-------- Original Message --------
Subject: Visualization of non-allometric shape change in MorphoJ
Date: Tue, 17 Jan 2012 08:24:36 -0500
From: Marko Djurakic <[email protected]>
To: Morphmet <[email protected]>
Dear morphometricians,
I’d like to compare sexual shape dimorphism and its patterns among four
groups after size correction. I have some struggle regarding
visualization of non-allometric shape changes in MorphoJ.
Here is step-by-step procedure that I used in analysis:
My dataset contain four groups (A, B, C and D) and within each of them
there were two sexes (male and female) as subgroups.
1. I did the GPA on the whole dataset.
2. First I was interested in SShD within each group and therefore I
subdivided dataset by “group” factor in preliminaries menu, unchecking
the “separate procrustes fit”, resulting in four new datasets (A, B, C
and D). Each of them contains 2 classifiers (sex and group). Please
consider that group classifier was invariant then.
3. I performed regression analysis pooled by sex in each group
(regression slopes between sexes were homogeneous) – overall four
separate regressions. To visualize shape changes of allometric and
non-allometric component “averaged observation by” option was used in
preliminaries menu. As averaging factor I used “sex” and “group”,
respectively. I did the same averaging procedure *for* each group.
Averaging by sex results: MorphoJ showed predicted and residuals shape
changes for both females and males (4 graphs at all per group)
Averaging by group results: MorphoJ showed predicted and residuals shape
changes for a group (2 graphs per group), but they appeared precisely
the same regarding direction and magnitude of the shape change which was
unusual.
Main objective is to visualize allometric and nonallometric shape change
of each group.
Did I miss some step or it is just a bug in the program MJ? If so, how I
can visualize non-allometric shape change in MJ? I used 1.04a version of
MorphoJ. Additionally, I did the same analysis on other dataset and
results were the same.
--
MarkoĐurakić, PhD student,
University of Novi Sad
Faculty of Sciences
Department of Biology and Ecology
Dositej Obradović Square 2
21 000 Novi Sad
Serbia
e-mail:[email protected]
