Data and analysis scripts: Evidence supporting an evolutionary trade-off between material properties and architectural design in Anolis lizard long bones

Toyama, Ken1 ; Tinius, Alexander1; Mahler, Luke1

Published Nov 21, 2023 on Dryad. https://doi.org/10.5061/dryad.9p8cz8wpp

Data files

Nov 21, 2023 version files 70.79 KB

Abstract

In biology, ‘many-to-one mapping’ occurs when multiple morphological forms can meet a particular functional demand. Knowledge of this mapping is crucial for understanding how selection on performance shapes the evolution of morphological diversity. Past research has focused primarily on the potential for geometrically alternative morphological designs to produce equivalent performance outcomes. Here we ask whether the material properties of biological tissues hold similar potential. Through phylogenetic comparative study of Anolis lizards, we show that the architectural design and mineral density of the femur trade off in a many-to-one functional system, yielding a morphospace featuring parallel isolines in size-relative bending strength. Anole femur evolution has largely tracked a narrow band of strength isolines over phylogenetic timescales, suggesting that geometry and mineral content shape the course of macroevolution through compensatory effects on performance. Despite this conserved evolutionary relationship, insular and continental species evolve strong bones differently, likely reflecting underlying ecological differences. Mainland anoles, which exhibit fast-paced life histories, typically have femora with lower mineralization and thinner walls than island species, which exhibit the opposite strategy. Together, our results reveal an overlooked dimension in the relationship between form and function, expanding our understanding of how many-to-one mapping can shape patterns of phenotypic diversity.

README: Data and analysis scripts for the article 'Evidence supporting an evolutionary trade-off between material properties and architectural design in Anolis lizard long bones.'

https://doi.org/10.5061/dryad.9p8cz8wpp

Datasets and R scripts used to reproduce the analyses presented in the paper.

Description of the data and file structure

This package includes three datasets: 'Anolis_males', 'Anolis_females', and 'simulation_data.csv'. The first two are necessary to run the analyses presented in the main text and some from the supplementary materials (as specified in the R script 'Anolis_femur_paper_analyses.R', see below).

DATA-SPECIFIC INFORMATION FOR 'Anolis_males' AND 'Anolis_females':

Number of variables: 11

Number of rows: 126 (Anolis_males), 91 (Anolis_females)

Variable list:
- species: species names compatible with the respective phylogenetic tree ('Anolis_tree_males' or 'Anolis_tree_females').
- loc: main locality of the species: 'M' for mainland and 'I' for islands.
- colec: collection from which specimens were obtained.
- final_rad: the ratio of the inner femur radius (r) and the total\, or outer\, femur radius (R). Higher values represent hollower bones.
- log.BSI: log-transformed values of bone strength index (BSI).
- log.BMD: log-transformed values of bone mineral density (BMD).
- log.CSA: log-transformed values of cross-sectional area (CSA).
- mean.centered.r.R: mean-centered values from the column final_rad.
- mean.centered.log.BSI: mean-centered values from the column log.BSI.
- mean.centered.log.BMD: mean-centered values from the column log.BMD.
- mean.centered.log.CSA: mean-centered values from the column log.CSA.

The third dataset ('simulation_data.csv') is necessary only for the simulation analysis presented in the supplementary materials and in the R script 'test.determinism.R'. it is based only on empirical male data.

DATA-SPECIFIC INFORMATION FOR 'simulation_data.csv':

Number of variables: 10

Number of rows: 125

Variable list:
- species: species names.
- BMD: empirical raw values of bone mineral density (BMD) in g/cm³.
- r/R: empirical raw values of the ratio of the inner femur radius (r) and the total femur radius (R). Higher values represent hollower bones.
- svl: empirical raw values of snout-vent length (SVL) in milimeters.
- SSD: sexual size dimorphism of the species (male svl/female svl).
- loc: main locality of the species: 'M' for mainland and 'I' for islands.
- diameter: empirical raw values of estimated femur diameters in micrometers.
- sma: empirical raw values of estimated second-moment of area (SMA) (see main text for calculations).
- csa: empirical raw values of estimated cross-sectional area (CSA) (see main text for calculations).
- BSI: empirical raw values of estimated bone strength index (BSI) (see main text for calculations).

Three phylogenies are also included: 'Anolis_tree.tre' (considers all species for which data is available), 'Anolis_tree_males' (considers all species for which male data is available), and 'Anolis_tree_females' (considers all species for which female data is available). These are necessary to run the analyses shown in the R script 'Anolis_femur_paper_analyses.R'.

Code/Software

We include two R scripts that can be used to reproduce the results of the paper. 'Anolis_femur_paper_analyses.R' includes most of the analyses from the main text and supplementary materials, as specified in the script. The script 'test.determinism.R' in particular is used to perform a simulation analysis of determinism mentioned in the text and whose results are shown in the supplementary materials.