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Re: Reduced Consensus (Was: Afrotheria revisited)



Mike Taylor wrote-

 >> Would it be possible to get a DIFFERENT well-resolved tree by
 >> excluding one of the other taxa (this is something that time and
 >> computer power could check!)?
 >
 > Yes it would.

Just to be clear -- you're talking here about _a priori_ exclusion,
right?

Yup. Just like the authors excluded Arsinoitherium a priori.

You're asking for a whole phylogeny of placentals in that case. For example, if you include carnivoramorphs, then you have to include 'creodonts'... and so on.

Of course. Tambuci et al. want their analysis to meaningfully support Afrotheria, but how can they expect that when they have a whopping 2 boreoeutherians (3 assuming mesonychids are...)? And they're not even basal members of the clade. Indeed, they're members of boreoeutherian clades that are most convergent with paenungulates.


Is this partly the consequence of low taxon sampling? Would adding more taxa for certain clades help 'firm up' the bootstrap support for some of the clades? In the analysis above, some very speciose clades (like Proboscidea, Perissodactyla, or Artiodactyla) are each represented by only one (fairly basal) taxon.

Very much so. Imagine a theropod analysis of tyrannosauroids that threw in an abelisaurid and a carcharodontosaurid without bothering with basal ceratosaurs or carnosaurs. Then add in Megalosaurus as the outgroup because it's a fairly plesiomorphic "Carnosauria" incertae sedis. And analyze the mix with 10 characters, but only from the maxilla and femur. That approaches the futility of Tambuci et al.'s matrix. It's great somebody's finally trying to figure out where everything goes, but it needs a TON of work.


I have a hard time imagining how mammalogists don't go insane with so many major groups of mammals that have utterly unknown relationships. That never happens with dinosaurs. At worst we have grades of taxa with uncertain branching order ('hypsilophodonts', 'compsognathids/coelurids', 'prosauropods'), unresolved trichtomies (Troodontidae vs. Dromaeosauridae vs. birds) or multiple well-supported conflicting topologies (Alvarezsauridae). But mammalogists have asioryctitheres, leptictids, anagaloids, zhelestids, dinoceratans, xenungulates, astrapotheres, litopterns, notungulates, arctostylopids, etc. etc.. Madness.

Mickey Mortimer