Introduction - An Invariant Approach to Statistical Analysis of Shapes - page 12

growth patterns between two species whose phylogenetic relationship
is known. A combination of tools based on EDMA will allow us to deter-
mine differences in immature morphologies, differences in growth pat-
terns, and differences in adult morphologies, providing an understand-
ing of the role of growth pattern in the determination of adult differ-
ences in cranial morphology.
We will also use these data sets to demonstrate the use of EDMA
tools in experiments in evolutionary morphology. Beginning with an
immature individual of either species, we will demonstrate how our
methods can be used to apply an observed growth pattern to that form,
producing a hypothetical morphology. The hypothetical morphology
represents what an immature form would look like if it had followed
the growth trajectory implemented in the experiment. We believe that
these tools may prove powerful in future analyses of phylogenetic rela-
tionships, evolutionary trajectories, and developmental or phylogenet-
ic constraints.
1.3.3 Data set 3: Human craniofacial dysmorphology and growth
This data set consists of landmark coordinate data collected from com-
puted tomography (CT) scans of children diagnosed with isolated sagit-
tal synostosis (Richtsmeier et al., 1998). Sagittal synostosis is the pre-
Figure 1.4a The developing human skull showing isolated bones (frontal (F), parietal
(P), occipital (O)) and sutures that lie between the bones (coronal (C), sagittal (S), lamb-
doid (L)). 1.4b The typical dolichocephalic shape of a skull when the sagittal suture clos-
es prematurely (sagittal synostosis).