Open AccessHead shape allometry and proximate causes of head sexual dimorphism in Podarcis lizards: joining linear and geometric morphometrics
Author(s) -
KALIONTZOPOULOU ANTIGONI,
CARRETERO MIGUEL A.,
LLORENTE GUSTAVO A.
Publication year - 2008
Publication title -
biological journal of the linnean society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.906
H-Index - 112
eISSN - 1095-8312
pISSN - 0024-4066
DOI - 10.1111/j.1095-8312.2007.00921.x
Subject(s) - sexual dimorphism , allometry , biology , morphometrics , zoology , ontogeny , head (geology) , sexual selection , heterochrony , anatomy , evolutionary biology , ecology , paleontology , genetics
Podarcis bocagei and Podarcis carbonelli are two lacertid species endemic to the western Iberian Peninsula, and both show head size and shape sexual dimorphism. We studied immature and adult head sexual dimorphism and analysed ontogenetic trajectories of head traits with body and head size, aiming to shed light on the proximate mechanisms involved. Immatures were much less dimorphic than adults, but geometric morphometric techniques revealed that head shape sexual differences are already present at this stage. Males and females differed in allometry of all head characters with body size, with males showing a disproportionate increase of head size and dimensions. On the other hand, head dimensions and head shape changed with increasing head size following similar trends in both sexes, possibly indicating developmental restrictions. Consequently, adult sexual dimorphism for head characters in these species is the result of both shape differences in the immature stage and hypermetric growth of the head in relation to body size in males. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 93 , 111–124.