Bailey K Howell, Kristin M Winchell, Travis J Hagey
{"title":"Geometric Morphometrics Reveal Shape Differences in the Toes of Urban Lizards.","authors":"Bailey K Howell, Kristin M Winchell, Travis J Hagey","doi":"10.1093/iob/obac028","DOIUrl":null,"url":null,"abstract":"<p><p>Urbanization, despite its destructive effects on natural habitats, offers species an opportunity to colonize novel niches. Previous research found that urban <i>Anolis</i> lizards in Puerto Rico had increased adhesive toepad area and more ventral toepad scales, traits that are likely adaptive and genetically based. We further investigated these phenotypic changes using geometric morphometrics to measure differences in toe shape, toepad shape, and lamellar morphology. Our results indicate that the increased toepad area of urban <i>Anolis cristatellus</i> lizards in Puerto Rico is not simply an isometric increase in toe size. Toes of urban populations exhibit multiple disproportional changes compared to forest lizards, with a larger proportion of the toe length covered in adhesive toepad. In addition, the toepads of urban lizards increase more in length than width. Lastly, lizards in urban populations exhibit both increased number of lamellae as well as increased spacing between individual lamellae. We also observed regional variation, with urban specimens having significantly more disparity, suggesting similar processes of urban adaptation are likely happening in parallel across the island, yet with region-specific idiosyncrasies, possibly generating more variation in toepad morphology across urban specimens as compared to forest specimens. Considering the use of geometric morphometrics, we found that specimen preparation, specifically how flat and straight toes are during imaging, to be an important factor affecting our data, more so than specimen size or any other meaningful morphological variation. In addition, we found that landmark and semilandmark data can be used to directly estimate toepad area, offering the opportunity to streamline future studies. In conclusion, our results highlight the value of considering toepad morphology in more detail beyond adhesive pad area or number of lamellae. Geometric morphometrics tools may be employed to elucidate subtle differences in shape to better allow researchers to connect changes in morphology to ecology and adhesive performance.</p>","PeriodicalId":2,"journal":{"name":"ACS Applied Bio Materials","volume":" ","pages":"obac028"},"PeriodicalIF":4.6000,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9391197/pdf/","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Applied Bio Materials","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/iob/obac028","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2022/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"MATERIALS SCIENCE, BIOMATERIALS","Score":null,"Total":0}
引用次数: 3
Abstract
Urbanization, despite its destructive effects on natural habitats, offers species an opportunity to colonize novel niches. Previous research found that urban Anolis lizards in Puerto Rico had increased adhesive toepad area and more ventral toepad scales, traits that are likely adaptive and genetically based. We further investigated these phenotypic changes using geometric morphometrics to measure differences in toe shape, toepad shape, and lamellar morphology. Our results indicate that the increased toepad area of urban Anolis cristatellus lizards in Puerto Rico is not simply an isometric increase in toe size. Toes of urban populations exhibit multiple disproportional changes compared to forest lizards, with a larger proportion of the toe length covered in adhesive toepad. In addition, the toepads of urban lizards increase more in length than width. Lastly, lizards in urban populations exhibit both increased number of lamellae as well as increased spacing between individual lamellae. We also observed regional variation, with urban specimens having significantly more disparity, suggesting similar processes of urban adaptation are likely happening in parallel across the island, yet with region-specific idiosyncrasies, possibly generating more variation in toepad morphology across urban specimens as compared to forest specimens. Considering the use of geometric morphometrics, we found that specimen preparation, specifically how flat and straight toes are during imaging, to be an important factor affecting our data, more so than specimen size or any other meaningful morphological variation. In addition, we found that landmark and semilandmark data can be used to directly estimate toepad area, offering the opportunity to streamline future studies. In conclusion, our results highlight the value of considering toepad morphology in more detail beyond adhesive pad area or number of lamellae. Geometric morphometrics tools may be employed to elucidate subtle differences in shape to better allow researchers to connect changes in morphology to ecology and adhesive performance.
期刊介绍:
ACS Applied Bio Materials is an interdisciplinary journal publishing original research covering all aspects of biomaterials and biointerfaces including and beyond the traditional biosensing, biomedical and therapeutic applications.
The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrates knowledge in the areas of materials, engineering, physics, bioscience, and chemistry into important bio applications. The journal is specifically interested in work that addresses the relationship between structure and function and assesses the stability and degradation of materials under relevant environmental and biological conditions.