Gerade angezeigt 1 - 2 von 2
  • Some of the metrics are blocked by your 
    Item-typ:Veröffentlichung,
    Ecomorphology of the Locomotor Apparatus in the Genus Cyrtodactylus (Gekkota, Squamata)
    Adaptive radiations garner considerable interest from evolutionary biologists. Lizard radiations diversifying along structural niche space often exhibit distinct changes in body and limb proportions. One prediction is that terrestrial species inhabiting open habitats will have relatively longer hindlimbs, associated with faster running speeds, while scansorial species will have relatively shorter limbs to keep the centre of mass closer to the substratum. Alternatively, terrestrial species in densely vegetated habitats could benefit from relatively shorter limbs to prevent entanglement with more frequently encountered obstacles, whereas scansorial species could benefit from longer limbs promoting greater limb spans and static stability. Cyrtodactylus, an ecologically diverse gekkonid genus, includes numerous specialists with narrow structural niches, but the degree of morphological diversification exhibited by these specialists is largely unknown. We investigated associations between locomotor morphology and structural microhabitat use in Cyrtodactylus to test if either of the opposing predictions can be corroborated for this radiation. We measured body length and relative limb dimensions of 87 species, covering multiple independent transitions among structural microhabitat preferences. Using these data, we reconstructed the phylomorphospace and tested for associations between structural microhabitat niche and limb morphology. We found strong separation between structural niche groups in accordance with the second hypothesis, although overlap is evident among functionally related niches such as those of granite and karst specialists.
    Wissenschaftlicher Artikel
    Band:
    Heft:
      51
  • Some of the metrics are blocked by your 
    Item-typ:Veröffentlichung,
    Ecologically‐related variation of digit morphology in Cyrtodactylus (Gekkota, Squamata) reveals repeated origins of incipient adhesive toepads
    Exploitation of different locomotor substrates in different ecological niches has driven the evolution of specialized morphological structures, and similar ecological demands, such as the structure of the microhabitat, often lead to convergent or parallel evolution. The evolution of adhesive toepads in geckos remains understudied because of the paucity of phylogenetically-informed investigations of candidate clades exhibiting purported incipient expression of these (i.e. species having evolved some, but not all, parts of the complex adhesive system of pad-bearing geckos). Using Cyrtodactylus, a speciose genus with well-established ecotypes, we tested the hypothesis that microhabitats that require more climbing will lead to the acquisition of incipient adhesive morphology. We measured subdigital scale area, a proxy for adhesive toepad evolution, and quantified subdigital scale shape for 77 of the 354 described species, including at least one representative of each ecotype. Subdigital scale area increased from terrestrial through generalist and saxicoline (rock-dwelling) to arboreal ecotypes, with subdigital scale shape evolving from ancestral conditions for padless lizards to lateromedially expanded lamella-like scales only in the arboreal ecotypes. This significant link between phenotype and environment supports the contention that scansorial, and particularly arboreal, Cyrtodactylus ecotypes have evolved incipiently expressed adhesive toepads. This highlights the suitability of this genus as a model system for studying the ecology and evolution of adhesive toepads as well as being a promising candidate for research on adaptive radiations.
    Wissenschaftlicher Artikel
    Band:
    Heft:
      50