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Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA

How species will respond to ongoing and future climate change is one of the most important questions facing biodiversity scientists today. The fossil record provides unparalleled insight into past ecological and evolutionary responses to climate change, but the resource remains virtually untapped fo...

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Autores principales: Moroz, Molly, Jackson, Illiam S.C., Ramirez, Daniel, Kemp, Melissa E.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: PeerJ Inc. 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971077/
https://www.ncbi.nlm.nih.gov/pubmed/33777514
http://dx.doi.org/10.7717/peerj.10856
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author Moroz, Molly
Jackson, Illiam S.C.
Ramirez, Daniel
Kemp, Melissa E.
author_facet Moroz, Molly
Jackson, Illiam S.C.
Ramirez, Daniel
Kemp, Melissa E.
author_sort Moroz, Molly
collection PubMed
description How species will respond to ongoing and future climate change is one of the most important questions facing biodiversity scientists today. The fossil record provides unparalleled insight into past ecological and evolutionary responses to climate change, but the resource remains virtually untapped for many organisms. We use geometric morphometrics and a 25,000 year fossil record to quantify changes in body size and mandible shape through time and across climate regimes for two bat species present in Quaternary paleontological deposits of central Texas: Myotis velifer, a bat distributed throughout the Southwestern US and Mexico that is still found in central Texas today, and Eptesicus fuscus, a bat widely distributed throughout North America that has been extirpated in central Texas. Because of ecogeographic rules like Bergmann’s rule, which posits that endotherms are larger in colder environments, we hypothesized that both species were larger during cooler time intervals. Additionally, we hypothesized that both species would show variation in dental morphology across the studied sequence as a response to climate change. While we found a decrease in centroid size–a proxy for ­­body size–through time for both species, we could not establish a clear relationship between centroid size and temperature alone. However, we did find that specimens from drier environments were significantly larger than those from wetter ones. Furthermore, we found significant dental shape variation between environments reflecting different temperature levels for both species. Yet only M. velifer exhibited significant variation between environments of varying precipitation levels. This result was surprising because present-day populations of E. fuscus are highly variable across both temperature and precipitation gradients. We determined that the morphological change experienced by M. velifer through time, and between warmer and cooler temperatures, was associated with the coronoid process, condylar process, and the mandibular symphysis. These parts play a pivotal role in bite force, so changes in these features might relate to changes in diet. We show that long-term datasets derived from fossil material provide invaluable insight not only into the validity of ecogeographic rules, but also into the adaptive capacities of extant taxa when faced with environmental changes. Our results highlight diverging responses to a variety of climate factors that are relevant to consider in biodiversity research given ongoing global change.
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spelling pubmed-79710772021-03-25 Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA Moroz, Molly Jackson, Illiam S.C. Ramirez, Daniel Kemp, Melissa E. PeerJ Ecology How species will respond to ongoing and future climate change is one of the most important questions facing biodiversity scientists today. The fossil record provides unparalleled insight into past ecological and evolutionary responses to climate change, but the resource remains virtually untapped for many organisms. We use geometric morphometrics and a 25,000 year fossil record to quantify changes in body size and mandible shape through time and across climate regimes for two bat species present in Quaternary paleontological deposits of central Texas: Myotis velifer, a bat distributed throughout the Southwestern US and Mexico that is still found in central Texas today, and Eptesicus fuscus, a bat widely distributed throughout North America that has been extirpated in central Texas. Because of ecogeographic rules like Bergmann’s rule, which posits that endotherms are larger in colder environments, we hypothesized that both species were larger during cooler time intervals. Additionally, we hypothesized that both species would show variation in dental morphology across the studied sequence as a response to climate change. While we found a decrease in centroid size–a proxy for ­­body size–through time for both species, we could not establish a clear relationship between centroid size and temperature alone. However, we did find that specimens from drier environments were significantly larger than those from wetter ones. Furthermore, we found significant dental shape variation between environments reflecting different temperature levels for both species. Yet only M. velifer exhibited significant variation between environments of varying precipitation levels. This result was surprising because present-day populations of E. fuscus are highly variable across both temperature and precipitation gradients. We determined that the morphological change experienced by M. velifer through time, and between warmer and cooler temperatures, was associated with the coronoid process, condylar process, and the mandibular symphysis. These parts play a pivotal role in bite force, so changes in these features might relate to changes in diet. We show that long-term datasets derived from fossil material provide invaluable insight not only into the validity of ecogeographic rules, but also into the adaptive capacities of extant taxa when faced with environmental changes. Our results highlight diverging responses to a variety of climate factors that are relevant to consider in biodiversity research given ongoing global change. PeerJ Inc. 2021-03-15 /pmc/articles/PMC7971077/ /pubmed/33777514 http://dx.doi.org/10.7717/peerj.10856 Text en ©2021 Moroz et al. https://creativecommons.org/licenses/by/4.0/ This is an open access article distributed under the terms of the Creative Commons Attribution License (https://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 Ecology
Moroz, Molly
Jackson, Illiam S.C.
Ramirez, Daniel
Kemp, Melissa E.
Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title_full Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title_fullStr Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title_full_unstemmed Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title_short Divergent morphological responses to millennia of climate change in two species of bats from Hall’s Cave, Texas, USA
title_sort divergent morphological responses to millennia of climate change in two species of bats from hall’s cave, texas, usa
topic Ecology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7971077/
https://www.ncbi.nlm.nih.gov/pubmed/33777514
http://dx.doi.org/10.7717/peerj.10856
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