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Re: My apologies, but... physiology revisited



Stan responds to me:

> You lost some of the context: what was claimed is that only four *birds*
> were included in the analysis.

I did not.  Your objection lost all credibility with me when I looked
back at the paper.  I left in your statement including the part that
you were objecting to there being only four *birds*, but couldn't
believe that that would have bothered you if you'd actually looked at
the data.

The fact that you can answer me with suggests that as I said before
you either haven't, or have just plain forgotten:

> Yep, I bet this is 4 birds and 8 mammals - right?

Why do you need to bet?  I highly recommend that you not say anything
else on the subject until you read (or re-read) the paper.

> But even a sample size of 12 is still disturbingly small.  To get
> really good statistics one wants sample sizes of at least 40-50, and
> hundreds is even better.

Have you read the methods to find out how much work went into the
collection of each data point?  Have you looked at how closely the
points fall along their respective regression lines?

> Furthermore, unciritcally lumping mammals and birds in a single
> regression line rather tends to beg the question. It is simply not
> neccessarily the case that mammals and birds fall on the same
> regression line.

This is precisely why I say I expect better of you.  *LOOK* at the
paper.  The birds most certainly do fall on the same regression line.
Showing that was most likely part of the point of graphically
displaying the data.  The authors expected the data to show the trend
they do because they have a functional link between structure and
metabolism.  As I said to Greg, why do *you* propose that the bird
data fall on the same regression line as the mammals?  Alternatively
why are they well above the regression line of the crocodiles and
lizards?

> Well, we don't really know that the samples were random anyhow. If
> there was any selectivity in choosing the organisms to include in
> the study, even an unconsious selectivity, this sort of significance
> could *easily* be a total artifact.

This is a pretty significant charge coming from a person who doesn't
appear to have even read the paper.  I'm planning to look into Guy
Leahy's charge.  Yours IMHO should never have been uttered.  You
disappoint me again.  Note for the crowd: as I said before, I'm
picking on Stan because I think he ought to know better, but I'm also
spending my time on this because I think Stan is representative of a
lot of people who are much happier thinking of dinosaurs as endotherms
a la mammals and birds rather than as anything else.  If you're going
to use a critical eye (which I highly recommend) then use it
everywhere the same.

--
Mickey Rowe     (mrowe@indiana.edu)