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Vol. 54, 2015
Geometric morphometric analysis of the head of Microlophus atacamensis (Tropiduridae) in a
latitudinal gradient
Soledad Ibáñez1*,
Marcela A Vidal1, Juan Carlos Ortiz2 and Fernando
Torres-Pérez3
1Departamento de Ciencias Básicas, Facultad de Ciencias, Universidad del Bío-Bío, Casilla 447, 4051381 Chillán, Chile
2Departamento de Zoología, Facultad de Ciencias
naturales y Oceanográficas, Universidad de Concepción, Casilla 160-C,
Concepción, Chile
3Instituto de Biología, P. Universidad Católica de Valparaíso, Av. Universidad 330, Campus Curauma, Valparaíso, Chile
Abstract
Background: Clinal variation is
defined as gradual variation in a character associated with geographic
distance among sites. Microlophus
atacamensis is a medium
large lizard species which inhabits the intertidal zone of northern
Chile, distributed from Antofagasta (23° 39′ S) to Arrayán, La Serena
(29° 41′ S) in a gradient which could show clinal variation. Geometric
morphometrics analyzes differences in shape independent of size;
information about shape allows a more complete biological
interpretation than information on morphological variation. This study
evaluated clinal variation in the head shape of M. atacamensis from five localities
(Antofagasta, Paposo, Pan de Azúcar, Caldera, and Tres Playitas) using
dorsal and lateral views, comparing form variation with latitudinal
distribution. The heads of adults collected were photographed in
lateral and dorsal views.
Results: The analysis did not find significant
differences in form among the five localities, in contrast to the
proposal of earlier studies, and no differences were recorded between
the sexes. Possible reasons why these populations are not
differentiated in the latitudinal gradient are discussed.
Conclusions: Our results show that
there are no differences between the studied, among the explanations
are that populations of this species are subjected to similar
environments that promote convergence of the structures analyzed.
Key words: Atacama Desert; Lizard; Shape
morphometrics; Head.
*Correspondence: E-mail: soledadibanez7@gmail.com
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