Re: Mammal competency.

[John Bois <jbois@umd5.umd.edu>]

This is what I said Dalmiro wrote:

 "(Many dinosaur eggs have been found intact, therefore
dinosaur eggs must not have been preyed on significantly.)"

This is what he did write:

"...we have evidence suggesting that dinos didn't have a big problem
with egg predation, the recent oviraptor found had a huge number of
eggs with him, and the brooding colonies of other dinosaurs don't seem
to have an egg shortage."

I was not trying to be tricky in any sense and I believe I paraphrased
accurately.  But I apologize for my incorrect usage.  I thought
putting parentheses around a passage indicated that I was
paraphrasing.  Live and learn.

> What I meant was this: we have found large collections of intact eggs,
> the eggshell fragments we find show no signs of predation.  If
> predation was so intense as you say we should find traces of it in
> every nest, so we can assume that the mega egg predation hadn't
> started yet.

O.K. That's different and a valid argument.  Part of me wants to say
that finding gnaw marks on an egg would be like finding the Holy Grail
of the nonstealthy nest theory.  But what would it prove?  We already
are certain (without direct evidence, I might add) that egg predation
existed.  What would it prove if mammals were shown to be involved?
One egg with gnaw marks does not an extinction make!  And then its
probably unlikely that eggs shells found would show the marks of
entry.  I'm really unsure about this but wouldn't a mammal break open
the egg at the point of the gnaw, thus destroying the gnaw itself.
And then wouldn't it break the egg open leaving egg shells which, for
all intents and purposes WOULD LOOK IDENTICAL TO HATCHED EGGS?????

>  What I gave was a valid objection and I resent your observation,
> particularly because you disconnect it from the point I was trying
> to make.

But it has no connection, in your original at least.  They are two
separate statements which you are only now connecting (validly,
though).  Reading on from your original: "...have an egg shortage.
Finally it will be hard to explain how the nasty mammal egg eaters
managed to eliminate dinos in places like Australia and New Zealand,
The Americas, Europe, Asia and Africa at roughly the same time."

> You haven't shown the flaw in my main argument: any radical change
> in egg-eating habits would have to develop almost simultaneously in
> continents that were separated by then.

I agree that this is a central problem.  And I'm still trying to
resolve it (if it can be resolved).  Does this mean I should not argue
the rest of it.  Perhaps.

> >      I cannot win if this nonsensical line of argument is
> > supported.  Yet the _non sequitur_ is praised by...
> > 
> > STEVEN S. LAZARUS: "Right on!"
> 
> I advise you more caution when quoting, I believe STEVEN S. LAZARUS
> was "praising" all my objection: intact eggs and isolation, and not
> only the "nonsensical" argument you talk about.

He was praising two statements.  One of them (as originally expressed) was 
nonsensical.  If nonsense is supported I cannot win. 

> You cannot "win" if you don't show evidence on egg predation, you must
> support your claims with data. This is sort of a scientific forum and
> any claims and attacks on other people points of view should be backed
> up with references or with work you have done on the subject. If you
> want something more serious than an informal discussion you should
> show us some evidence, a nest with visible signs of predation,
> mammalian toothmarks on eggshells...

.which would prove not much...

> identify the egg predators and show
> how they could drive dinos into extinction without being much affected
> themselves in the process. 
> Saying it was a short event that lasted
> only 50000 years and left no fossil marks leaves your theory
> untestable, it may be true but we will never know.

That's right.  It may be true.  But right now everyone's out looking for 
a hole in the ground as "proof" of the bolide theory.  I don't believe 
this says anything about dinosaurs in particular, i.e., no pattern of 
extinction is suggested by the finding of an impact crater.  

Dalmiro, there is value in the formulation of a theory.  The
non-stealthy nest theory has value because it ties together some
important lines of evidence.  Primarilty these are the current
distribution of species, the most prominent aspect of which is that
there are practically none of the kind of animals that dinosaurs were,
i.e., big, ground-laying beasts.  Is this just a tremendous
coincidence or is there something about the egg layer's life style
that makes it a liability.  My point is a good one: the egg, unless it
is hidden, is a liability to the continued success of its layer's
genes. Did this have an impact for speciation at the K/T.  Maybe yes,
maybe no.  But ideas can give shape and direction to future research.
Without them research is aimless.  And this is good especially in such
an informal setting such as this where the free exchange of ideas is,
it seems to me, a boon.  All the more important, then, to treat its
conventions with respect.  I will take much greater care when quoting.
I'm sorry if I misrepresented you in any way, and I take your comments
to heart.