DOI: 10.5061/dryad.q83bk3jtd
title: Data from: Correlation of morphology and metabolism of reproductive traits in the genus Phrynocephalus around the Qinghai-Tibetan Plateau

description: The offspring size-number trade-off is a crucial concept in life-history
 theory, offering key insights into animal reproductive strategies. Our
 study examines the relationship between reproductive characteristics,
 morphological traits, and metabolism in Phrynocephalus lizards across 10
 species around the Qinghai-Tibetan Plateau. Reproductive output and
 morphological and metabolic differentiations were analyzed using
 Phylogenetic Generalized Least Squares (PGLS) and phylogenetic ANOVA. The
 results show no significant differences in reproductive traits between
 oviparous and viviparous species. Snout-vent length and standard metabolic
 rate positively correlated with offspring mass, while no correlation was
 found with offspring number. The lack of a trade-off between offspring
 size and number suggests that larger females invest more in offspring mass
 than in offspring number. These were inconsistent with the classic
 prediction that females give priority to adjusting the number rather than
 the size of their offspring, enabling us to understand the evolution of
 the reproductive strategy in reptiles.
description: <strong>Data collection</strong>
 The morphological variables include snout-vent length (SVL), head
 length (HL), abdomen length (AL), head width (HW), snout length (SL),
 snout width (SW), fore-limb length (FLL), and hind-limb length (HLL). HL,
 HW, SL, SW, FLL, and HLL refer to the length of protruding parts of the
 body. To minimize experimental errors, we used the same caliper with an
 accuracy of 0.01 mm for measurements and had the same experimenter perform
 the operations and readings of the data.
 <strong>Phylogenetic analysis</strong>
 Based on previous studies and our field work in recent years, we
 compiled 10 published mtDNA cytochrome <em>b</em> (cyt
 <em>b</em>) genes (GenBank IDs AY053901, AY053906, AY053915,
 AY053936, AY053946, AY053967, AY053976, AY053991, KF691627, KF691632). To
 construct a phylogeny for <em>Phrynocephalus</em> clades, we
 used MEGA-XI (Tamura et al., 2021) to align selected mtDNA cyt
 <em>b</em> genes with one gene from the
 outgroup <em>Paralaudakia lehmanni</em> (GenBank ID KF691618).
 Phylogenetic trees were constructed separately by using maximum likelihood
 (ML), implemented in PhyloSuite v1.2.1 (Figure 2; Zhang et al.,
 2020). <strong>Statistical
 analysis</strong> All statistical analyses were
 performed with R 4.3.1 (R Development Core Team, 2023). Phylogenetic
 generalized least squares (PGLS) regression and phylogenetic analysis of
 variance (phyANOVA) were conducted using CAPER 1.0.3 (Orme <em>et
 al.</em>, 2023) and geomorph 4.0.7.99(Baken <em>et
 al.</em>, 2021) to analyze the correlations between phenotypic
 traits, metabolism, and reproductive traits. We standardized all
 phenotypic data by dividing each trait by snout-vent length (SVL) to
 remove the influence of individual size. To mitigate collinearity in
 phenotypic data, PCA was conducted on the morphological traits related to
 head size and limb size. Separate principal components were extracted to
 represent head size and limb size. PGLS was conducted to account for the
 nonindependence of data due to the shared evolutionary history among
 species. The strength of phylogenetic signal in phenotypic traits was
 indicated by Pagel’s (1999) lambda (λ). If λ = 0, it suggests no
 significant correlation with phylogeny; if 0 &lt; λ &lt; 1, it
 indicates some degree of correlation with phylogeny; if λ = 1, it
 signifies a strong association with phylogeny.
description: # Data from: Correlation of morphology and metabolism of reproductive
 traits in the genus Phrynocephalus around the Qinghai-Tibetan Plateau
 [https://doi.org/10.5061/dryad.q83bk3jtd](https://doi.org/10.5061/dryad.q83bk3jtd) ## Description of the data and file structure ### Files and variables #### File: 11species.tre Description: The phylogeny of the 11 species of lizards obtained from Maximum Likelihood analysis based on mtDNA cyt *b* gene. Numbers on each node of the tree are the posterior probability (above the branch) and the divergence time (millions of years ago, ma). #### File: phrydatarevised.txt Description: This data file provides *Phrynocephalus* species data used for PGLS (Phylogenetic Generalized Least Squares) analysis, including morphology, metabolism, and reproductive traits. #### File: phrydata_Phenfixrevised.csv Description: This data file contains morphological data for all *Phrynocephalus* species. And head size and limb size data were subjected to phyPCA (*P*hylogenetic principal components analysis). The separate principal components were extracted to represent head size and limb size. The morphological variables include snout-vent length (SVL,mm), head length (HL,mm), abdomen length (AL,mm), head width (HW,mm), snout length (SL,mm), snout width (SW,mm), fore-limb length (FLL,mm), hind-limb length (HLL,mm), tail length(TL, cm). HL, HW, SL, SW, FLL and HLL refer to the length of protruding parts of the body. The abbreviations RAL, RHL,RHW means relative AL (abdomen length), relative HL (head length) and relative HW (head width). These relative indices, along with others the same format, are calculated by dividing the original trait (AL, HL, HW, etc.) by SVL (Snout-Vent Length). ## Code/software #### File: R_code_revised2025.R This code implements PGLS and phyANOVA to analyze correlation of morphology and metabolism of reproductive traits. #### File: phylpca.R This code contains the phyPCA used for conducting on the morphological traits related to head size and limb size.