New function to add species to a genus in a phylogeny

Recently an R-sig-phylo subscriber made the following request:

"I need to add a list of 230 species in a phylogenetic tree. Is there a logical way to add the species to the root of the genera to which it belongs, in a systematic way, that is, to make a function recognizes the name of the genera to which the species belongs, and so it adds the species to that root?"

I posted a solution to this, but I also thought that other phytools users might face the same problem so I have now automated this in the function add.species.to.genus. This, along with the matrix comparison function skewers, is also in a new minor phytools build (phytools 0.3-73).

The function works by first peeling the genus name out of the species name. It does this by looking for either the underscore character, "_", or a space character, "". It then proceeds to identify the clade containing con-generics in the tree by matching the genus name to the tip labels. Finally, it can either attach the new species to the root node of the most inclusive clade containing congenerics; or it can attach the new species randomly within that clade. In general, the function works best if the input tree is ultrametric. Otherwise, it may return a tree without edge lengths!

Here's a quick demo:

If the user supplies a species name for a genus with only one representative in the tree; a species with no congeners in the tree; or a genus that is non-monophyletic, in each case the function will try to do something rational and return a warning.

That's it.