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Published on: January 29, 2020
Developmental processes underlying the evolution of a derived foot morphology in salamanders
1Museum of Vertebrate Zoology and Department of Integrative Biology, University of California, Berkeley, CA 94720-3160, USA. mj279@cam.ac.uk
Summary
Tropical salamanders repeatedly evolved webbed feet through pedomorphosis, a developmental change. This trait evolved even without a clear adaptive advantage, facilitated by developmental correlations.
Area of Science:
- Evolutionary biology
- Developmental biology
- Amphibian morphology
Background:
- Homoplastic traits, like interdigital webbing, repeatedly evolve in tropical salamanders (bolitoglossines).
- Few morphological traits reliably distinguish lineages within this diverse amphibian clade.
- Understanding the mechanisms behind homoplastic evolution is crucial for amphibian phylogeny.
Purpose of the Study:
- To investigate the selective and developmental processes driving the homoplastic evolution of interdigital webbing in bolitoglossine salamanders.
- To determine if pedomorphosis underlies the repeated evolution of foot morphology.
- To explore the role of developmental correlations in facilitating trait evolution.
Main Methods:
- Comparative analysis of foot morphology across bolitoglossine species.
- Investigation of developmental pathways, specifically focusing on pedomorphosis.
- Assessment of selective pressures acting on foot morphology.
Main Results:
- Pedomorphosis, a developmental change, generates the webbed foot morphology in these salamanders.
- Pedomorphosis influences multiple morphological traits, creating developmental correlations.
- These trait correlations are conserved across most species, promoting repeated evolution.
- Adaptive significance for foot morphology was found in only one species.
Conclusions:
- The repeated evolution of interdigital webbing in tropical salamanders is driven by pedomorphic developmental changes.
- Developmental correlations among traits, established by pedomorphosis, facilitate the recurrent evolution of morphology.
- Interdigital webbing evolves frequently, even in the absence of direct selective advantage, highlighting the power of developmental processes in shaping evolution.
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