Re: [dinosaur] Party like it's 1758!

[Paul P <turtlecroc@yahoo.com>]

A few replies to the recent replies....

> > ancestor of A and B" becomes a mess if A or B turns out not to belong to 
> > that clade.
> I thought, by definition, that A and B had to be part of the clade.

Sure, by definition, but what if A or B was misinterpreted and actually belongs 
to some other group entirely..? That screws up the definition of the new A+B 
group. Nor can reviewers be expected to catch everything. 


> In the research on Mesozoic dinosaurs, and much else of vertebrate 
> paleontology, it is usually the genus rank that is applied to the smallest 
> recognizable clades, and species names are an afterthought added to honor 
> colleagues or make clever puns with.

Many taxa (species) do have multiple individuals referred to them, so it's an 
over-generalization to say dinosaur palaeontology treats genera as species. 
There is a trend toward splitting these days, with some genera being separated 
into multiple species. One reason there are so many monospecific genera is that 
species differences in many cases are minor and hence not recognized. Does that 
make sense?

Over time, the new-taxa curve will level off while the 
total-number-of-specimens curve continues to climb at a more or less constant 
rate. A hundred years from now, I think the vast majority of dinosaur species 
will have many specimens referred to them, hundreds for some.

Btw, I'd be curious to know some of those clever specific puns. Some species 
names are annoying, yes (as well as some genus names), but most are legit. 


> There's actually some foreseeable final design that we're approaching as we 
> learn more about the tree of life.

Hmm, risky choice of words there. Anyway, it's more a bush of life than a tree. 
Hybridization, introgression, and related phenomena are much more common than 
once thought, with interbreeding between distinct species, and even distinct 
genera, not uncommon. Yeah I know, if they can interbreed, then they're not 
distinct species (much less genera). Except that they are, by some major 
species concepts. At a minimum, they are distinct, separately-evolving 
populations and need to be accounted for in a phylogeny. Many populations that 
we thought were single species are turning out to have multiple 
genetically-distinct subpopulations. Dolphins, elephants, caimans, you name it. 
This means species or incipient species.

    Paul P.