Evolution of eggshell structure in relation to nesting ecology in non-avian reptiles
(2021) In Journal of Morphology 282(7). p.1066-1079- Abstract
Amniotic eggs are multifunctional structures that enabled early tetrapods to colonize the land millions of years ago, and are now the reproductive mode of over 70% of all terrestrial amniotes. Eggshell morphology is at the core of animal survival, mediating the interactions between embryos and their environment, and has evolved into a massive diversity of forms and functions in modern reptiles. These functions are critical to embryonic survival and may serve as models for new antimicrobial and/or breathable membranes. However, we still lack critical data on the basic structural and functional properties of eggs, particularly of reptiles. Here, we first characterized egg shape, shell thickness, porosity, and mineralization of eggs from... (More)
Amniotic eggs are multifunctional structures that enabled early tetrapods to colonize the land millions of years ago, and are now the reproductive mode of over 70% of all terrestrial amniotes. Eggshell morphology is at the core of animal survival, mediating the interactions between embryos and their environment, and has evolved into a massive diversity of forms and functions in modern reptiles. These functions are critical to embryonic survival and may serve as models for new antimicrobial and/or breathable membranes. However, we still lack critical data on the basic structural and functional properties of eggs, particularly of reptiles. Here, we first characterized egg shape, shell thickness, porosity, and mineralization of eggs from 91 reptile species using optical images, scanning electron microscopy, and micro computed tomography, and collected data on nesting ecology from the literature. We then used comparative analyses to test hypotheses on the selective pressures driving their evolution. We hypothesized that eggshell morphology has evolved to protect shells from physical damage and desiccation, and, in support, found a positive relationship between thickness and precipitation, and a negative relationship between porosity and temperature. Although mineralization varied extensively, it was not correlated with nesting ecology variables. Ancestral state reconstructions show thinning and increased porosity over evolutionary time in squamates, but the opposite in turtles and crocodilians. Egg shape, size, porosity and calcification were correlated, suggesting potential structural or developmental tradeoffs. This study provides new data and insights into the morphology and evolution of reptile eggs, and raises numerous questions for additional research.
(Less)
- author
- D'Alba, Liliana ; Goldenberg, Jonathan LU ; Nallapaneni, Asritha ; Parkinson, Dilworth Y ; Zhu, Chenhui ; Vanthournout, Bram and Shawkey, Matthew D
- publishing date
- 2021-07
- type
- Contribution to journal
- publication status
- published
- keywords
- Alligators and Crocodiles, Animals, Ecology, Egg Shell, Turtles, X-Ray Microtomography
- in
- Journal of Morphology
- volume
- 282
- issue
- 7
- pages
- 1066 - 1079
- publisher
- John Wiley & Sons Inc.
- external identifiers
-
- scopus:85104529994
- pmid:33713039
- ISSN
- 1097-4687
- DOI
- 10.1002/jmor.21347
- language
- English
- LU publication?
- no
- additional info
- © 2021 Wiley Periodicals LLC.
- id
- e09eb3c1-3652-4f59-863e-14578f85cd54
- date added to LUP
- 2023-02-07 10:47:21
- date last changed
- 2024-04-28 08:38:20
@article{e09eb3c1-3652-4f59-863e-14578f85cd54,
abstract = {{<p>Amniotic eggs are multifunctional structures that enabled early tetrapods to colonize the land millions of years ago, and are now the reproductive mode of over 70% of all terrestrial amniotes. Eggshell morphology is at the core of animal survival, mediating the interactions between embryos and their environment, and has evolved into a massive diversity of forms and functions in modern reptiles. These functions are critical to embryonic survival and may serve as models for new antimicrobial and/or breathable membranes. However, we still lack critical data on the basic structural and functional properties of eggs, particularly of reptiles. Here, we first characterized egg shape, shell thickness, porosity, and mineralization of eggs from 91 reptile species using optical images, scanning electron microscopy, and micro computed tomography, and collected data on nesting ecology from the literature. We then used comparative analyses to test hypotheses on the selective pressures driving their evolution. We hypothesized that eggshell morphology has evolved to protect shells from physical damage and desiccation, and, in support, found a positive relationship between thickness and precipitation, and a negative relationship between porosity and temperature. Although mineralization varied extensively, it was not correlated with nesting ecology variables. Ancestral state reconstructions show thinning and increased porosity over evolutionary time in squamates, but the opposite in turtles and crocodilians. Egg shape, size, porosity and calcification were correlated, suggesting potential structural or developmental tradeoffs. This study provides new data and insights into the morphology and evolution of reptile eggs, and raises numerous questions for additional research.</p>}},
author = {{D'Alba, Liliana and Goldenberg, Jonathan and Nallapaneni, Asritha and Parkinson, Dilworth Y and Zhu, Chenhui and Vanthournout, Bram and Shawkey, Matthew D}},
issn = {{1097-4687}},
keywords = {{Alligators and Crocodiles; Animals; Ecology; Egg Shell; Turtles; X-Ray Microtomography}},
language = {{eng}},
number = {{7}},
pages = {{1066--1079}},
publisher = {{John Wiley & Sons Inc.}},
series = {{Journal of Morphology}},
title = {{Evolution of eggshell structure in relation to nesting ecology in non-avian reptiles}},
url = {{http://dx.doi.org/10.1002/jmor.21347}},
doi = {{10.1002/jmor.21347}},
volume = {{282}},
year = {{2021}},
}