R: Species Tree Estimation

speciesTree {ape} | R Documentation

## Species Tree Estimation

### Description

This function calculates the species tree from a set of gene trees.

### Usage

    speciesTree(x, FUN = min)

### Arguments

`x` | a list of trees, e.g., an object of class `"multiPhylo"`.
`FUN` | a function used to compute the divergence times of each pair of tips.

### Details

For all trees in `x`, the divergence time of each pair of tips is calculated: these are then ‘summarized’ with `FUN` to build a new distance matrix used to calculate the species tree with a single-linkage hierarchical clustering. The default for `FUN` computes the maximum tree (maxtree) of Liu et al. (2010). Using `FUN = mean` gives the shallowest divergence tree of Maddison and Knowles (2006).

### Value

an object of class `"phylo"`.

### Author(s)

Emmanuel Paradis

### References

Liu, L., Yu, L. and Pearl, D. K. (2010) Maximum tree: a consistent estimator of the species tree. Journal of Mathematical Biology, 60, 95–106.

Maddison, W. P. and Knowles, L. L. (2006) Inferring phylogeny despite incomplete lineage sorting. Systematic Biology, 55, 21–30.

### Examples

    ### example in Liu et al. (2010):
    tr1 <- read.tree(text = "(((B:0.05,C:0.05):0.01,D:0.06):0.04,A:0.1);")
    tr2 <- read.tree(text = "(((A:0.07,C:0.07):0.02,D:0.09):0.03,B:0.12);")
    TR <- c(tr1, tr2)
    TSmax <- speciesTree(TR) # MAXTREE
    TSsha <- speciesTree(TR, mean) # shallowest divergence

    layout(matrix(1:4, 1))
    ## playing with 'x.lim' is not so complicated
    ## but this will be improved someday
    plot(tr1, "c", d = "u", y.lim = c(-0.07, 0.1), font = 1)
    axisPhylo(4); title("Gene tree 1")
    plot(tr2, "c", d = "u", y.lim = c(-0.05, 0.12), font = 1)
    axisPhylo(4); title("Gene tree 2")
    plot(TSmax, "c", d = "u", y.lim = c(-0.1, 0.07), font = 1)
    axisPhylo(4); title("Species tree inferred\nby MAXTREE")
    plot(TSsha, "c", d = "u", y.lim = c(0, 0.17), font = 1)
    axisPhylo(4); title("Species tree inferred\nby Shallowest Divergence")

[Package ape version 4.1 Index]