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Re: Darwin's young dead pet from Messel



There is a cladogram, but it's buried in the supplementary material. It includes three genera.

No, this is not a cladogram. "Cladogram" does not mean "phylogenetic hypothesis represented as a branching diagram with thin, straight lines and sharp angles", it means "the outcome of a phylogenetic analysis" -- and no such analysis was done.


The three taxa aren't three genera, they are "Sterpsirrhini" (sic!!!) (those closer to the lemurs than to us), *Darwinius*, and Haplorhini (those closer to us than to the lemurs -- which means that *Darwinius* is a member of it on that tree, not its sister-group, which is by definition Strepsirhini).

What the authors did was to make a list of strepsirhine and haplorhine character states and check if *Darwinius* has them. That's all. The effects that adding this taxon to any data matrix would have were not explored; _there is no data matrix_. The authors created a phylogenetic hypothesis and _did not test it_. Even for PLoS ONE standards, I don't know how to call this other than a failure of peer review.

While I am at it, you can tell that that particular tree is not a cladogram _by just looking at it_. That's because it contains just three taxa. There is only one possible unrooted tree for three taxa, and thus only one possible rooted tree for three taxa if one of them is the outgroup. A phylogenetic analysis is neither necessary nor possible in this trivial case.