Mullin, S. K., Taylor, P. J. & Pillay, N. 2004. Skull size and ... - Durban

MULLIN_08 13/08/04 12:45 Page 10
Mullin S. K. et al.
FIG. 2. – Plot of the first two canonical variates using the traditional morphometric data. , West African D. rufulus; 〈, D. foxi, π,
Ethiopia and Sudan; , D. i. griseifrons; , Cameroon, Central African Republic, Congo, Democratic Republic of Congo; ⊃, D. i.
longipilosus; σ, East Africa; ∠, D. montanus; , Malawi, Mozambique and Tanzania; τ, D. incomtus from Angola; υ, D. nudipes;
ρ, Botswana and Namibia; ≤, Zambia; , Zimbabwe; θ, Limpopo and Mpumalanga Provinces, South Africa; ϖ, KwaZulu-Natal
Province, South Africa; ÷, D. i. capensis. OTUs (defined in Table 6.1) containing karyotyped individuals are demarcated by the diploid
number. Eleven type specimens are identified: 1-D. i. capensis, 2-D. foxi, 3-D. i. fuscus, 4-D. i. griseifrons, 5-D. incomtus, 6-D. i.
longipilosus, 7-D. montanus, 8-D. i. nigridius, 9-D. nudipes, 10-D. i. palustris, 11-D. rufulus.
led us to test Wright’s (1943) isolation by distance
theory on populations from this country. A
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P R O O F
matrix of Mahalanobis distances between popula-
tions was computed from ventral landmark data
using the program TPS-Small (Rohlf 2000b) and
was compared to a matrix of geographic distances
using NTSYS-pc (Rohlf 1996).
RESULTS
MACRO-SCALE PATTERNS
The data suggest that size rather than shape was
more important in identifying species or species
groups on a large geographic level (Figs 2-4), as
indicated by the strong patterns seen with traditional
morphometric data. The first two axes of the
CVA based on traditional measurements explained
46.34% of the variation compared to 27.62%
and 27.22% in the dorsal and ventral data, respectively.
In addition, the Wilks λ value was higher
for the traditional dataset (Wilks λ =0.001,
p < 0.001, F 169,5764 = 41.83, p < 0.01) than it
was for the both of the geometric morphometric
datasets: dorsal (Wilks λ =0.00000008, p < 0.001,
F 484,8298 = 6.67, p < 0.01) and ventral (Wilks λ
= 0.0003, p < 0.001, F 1444,11502 = 11.56,
p < 0.01). The importance of size in this study was
confirmed when the centroid sizes for both the
dorsal and ventral views were regressed onto the
landmark data. Between the two shape datasets,
the ventral view showed stronger patterns than the
dorsal view and generally confirmed the results
seen using the traditional dataset.
MAMMALIA • 2004 • 68 (2)