Mammalian forelimb evolution is driven by uneven proximal-to-distal morphological diversity
- Muséum National d'Histoire Naturelle, France
- Naturhistorisches Museum Bern, Switzerland
- Université Claude Bernard Lyon 1, CNRS, ENTPE, UMR 5023, France
- University of Oxford, United Kingdom
Abstract
Vertebrate limb morphology often reflects the environment due to variation in locomotor requirements. However, proximal and distal limb segments may evolve differently from one another, reflecting an anatomical gradient of functional specialization that has been suggested to be impacted by the timing of development. Here we explore whether the temporal sequence of bone condensation predicts variation in the capacity of evolution to generate morphological diversity in proximal and distal forelimb segments across more than 600 species of mammals. Distal elements not only exhibit greater shape diversity, but also show stronger within-element integration and, on average, faster evolutionary responses than intermediate and upper limb segments. Results are consistent with the hypothesis that late developing distal bones display greater morphological variation than more proximal limb elements. However, the higher integration observed within the autopod deviates from such developmental predictions, suggesting that functional specialization plays an important role in driving within-element covariation. Proximal and distal limb segments also show different macroevolutionary patterns, albeit not showing a perfect proximo-distal gradient. The high disparity of the mammalian autopod, reported here, is consistent with the higher potential of development to generate variation in more distal limb structures, as well as functional specialization of the distal elements.
Data availability
Morphometric data and R codes are available on Dryad (DOI: 10.5061/dryad.0cfxpnw6h)
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Input data from: Mammalian forelimb evolution is driven by uneven proximal-to-distal morphological diversityDryad Digital Repository, doi:10.5061/dryad.0cfxpnw6h.
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Inferring the mammal tree: Species-level sets of phylogenies for questions in ecology, evolution, and conservationDryad Digital Repository, doi:10.5061/dryad.tb03d03.
Article and author information
Author details
Priscila S Rothier
Funding
Conselho Nacional de Desenvolvimento Científico e Tecnológico (204841/2018-6)
- Priscila S Rothier
European Research Council (2015-STG-677774)
- Roger BJ Benson
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2023, Rothier et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Mammalian forelimb evolution is driven by uneven proximal-to-distal morphological diversity
eLife 12:e81492.
https://doi.org/10.7554/eLife.81492
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