Morphological data
These data are derived from 151 specimens from our recent fieldworks and
Herpetological Museum of the Chengdu Institute of Biology, CAS. The
sample size varied between 8 and 42 specimens per clade (only male
adults included), with a mean of 25 individuals per clade. The
morphological variables including: snout–vent length (SVL), head length
(HL), head width (HW), snout length (SL); inter-nasal space (INS), width
of upper eyelid (UEW), inter-orbital space (IOS), diameter of eye (ED),
length of lower arm and hand (LAHL), diameter of lower arm (LAD),
hind-limb length (HLL), tibia length (TL), tibia width (TW), length of
foot and tarsus (TFL) and foot length (FL), named system of
morphological variables following
Fei
et al. (2005). Males within S. boulengeri predominant
outstandingly in two pairs of keratinized spine patches on the chests
and fingers of males and in variation adult body size and diameter of
lower arm between them
(Fu
et al. 2007, Chen et al. 2009). In data analysis, we removed females for
their insufficient quantity. Prior to all statistical analyses, the
variables were log-transformed to better meet the requirements of
normality and homogeneity
(Rabosky
and Adams 2012).
PCMs
and trait correlative analyses
Biologists have long recognized that closely related species are
generally more similar to one another than they are to more distantly
related, which is often termed phylogenetic conservatism (Martin and
Hansen 1997). Phylogenetic signal can be thought of as the degree to
which similarity in trait values between species can be predicted upon
their relatedness (Harvey and Rambaut 2000). If there is phylogenetic
signal in the data, then PCMs are necessary for robust statistical
analyses of trait correlations. To address the relationships between
morphology and climate variables caused by niche evolution, we used PGLS
(Grafen 1989,
Martins
and Hansen 1997).