The Study of Growth - An Invariant Approach to Statistical Analysis of Shapes - page 232

Linear Distance Growth Difference

Ratio

PMM-ZMS 0.671

IDS-ZMS 0.694

PMM-MXT 0.726

NSL-IDS 0.726

IDS-MXT 0.773

PMM-PNS 0.777

IDS-PNS 0.788

MXT-PNS 0.815

NSL- MXT 0.840

NSL-ZMS 0.847

NSL-PMM 0.854

ZMS-MXT 0.854

NSL-PNS 0.896

IDS-PMM 0.960

ZMS-PNS 0.991

Since all elements of the growth difference matrix are less than 1, we
know that the species represented by the numerator, Cebus apella ,
experiences a smaller magnitude of change during growth in every
facial dimension as compared to Macaca fascicularis . We also observe
that there is a great degree of variability among the elements of the
growth difference matrix indicating that the difference in facial growth
between these two species cannot be adequately defined as a difference
in scale.
Inspection of the growth difference matrix indicates that the mag-
nitude of growth in the two species is similar for the distance between
ZMS and PNS (the ratio approaches 1). In both species, this is a linear
distance that experienced a relatively small degree of change during
growth. Growth from IDS to PMM was moderately low in both species
and the growth difference matrix shows that the magnitude of growth
is similar in the two species.
Looking at the minimal end of the matrix, we note two linear dis-
tances (ZMS to PMM and ZMS to IDS) that experienced a relatively
large degree of growth for each species. The growth difference matrix
underscores the difference in the magnitudes of growth experienced by
each species local to these distances. The distance between PMM and
MXT measures the length of the maxillary alveolus posterior to the
incisors. Increase in length of the alveolus due to growth is far greater
in Macaca fascicularis as indicated by the growth difference matrix.