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Re: Hanson 2006, Mortimer, Baeker response
> Martin, I limit my argument to my cladogram of pterosaurs. I say nothing about
> anyone else's cladogram of dinos. You said: "if we look at a cladogram
> as many species as your probably does, the number of unresolved points is
> huge." I
> guess you meant in _any_ cladogram with many species there are many unresolved
> points. I meant, despite the large number of species in _my_ cladogram the
> of unresolved points is zero.
And the fact that this is the only cladogram in existence of this size
that is completely resolved should not make me suspicious?
Read our mails again - it was you who claimed that dinosaur
cladograms were as well resolved as your ptero cladogram.
> > To be honest, I am not much in pterosaurs and I couldn't care less how
> > their tree will be resolved. I do not argue against certain cladogram,
> > but against what seems to me bad science, and that's were I get
> > hot-headed.
> I appreciate your candor. If I were to suspect bad science in a cladogram, I
> as I was able to do with Hanson's cladogram dissect it piece by piece. If I
> not dissect it at face value, I would have asked for the data in order to try
> understand the patterns and perhaps come to a new appreciation of a new way of
> looking at things. I note that you have not attempted to dissect my cladogram
> by piece. I'm not sure that you have even seen my cladogram. And if not, you
> railing against what?
Against circularity in arguments.
BTW, I did spent some time with your photographs and scans to see
whether your photoshop-technique might not be right.
To dissect your cladogram, I would need:
* lots of time
*access to the fossils
* your cladogram
* probably more knowledge of pterosaur anatomy than I have.
None of which I do have. There are others, though, who do.
What I rail against is the argument that your
cladogram is correct (in whatever sense you understand this, as you do
not like the word "prove") because it has only 1 MPT and that the data
you plug into it (photoshop scans, tiny adults) are correct because
they end up in producing this fantastic cladogram.
> > No, but IMHO the evidence for 2+2=4 is slightly better than that for
> > all those tiny pteros.
> And yet, twenty years from now, after everyone accepts tiny pteros as adults,
> children will have no problem understanding this form of evolution. After all
> falls into a well known pattern: tiny cynodonts became mammals. Tiny dinosaurs
> became birds. Tiny amphibians became reptiles. Tiny archosaurs became
> dinosaurs. It
> happens all the time.
I would not have problems understanding this form of evolution - I
just don't accept what you call evidence for it.
> > > Too many times? Can you name two times?
> > I can name as many as you like: Astrology, mesmerism, shamanism,
> > vodoo, UFOs, ..
> > All these pseudosciences claim to explain it all (And most of them
> > claim to be scienctifically provable). So if you find a theory that
> > does likewise, make sure that you don't enter pseudoscience.
> Ahh, I was limiting my thinking to the eu-sciences, like plate-tectonics,
> universe, evolution. Interesting.
Indeed - you don't even consider that you may be wrong, it seems. BTW,
plate tectonics, when it was first suggested, was rejected because
although there was evidence for it from many sources, no-one was able
to propose a mechanism for it. So, at that time, it was reasonable to
reject it until further evidence came along. Wegner, IIRC, tried to
argue with centrifugal forces, but it was easy to show that this was
> > But, surprisingly, you argue all of the time that your cladogram is
> > better than others because it has a better resolution (1 MPT). (See
> > statement above: "My cladogram solves more problems than any other" -
> > may be true, but does not make it right.) I'll just repeat it one
> > final time and then I'll rest my case: The *outcome* of a
> > cladogram cannot prove it valid or invalid, it is the *input* that has
> > to be scrutinized.
> I'll say once again, when you repeat the word "prove" it sounds like you're
> listening. At all costs, avoid the word "prove." And taxon exclusion leads to
> problems in cladistic analysis, as I can "demonstrate" over and over in many
> clades, from bat ancestry to turtle ancestry. You're trying to exclude taxa.
No, I'm excluding juveniles because they differ from adults in more
than just their phylogenetic position.
> > As my philosophy teacher told us (one of the few useful things I got
> > from there): From a wrong premise, you can conclude anything, even a
> > truth.
> And as history will tell you, attitudes and prejudices color thinking.
So does the strong believe of being the next Galilei, Darwin or whatever.
> > > > But to find out whether it is a juvenile or not, you cannot look at
> > > > cladograms - look at the proposed juvenile's bones and check whether
> > > > they are fully ossified, remodeled, whether sutures have closed etc.
> > >
> > > I have and they're adult-like.
> > Wow - I did not know that anyone so far was able to section these
> > bones. Are they fibrolamellar? How large is the osteon density?
> So there we are: you just told me that the bone structure has not been
> So, why do you say No. 9 is a juvenile based on bone structure?
I do not - it is you who has to prove they are not, because *you* are
making the extraordinary claims. And you did claim that the bone
structure is adult-like. I claimed that the fact that entering them as
adults in a cladogram and getting a nice result is no evidence of
their being adults.
> > Impossible is nothing (Adidas), but highly improbable. ;-)
> > So, they are *not* fully ossified in direct contradiction to your
> > statement in the previous paragraph?
> I'm saying fully ossified or not, tiny pteros can have sex with each other and
> produce eggs.
Don't doubt that, I just doubt they could fly very well with
> > And yes, it is *very* improbable that they are nor fully
> > ossified. Wing bones in animals are selected for stiffness, mainly
> > (and toughness, next). Stiffness is governed by mineral content. An
> > unossified flyer would have lots of trouble with torsion and bending
> > in the wings - can't see how selection would not manage to ossify
> > earlier in individual history in this case.
> And yet, some baby birds fly immediately upon hatching. And Dr. Unwin
> suggests the
> same for pterosaurs. So your argument has been falsified.
Do these have un-ossified bones? I doubt it - if I'm wrong, it would
probably be extremely interesting to understand how they can manage
with low-stiffness bones. (BTW, which birds fly directly after hatching?)
Priv.-Doz. Dr. Martin BÃker
Institut fÃr Werkstoffe
Langer Kamp 8