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Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial

Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in the...

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Autores principales: Nigenda-Morales, Sergio F., Harrigan, Ryan J., Wayne, Robert K.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5877449/
https://www.ncbi.nlm.nih.gov/pubmed/29607255
http://dx.doi.org/10.7717/peerj.4512
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author Nigenda-Morales, Sergio F.
Harrigan, Ryan J.
Wayne, Robert K.
author_facet Nigenda-Morales, Sergio F.
Harrigan, Ryan J.
Wayne, Robert K.
author_sort Nigenda-Morales, Sergio F.
collection PubMed
description Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity size and pigmentation are related to the resource seasonality, heat conservation, and pathogen-resistance hypotheses, respectively. Our findings suggest that marsupials may be highly susceptible to environmental changes, and in the case of the Virginia opossum, the drastic phenotypic evolution in northern populations may have arisen rapidly, facilitating the colonization of seasonal and colder habitats of temperate North America.
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spelling pubmed-58774492018-03-30 Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial Nigenda-Morales, Sergio F. Harrigan, Ryan J. Wayne, Robert K. PeerJ Biogeography Phenotypic variation along environmental gradients can provide evidence suggesting local adaptation has shaped observed morphological disparities. These differences, in traits such as body and extremity size, as well as skin and coat pigmentation, may affect the overall fitness of individuals in their environments. The Virginia opossum (Didelphis virginiana) is a marsupial that shows phenotypic variation across its range, one that has recently expanded into temperate environments. It is unknown, however, whether the variation observed in the species fits adaptive ecogeographic patterns, or if phenotypic change is associated with any environmental factors. Using phenotypic measurements of over 300 museum specimens of Virginia opossum, collected throughout its distribution range, we applied regression analysis to determine if phenotypes change along a latitudinal gradient. Then, using predictors from remote-sensing databases and a random forest algorithm, we tested environmental models to find the most important variables driving the phenotypic variation. We found that despite the recent expansion into temperate environments, the phenotypic variation in the Virginia opossum follows a latitudinal gradient fitting three adaptive ecogeographic patterns codified under Bergmann’s, Allen’s and Gloger’s rules. Temperature seasonality was an important predictor of body size variation, with larger opossums occurring at high latitudes with more seasonal environments. Annual mean temperature predicted important variation in extremity size, with smaller extremities found in northern populations. Finally, we found that precipitation and temperature seasonality as well as low temperatures were strong environmental predictors of skin and coat pigmentation variation; darker opossums are distributed at low latitudes in warmer environments with higher precipitation seasonality. These results indicate that the adaptive mechanisms underlying the variation in body size, extremity size and pigmentation are related to the resource seasonality, heat conservation, and pathogen-resistance hypotheses, respectively. Our findings suggest that marsupials may be highly susceptible to environmental changes, and in the case of the Virginia opossum, the drastic phenotypic evolution in northern populations may have arisen rapidly, facilitating the colonization of seasonal and colder habitats of temperate North America. PeerJ Inc. 2018-03-27 /pmc/articles/PMC5877449/ /pubmed/29607255 http://dx.doi.org/10.7717/peerj.4512 Text en ©2018 Nigenda-Morales et al. http://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.
spellingShingle Biogeography
Nigenda-Morales, Sergio F.
Harrigan, Ryan J.
Wayne, Robert K.
Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title_full Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title_fullStr Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title_full_unstemmed Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title_short Playing by the rules? Phenotypic adaptation to temperate environments in an American marsupial
title_sort playing by the rules? phenotypic adaptation to temperate environments in an american marsupial
topic Biogeography
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5877449/
https://www.ncbi.nlm.nih.gov/pubmed/29607255
http://dx.doi.org/10.7717/peerj.4512
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