Introduction - Geometric Morphometrics for Biologists - page 12

FIGURE 1.10 Removing variation due to differ-

ences in position, scale and orientation. (A) Two origi-
nal configurations; (B) after removing differences in
location; (C) after removing differences in scale; (D) after
removing differences in orientation, leaving only differ-
ences in shape.

(A)

(B)

(C)

(D)

that are attributable to differences in location, scale and orientation leaves only differences
in shape. These operations and their consequences are illustrated in Figure 1.10 .In
Figure 1.10A , there are two configurations, side by side. This difference in location has no
bearing on their shape difference so, in Figure 1.10B , both have been translated to the
same location. The two configurations still differ in scale, which also has no bearing on
their shape difference so, in Figure 1.10C , they are converted to the same scale. The two
configurations still differ in orientation (their long axes are about 45 apart). That, too, has
no bearing on their shape differences so, in Figure 1.10D , they are rotated to an alignment
that leaves shape as the only difference between them. After removing all the differences