#### Replacing cliques by stars in quasi-media graphs

(University of Canterbury, 2002)

For a multi-set ∑ of splits (bipartitions) of a finite set X, we introduce the multi-split graph G(∑). This graph Is a natural extension of the Buneman graph. Indeed, it is shown that several results pertaining to the ...

#### Experimental and theoretical analysis of hybridization

(University of Canterbury, 2006)

We develop new heuristics and
an exact algorithm for calculating the
amount of hybridization between two
rooted binary phylogenetic trees. Calculating
the minimum number of hybridization
events is NP-hard, but essential ...

#### The structure of 3-connected matroids of path width three

(University of Canterbury, 2005)

A 3-connected matroid M is sequential or has path width 3 if its ground set E(M) has a sequential ordering, that is, an ordering (e₁, e₂, ... , ek) such that ({e₁,e₂, .. ,,ek}, {ek+₁,ek+₂, .. ,,en}) is a 3-separation for ...

#### Cyclic permutations and evolutionary trees

(University of Canterbury, 2002)

Given a tree T with leaf set X, there are certain ways of arranging
the elements of X in a circular order so that T can be embedded in the plane
and 'preserve' this ordering. We investigate some new combinatorial ...

#### On approximation of optimizing phylogenetic diversity for cluster systems

(University of Canterbury, 2009)

A basic question in conservation biology is how to maximize future
biodiversity as species face extinction. One way to approach this question
is by measuring the diversity of a set of species in terms of the evolutiona ...

#### Fast computation of compatibility for phylogenies with nested taxa

(University of Canterbury, 2005)

Typically, supertree methods combine a collection of source trees in which just the leaves are labelled by taxa. In such methods the resulting supertree is also leaf-labelled. An underlying assumption in these methods is ...

#### A supertree algorithm for higher taxa

(University of Canterbury, 2003)

Most supertree algorithms combine collections of rooted phylogenetic trees with overlapping leaf sets into a single rooted phylogenetic tree (for example, see [1, 4, 6, 7]). Implicit in all of these algorithms is that the ...

#### Exposing 3-separations in 3-connected matroids.

(2009)

Let 𝑀 be a 3-connected matroid other than a wheel or
a whirl. In the next paper in this series, we prove that there is an
element whose deletion from 𝑀 or 𝑀∗ is 3-connected and whose only 3-
separations are equivalent ...

#### Optimizing phylogenetic diversity under constraints

(University of Canterbury, 2006)

Phylogenetic diversity (PD) is a measure of the extent to which different subsets of taxa span an evolutionary tree, and provides a quantitative tool for studying biodiversity conservation. Recently, it was shown that the ...

#### Computing the hybridization number is fixed-parameter tractable

(University of Canterbury, 2006)

Reticulation processes in evolution mean that the ancestral history of certain groups of present-day species is non-tree-like. These processes include hybridization, lateral gene transfer, and recombination. Despite the ...