[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Dollodon status questioned
Forwarded for Liz Freedman
On Fri, Mar 25, 2011 at 1:36 AM, Jaime Headden <qi_leong@hotmail.com> wrote:
> I wonder if McDonald uses some more substantive reasoning (optimistically,
> I
>assume he does) than in the abstract -- which is, let's face it, an abstract.
>I
>haven't the paper, but will soon.
>
Not really - he runs a PCA on a mere 3 measurements for each specimen
(which would give any statistician a heart attack), and those 3
measurements are all known to vary with the size of the specimen
(i.e., likely ontogenetically). Axis 1 (80% of variance) is probably
based entirely on the size of the specimen, with no real taxonomic
value.
-Liz Freedman