Data from: Foraging mode constrains the evolution of cephalic horns in lizards and snakes
Data files
Nov 07, 2023 version files 75.59 KB
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1_dataset.csv
73.92 KB
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README.md
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Abstract
A phylogenetically diverse minority of snake and lizard species exhibit rostral and ocular appendages that substantially modify the shape of their heads. These cephalic horns have evolved multiple times in diverse squamate lineages, enabling comparative tests of hypotheses on the benefits and costs of these distinctive traits. Here, we demonstrate correlated evolution between the occurrence of horns and foraging mode. We argue that although horns may be beneficial for various functions (e.g., camouflage, defence) in animals that move infrequently, they make active foragers more conspicuous to prey and predators, and hence are maladaptive. We therefore expected horns to be more common in species that ambush prey (entailing low movement rates) rather than in actively searching (frequently moving) species. Consistent with that hypothesis, our phylogenetic comparative analysis of published data on 1,939 species reveals that cephalic horns occur almost exclusively in sit-and-wait predators. This finding underlines how foraging mode constrains the morphology of squamates and provides a compelling starting point for similar studies in other animal groups.
README: Foraging mode constrains the evolution of cephalic horns in lizards and snakes
https://doi.org/10.5061/dryad.fqz612jzm
This dataset contains the raw data and R codes to replicate our analyses.
Description of the data and file structure
1_dataset.csv: comma separated version of the original dataset (Table S1 – Electronic Supplementary Material), without references. To be used in the analyses with the R codes. This .csv file includes the following data:
- Column ‘species’: scientific name
- Column ‘taxon’: taxon (snake or lizard)
- Column ‘forag_cat’: foraging mode as categorical variable (sit-and-wait = SW; active foraging = AF)
- Column ‘forag_bin’: foraging mode as binomial variable (sit-and-wait = 1; active foraging = 0)
- Column ‘horn_cat’: horn presence as categorical variable (horned = HR; hornless = HL)
- Column ‘horn_bin’: horn presence as binomial variable (horned = 1; hornless = 0)
2_codes.R: codes with step-by-step comments to replicate the analyses we ran and to also plot the elements of Figure 2 and Figure S1.
Sharing/Access information
Phylogenetic data used in our analyses was derived from the following source: https://doi.org/10.5061/dryad.db005
Code/Software
All our analyses were performed using R software version 4.3.1 (2023-06-16 ucrt) – ‘Beagle Scouts’ on RStudio 2023.06.0 - Build 421.
Information concerning which packages were used, how to load '1_dataset.csv' file and how to retrieve and load the phylogenetic data are available in the codes' comments.