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Judson JM, Hoekstra LA, Janzen FJ. Demographic history and genomic signatures of selection in a widespread vertebrate ectotherm. Mol Ecol 2024; 33:e17269. [PMID: 38234254 PMCID: PMC10922411 DOI: 10.1111/mec.17269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/20/2023] [Accepted: 01/08/2024] [Indexed: 01/19/2024]
Abstract
Environmental conditions vary greatly across large geographic ranges, and yet certain species inhabit entire continents. In such species, genomic sequencing can inform our understanding of colonization history and the impact of selection on the genome as populations experience diverse local environments. As ectothermic vertebrates are among the most vulnerable to environmental change, it is critical to understand the contributions of local adaptation to population survival. Widespread ectotherms offer an opportunity to explore how species can successfully inhabit such differing environments and how future climatic shifts will impact species' survival. In this study, we investigated the widespread painted turtle (Chrysemys picta) to assess population genomic structure, demographic history, and genomic signatures of selection in the western extent of the range. We found support for a substantial role of serial founder effects in shaping population genomic structure: demographic analysis and runs of homozygosity were consistent with bottlenecks of increasing severity from eastern to western populations during and following the Last Glacial Maximum, and edge populations were more strongly diverged and had less genetic diversity than those from the centre of the range. We also detected outlier loci, but allelic patterns in many loci could be explained by either genetic surfing or selection. While range expansion complicates the identification of loci under selection, we provide candidates for future study of local adaptation in a long-lived, widespread ectotherm that faces an uncertain future as the global climate continues to rapidly change.
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Affiliation(s)
- Jessica M. Judson
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Current Address: W. K. Kellogg Biological Station, Departments of Fisheries and Wildlife & Integrative Biology, Michigan State University, Hickory Corners, MI 49060, USA
| | - Luke A. Hoekstra
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Current Address: Department of Integrative Biology, Oklahoma State University, Stillwater, OK 74078, USA
| | - Fredric J. Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Current Address: W. K. Kellogg Biological Station, Departments of Fisheries and Wildlife & Integrative Biology, Michigan State University, Hickory Corners, MI 49060, USA
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2
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Bodensteiner BL, Iverson JB, Lea CA, Milne-Zelman CL, Mitchell TS, Refsnider JM, Voves K, Warner DA, Janzen FJ. Mother knows best: nest-site choice homogenizes embryo thermal environments among populations in a widespread ectotherm. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220155. [PMID: 37427473 PMCID: PMC10331915 DOI: 10.1098/rstb.2022.0155] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 05/02/2023] [Indexed: 07/11/2023] Open
Abstract
Species with large geographical ranges provide an excellent model for studying how different populations respond to dissimilar local conditions, particularly with respect to variation in climate. Maternal effects, such as nest-site choice greatly affect offspring phenotypes and survival. Thus, maternal behaviour has the potential to mitigate the effects of divergent climatic conditions across a species' range. We delineated natural nesting areas of six populations of painted turtles (Chrysemys picta) that span a broad latitudinal range and quantified spatial and temporal variation in nest characteristics. To quantify microhabitats available for females to choose, we also identified sites within the nesting area of each location that were representative of available thermal microhabitats. Across the range, females nested non-randomly and targeted microhabitats that generally had less canopy cover and thus higher nest temperatures. Nest microhabitats differed among locations but did not predictably vary with latitude or historic mean air temperature during embryonic development. In conjunction with other studies of these populations, our results suggest that nest-site choice is homogenizing nest environments, which buffers embryos from thermally induced selection and could slow embryonic evolution. Thus, although effective at a macroclimatic scale, nest-site choice is unlikely to compensate for novel stressors that rapidly increase local temperatures. This article is part of the theme issue 'The evolutionary ecology of nests: a cross-taxon approach'.
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Affiliation(s)
- Brooke L. Bodensteiner
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
| | - John B. Iverson
- Department of Biology, Earlham College, Richmond, IN 60071, USA
| | - Carter A. Lea
- Office of Research Proposal Development, Tulane University, New Orleans, LA 70118, USA
| | | | - Timothy S. Mitchell
- College of Biological Sciences, University of Minnesota, St. Paul, MN 55108, USA
| | - Jeanine M. Refsnider
- Department of Environmental Sciences, University of Toledo, Toledo, OH 43606, USA
| | | | - Daniel A. Warner
- Department of Biological Sciences, Auburn University, Auburn, AL 36849, USA
| | - Fredric J. Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA 50011, USA
- Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA
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3
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Bowne DR. Climate and sex in turtles. GLOBAL CHANGE BIOLOGY 2023; 29:2641-2642. [PMID: 36788755 DOI: 10.1111/gcb.16635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 02/07/2023] [Indexed: 05/31/2023]
Affiliation(s)
- David R Bowne
- Department of Biological and Environmental Sciences, Elizabethtown College, Elizabethtown, Pennsylvania, USA
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4
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Roberts HP, Willey LL, Jones MT, Akre TSB, King DI, Kleopfer J, Brown DJ, Buchanan SW, Chandler HC, deMaynadier P, Winters M, Erb L, Gipe KD, Johnson G, Lauer K, Liebgold EB, Mays JD, Meck JR, Megyesy J, Mota JL, Nazdrowicz NH, Oxenrider KJ, Parren M, Ransom TS, Rohrbaugh L, Smith S, Yorks D, Zarate B. Is the future female for turtles? Climate change and wetland configuration predict sex ratios of a freshwater species. GLOBAL CHANGE BIOLOGY 2023; 29:2643-2654. [PMID: 36723260 DOI: 10.1111/gcb.16625] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 12/15/2022] [Indexed: 05/31/2023]
Abstract
Climate change and land-use change are leading drivers of biodiversity decline, affecting demographic parameters that are important for population persistence. For example, scientists have speculated for decades that climate change may skew adult sex ratios in taxa that express temperature-dependent sex determination (TSD), but limited evidence exists that this phenomenon is occurring in natural settings. For species that are vulnerable to anthropogenic land-use practices, differential mortality among sexes may also skew sex ratios. We sampled the spotted turtle (Clemmys guttata), a freshwater species with TSD, across a large portion of its geographic range (Florida to Maine), to assess the environmental factors influencing adult sex ratios. We present evidence that suggests recent climate change has potentially skewed the adult sex ratio of spotted turtles, with samples following a pattern of increased proportions of females concomitant with warming trends, but only within the warmer areas sampled. At intermediate temperatures, there was no relationship with climate, while in the cooler areas we found the opposite pattern, with samples becoming more male biased with increasing temperatures. These patterns might be explained in part by variation in relative adaptive capacity via phenotypic plasticity in nest site selection. Our findings also suggest that spotted turtles have a context-dependent and multi-scale relationship with land use. We observed a negative relationship between male proportion and the amount of crop cover (within 300 m) when wetlands were less spatially aggregated. However, when wetlands were aggregated, sex ratios remained consistent. This pattern may reflect sex-specific patterns in movement that render males more vulnerable to mortality from agricultural machinery and other threats. Our findings highlight the complexity of species' responses to both climate change and land use, and emphasize the role that landscape structure can play in shaping wildlife population demographics.
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Affiliation(s)
- H Patrick Roberts
- Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - Lisabeth L Willey
- Department of Environmental Studies, Antioch University New England, Keene, New Hampshire, USA
- American Turtle Observatory, New Salem, Massachusetts, USA
| | - Michael T Jones
- Natural Heritage and Endangered Species Program, Massachusetts Division of Fisheries and Wildlife, Westborough, Massachusetts, USA
| | - Thomas S B Akre
- Smithsonian Conservation Biology Institute, Front Royal, Virginia, USA
| | - David I King
- U.S. Forest Service, Northern Research Station, Department of Environmental Conservation, University of Massachusetts, Amherst, Massachusetts, USA
| | - John Kleopfer
- Virginia Department of Wildlife Resources, Charles City, Virginia, USA
| | - Donald J Brown
- U.S. Forest Service, Pacific Northwest Research Station, Amboy, Washington, USA
- School of Natural Resources, West Virginia University, Morgantown, West Virginia, USA
| | - Scott W Buchanan
- Division of Fish and Wildlife, Rhode Island Department of Environmental Management, West Kingston, Rhode Island, USA
| | - Houston C Chandler
- The Orianne Society, Tiger, Georgia, USA
- Department of Fish and Wildlife Conservation, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Melissa Winters
- New Hampshire Fish and Game Department, Concord, New Hampshire, USA
| | - Lori Erb
- The Mid-Atlantic Center for Herpetology and Conservation, Oley, Pennsylvania, USA
| | - Katharine D Gipe
- Pennsylvania Fish and Boat Commission, Bellefonte, Pennsylvania, USA
| | - Glenn Johnson
- Biology Department, State University of New York, Potsdam, New York, USA
| | - Kathryn Lauer
- Department of Environmental Studies, Antioch University New England, Keene, New Hampshire, USA
- American Turtle Observatory, New Salem, Massachusetts, USA
| | - Eric B Liebgold
- Department of Biological Sciences, Salisbury University, Salisbury, Maryland, USA
| | - Jonathan D Mays
- Fish and Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, Gainesville, Florida, USA
| | - Jessica R Meck
- Natural Heritage and Endangered Species Program, Massachusetts Division of Fisheries and Wildlife, Westborough, Massachusetts, USA
- Smithsonian Conservation Biology Institute, Front Royal, Virginia, USA
| | - Joshua Megyesy
- New Hampshire Fish and Game Department, Concord, New Hampshire, USA
| | - Joel L Mota
- U.S. Forest Service, Pacific Northwest Research Station, Amboy, Washington, USA
| | - Nathan H Nazdrowicz
- Species Conservation and Research Program, Delaware Division of Fish & Wildlife, Delaware, USA
| | - Kevin J Oxenrider
- West Virginia Division of Natural Resources, Romney, West Virginia, USA
| | - Molly Parren
- American Turtle Observatory, New Salem, Massachusetts, USA
| | - Tami S Ransom
- Environmental Studies Department, Salisbury University, Salisbury, Maryland, USA
| | - Lindsay Rohrbaugh
- District of Columbia Department of Energy & Environment, Washington, District of Columbia, USA
| | - Scott Smith
- Maryland Department of Natural Resources, Maryland, Wye Mills, USA
| | - Derek Yorks
- Maine Department of Inland Fisheries and Wildlife, Augusta, Maine, USA
| | - Brian Zarate
- New Jersey Division of Fish and Wildlife, Lebanon, New Jersey, USA
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5
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Deem SL, Rivera S, Nieto‐Claudin A, Emmel E, Cabrera F, Blake S. Temperature along an elevation gradient determines Galapagos tortoise sex ratios. Ecol Evol 2023; 13:e10008. [PMID: 37091568 PMCID: PMC10116026 DOI: 10.1002/ece3.10008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Revised: 03/27/2023] [Accepted: 03/31/2023] [Indexed: 04/25/2023] Open
Abstract
Climate change threatens endemic island ectothermic reptiles that display small population sizes and temperature-dependent sex determination (TSD). Studies of captive Galapagos tortoises demonstrate type A TSD with warmer incubation temperatures producing females. However, there are few published data from free-living Galapagos tortoises on incubation temperature regimes, and none on hatchling sex ratios in the wild or the potential impacts of climate change on future sex ratios. We sought to address these deficits by quantifying incubation temperatures of nests and sex ratios of juvenile tortoises along an elevation gradient on Santa Cruz Island. We focused on three geographically separated nesting zones with mean elevations of 14 m (lower), 57 m (middle), and 107 m (upper) above sea level. Nest temperatures in 54 nests distributed across the three nesting zones were measured every 4 h throughout the incubation period using iButton thermochrons. We used coelioscopy to conduct visual exams of gonads to determine the sex of 40 juvenile tortoises from the three nesting zones. During the middle trimester of incubation, the period during which sex is determined in turtles, mean nest temperatures were 25.75°C (SD = 1.08) in the upper zone, and 27.02°C (SD = 1.09), and 27.09°C (SD = 0.85) in the middle and lower zones, respectively. The proportion of juveniles that was male increased from 11.1% in the lower zone and 9.5% in the middle zone, to 80% in the upper zone. A ca. 50 m increase in elevation induced a decrease of >1.25°C in mean nest temperature during the second trimester of incubation. Over the same elevation change, the proportion of males in the juvenile tortoise population increased by ca. 70%. Temperatures on Galapagos are predicted to increase by 1-4°C over the next 50 years, which is likely to increase the frequency of female tortoises across the archipelago.
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Affiliation(s)
- Sharon L. Deem
- One Government DriveSaint Louis Zoo Institute for Conservation MedicineSt. LouisMissouriUSA
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Sam Rivera
- Department of Animal HealthZoo AtlantaAtlantaGeorgiaUSA
| | - Ainoa Nieto‐Claudin
- One Government DriveSaint Louis Zoo Institute for Conservation MedicineSt. LouisMissouriUSA
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Evan Emmel
- The Maritime Aquarium at NorwalkNorwalkConnecticutUSA
| | - Freddy Cabrera
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
| | - Stephen Blake
- Charles Darwin FoundationSanta CruzGalapagos IslandsEcuador
- Department of BiologySaint Louis UniversitySt. LouisMissouriUSA
- Max Planck Institute of Animal BehaviorRadolfzellGermany
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6
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Leivesley JA, Nancekivell EG, Brooks RJ, Litzgus JD, Rollinson N. Long-term resilience of primary sex ratios in a species with temperature-dependent sex determination after decades of climate warming. Am Nat 2022; 200:532-543. [DOI: 10.1086/720621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Topping NE, Valenzuela N. Turtle Nest-Site Choice, Anthropogenic Challenges, and Evolutionary Potential for Adaptation. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.808621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Oviparous animals, such as turtles, lay eggs whose success or demise depends on environmental conditions that influence offspring phenotype (morphology, physiology, and in many reptiles, also sex determination), growth, and survival, while in the nest and post-hatching. Consequently, because turtles display little parental care, maternal provisioning of the eggs and female nesting behavior are under strong selection. But the consequences of when and where nests are laid are affected by anthropogenic habitat disturbances that alter suitable nesting areas, expose eggs to contaminants in the wild, and modify the thermal and hydric environment experienced by developing embryos, thus impacting hatchling survival and the sexual fate of taxa with temperature-dependent sex determination (TSD) and genotypic sex determination (GSD). Indeed, global and local environmental change influences air, water, and soil temperature and moisture, which impact basking behavior, egg development, and conditions within the nest, potentially rendering current nesting strategies maladaptive as offspring mortality increases and TSD sex ratios become drastically skewed. Endocrine disruptors can sex reverse TSD and GSD embryos alike. Adapting to these challenges depends on genetic variation, and little to no heritability has been detected for nest-site behavior. However, modest heritability in threshold temperature (above and below which females or males develop in TSD taxa, respectively) exists in the wild, as well as interpopulation differences in the reaction norm of sex ratio to temperature, and potentially also in the expression of gene regulators of sexual development. If this variation reflects additive genetic components, some adaptation might be expected, provided that the pace of environmental change does not exceed the rate of evolution. Research remains urgently needed to fill current gaps in our understanding of the ecology and evolution of nest-site choice and its adaptive potential, integrating across multiple levels of organization.
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8
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Byer NW, Fountain ED, Reid BN, Miller K, Kulzer PJ, Peery MZ. Land use and life history constrain adaptive genetic variation and reduce the capacity for climate change adaptation in turtles. BMC Genomics 2021; 22:837. [PMID: 34794393 PMCID: PMC8603537 DOI: 10.1186/s12864-021-08151-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 11/01/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Rapid anthropogenic climate change will require species to adapt to shifting environmental conditions, with successful adaptation dependent upon current patterns of genetic variation. While landscape genomic approaches allow for exploration of local adaptation in non-model systems, most landscape genomics studies of adaptive capacity are limited to exploratory identification of potentially important functional genes, often without a priori expectations as to the gene functions that may be most important for climate change responses. In this study, we integrated targeted sequencing of genes of known function and genotyping of single-nucleotide polymorphisms to examine spatial, environmental, and species-specific patterns of potential local adaptation in two co-occuring turtle species: the Blanding's turtle (Emydoidea blandingii) and the snapping turtle (Chelydra serpentina). RESULTS We documented divergent patterns of spatial clustering between neutral and putatively adaptive genetic variation in both species. Environmental associations varied among gene regions and between species, with stronger environmental associations detected for genes involved in stress response and for the more specialized Blanding's turtle. Land cover appeared to be more important than climate in shaping spatial variation in functional genes, indicating that human landscape alterations may affect adaptive capacity important for climate change responses. CONCLUSIONS Our study provides evidence that responses to climate change will be contingent on species-specific adaptive capacity and past history of exposure to human land cover change.
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Affiliation(s)
| | | | - Brendan N Reid
- W.K. Kellogg Biological Station, Michigan State University, MI, 49060, Hickory Corners, USA
| | - Kristen Miller
- University of Wisconsin-Madison, 53706, Madison, WI, USA
| | - Paige J Kulzer
- University of Wisconsin-Madison, 53706, Madison, WI, USA
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9
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Orr TJ, Burns M, Hawkes K, Holekamp KE, Hook KA, Josefson CC, Kimmitt AA, Lewis AK, Lipshutz SE, Lynch KS, Sirot LK, Stadtmauer DJ, Staub NL, Wolfner MF, Hayssen V. It Takes Two to Tango: Including a Female Perspective in Reproductive Biology. Integr Comp Biol 2021; 60:796-813. [PMID: 32702091 DOI: 10.1093/icb/icaa084] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Like many scientific disciplines, the field of reproductive biology is subject to biases in terminology and research foci. For example, females are often described as coy and passive players in reproductive behaviors and are termed "promiscuous" if they engage in extra-pair copulations. Males on the other hand are viewed as actively holding territories and fighting with other males. Males are termed "multiply mating" if they mate with multiple females. Similarly, textbooks often illustrate meiosis as it occurs in males but not females. This edition of Integrative and Comparative Biology (ICB) includes a series of papers that focus on reproduction from the female perspective. These papers represent a subset of the work presented in our symposium and complementary sessions on female reproductive biology. In this round table discussion, we use a question and answer format to leverage the diverse perspectives and voices involved with the symposium in an exploration of theoretical, cultural, pedagogical, and scientific issues related to the study of female biology. We hope this dialog will provide a stepping-stone toward moving reproductive science and teaching to a more inclusive and objective framework.
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Affiliation(s)
- Teri J Orr
- Department of Biology, New Mexico State University, Las Cruces, NM 88003, USA
| | - Mercedes Burns
- Department of Biological Sciences, University of Maryland, Baltimore County, Baltimore, MD 21250, USA
| | - Kristen Hawkes
- Department of Anthropology, University of Utah, Salt Lake City, UT 84112, USA
| | - Kay E Holekamp
- Department of Integrative Biology, Michigan State University, East Lansing, MI, USA
| | - Kristin A Hook
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Chloe C Josefson
- Department of Animal and Veterinary Sciences, University of Idaho, Moscow, ID 83844, USA
| | - Abigail A Kimmitt
- Department of Biology, Texas A&M University, College Station, TX, USA
| | - A Kelsey Lewis
- Center for Research on Gender and Women & Department of Urology, University of Wisconsin-Madison, Madison, WI, USA
| | - Sara E Lipshutz
- Department of Biology, Indiana University, Bloomington, IN 47405, USA
| | - Kathleen S Lynch
- Biological Sciences, Hofstra University, Hempstead, NY 11549, USA
| | - Laura K Sirot
- Department of Biology, The College of Wooster, Wooster, OH 44691, USA
| | - Daniel J Stadtmauer
- Department of Ecology & Evolutionary Biology, Yale University, New Haven, CT 06520, USA
| | - Nancy L Staub
- Biology Department, Gonzaga University, Spokane, WA 99258, USA
| | - Mariana F Wolfner
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY, USA
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10
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Edmands S. Sex Ratios in a Warming World: Thermal Effects on Sex-Biased Survival, Sex Determination, and Sex Reversal. J Hered 2021; 112:155-164. [PMID: 33585893 DOI: 10.1093/jhered/esab006] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 02/15/2021] [Indexed: 12/20/2022] Open
Abstract
Rising global temperatures threaten to disrupt population sex ratios, which can in turn cause mate shortages, reduce population growth and adaptive potential, and increase extinction risk, particularly when ratios are male biased. Sex ratio distortion can then have cascading effects across other species and even ecosystems. Our understanding of the problem is limited by how often studies measure temperature effects in both sexes. To address this, the current review surveyed 194 published studies of heat tolerance, finding that the majority did not even mention the sex of the individuals used, with <10% reporting results for males and females separately. Although the data are incomplete, this review assessed phylogenetic patterns of thermally induced sex ratio bias for 3 different mechanisms: sex-biased heat tolerance, temperature-dependent sex determination (TSD), and temperature-induced sex reversal. For sex-biased heat tolerance, documented examples span a large taxonomic range including arthropods, chordates, protists, and plants. Here, superior heat tolerance is more common in females than males, but the direction of tolerance appears to be phylogenetically fluid, perhaps due to the large number of contributing factors. For TSD, well-documented examples are limited to reptiles, where high temperature usually favors females, and fishes, where high temperature consistently favors males. For temperature-induced sex reversal, unambiguous cases are again limited to vertebrates, and high temperature usually favors males in fishes and amphibians, with mixed effects in reptiles. There is urgent need for further work on the full taxonomic extent of temperature-induced sex ratio distortion, including joint effects of the multiple contributing mechanisms.
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Affiliation(s)
- Suzanne Edmands
- Department of Biological Sciences, University of Southern California, Los Angeles, CA, USA
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11
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Carter AL, Janzen FJ. Predicting the effects of climate change on incubation in reptiles: methodological advances and new directions. J Exp Biol 2021; 224:224/Suppl_1/jeb236018. [PMID: 33627463 DOI: 10.1242/jeb.236018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The unprecedented advancement of global climate change is affecting thermal conditions across spatial and temporal scales. Reptiles with temperature-dependent sex determination (TSD) are uniquely vulnerable to even fine-scale variation in incubation conditions and are a model system for investigating the impacts of shifting temperatures on key physiological and life-history traits. The ways in which current and predicted future climatic conditions translate from macro- to ultra-fine scale temperature traces in subterranean nests is insufficiently understood. Reliably predicting the ways in which fine-scale, daily and seasonally fluctuating nest temperatures influence embryonic development and offspring phenotypes is a goal that remains constrained by many of the same logistical challenges that have persisted throughout more than four decades of research on TSD. However, recent advances in microclimate and developmental modeling should allow us to move farther away from relatively coarse metrics with limited predictive capacity and towards a fully mechanistic model of TSD that can predict incubation conditions and phenotypic outcomes for a variety of reptile species across space and time and for any climate scenario.
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Affiliation(s)
- A L Carter
- Michigan State University, Kellogg Biological Station, 3700 E Gull Lake Drive, Hickory Corners, MI 49060, USA.,Iowa State University, Department of Ecology, Evolution and Organismal Biology, 2200 Osborn Drive, 251 Bessey Hall, Ames, IA 50011, USA
| | - Fredric J Janzen
- Michigan State University, Kellogg Biological Station, 3700 E Gull Lake Drive, Hickory Corners, MI 49060, USA .,Iowa State University, Department of Ecology, Evolution and Organismal Biology, 2200 Osborn Drive, 251 Bessey Hall, Ames, IA 50011, USA
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12
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Delaney DM, Hoekstra LA, Janzen FJ. Age Predicts Risky Investment Better Than Residual Reproductive Value. Am Nat 2021; 197:461-472. [PMID: 33755533 DOI: 10.1086/713174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AbstractLife-history theory predicts that investment in reproduction should increase as future reproductive potential (i.e., residual reproductive value [RRV]) decreases. Researchers have thus intuitively used age as a proxy for RRV and assume that RRV decreases with age when interpreting age-specific investment. Yet age is an imperfect proxy for RRV and may even be a poor correlate in some systems. We used a 31-year study of the nesting ecology of painted turtles (Chrysemys picta) to assess how age and RRV compare in explaining variation in a risky investment behavior. We predicted that RRV would be a better predictor of risky investment than age because RRV accounts for variation in future reproductive potential across life. We found that RRV was high in early life, slowly decreased until midlife, and then steadily decreased to terminal reproduction. However, age predicted risky behavior better than RRV. This finding suggests that stronger correlates of age (e.g., size) may be more responsible for this behavior in turtles. This study highlights that researchers should not assume that age-specific investment is driven by RRV and that future work should quantify RRV to more directly test this key element of life-history theory.
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13
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Crowley PH, Labonne J. Theory of environmental sex determination: Trending populations in stressful environments. Evolution 2021; 75:794-805. [PMID: 33492683 DOI: 10.1111/evo.14176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 01/05/2021] [Accepted: 01/13/2021] [Indexed: 11/26/2022]
Abstract
Species that have sex determined by environmental conditions during development (i.e., environmental sex determination [ESD]) are especially vulnerable to environmental change, including altered stress levels, habitat loss, and species translocations. These factors can produce multigenerational trends in population size and eco-evolutionary dynamics not captured by existing theory based on lifetime reproductive success (R0 ). Here, we extend ESD theory to use per capita growth rate r as a more appropriate measure of evolutionary success (fitness), and we demonstrate the importance of this change when males and females can differ in maturation times and when maturation times vary with local conditions (plasticity). In these cases, we show that primary and secondary sex ratios may be strongly biased; that optimal maturation times, when locally plastic, depend on the balance between mortality and growth effects; and that plasticity of maturation times can ameliorate fitness costs of increasing environmental stress.
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Affiliation(s)
- Philip H Crowley
- Department of Biology, University of Kentucky, Lexington, Kentucky, 40506.,ECOBIOP Université de Pau et des Pays de l'Adour, E2S UPPA, INRAE, ECOBIOP, Saint-Pée-sur-Nivelle, France
| | - Jacques Labonne
- ECOBIOP Université de Pau et des Pays de l'Adour, E2S UPPA, INRAE, ECOBIOP, Saint-Pée-sur-Nivelle, France
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14
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Hedrick AR, Greene DU, Lewis EL, Hood AS, Iverson JB. Climate effects on nesting phenology in Nebraska turtles. Ecol Evol 2021; 11:1225-1239. [PMID: 33598126 PMCID: PMC7863389 DOI: 10.1002/ece3.7105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 10/29/2020] [Accepted: 11/04/2020] [Indexed: 12/03/2022] Open
Abstract
A frequent response of organisms to climate change is altering the timing of reproduction, and advancement of reproductive timing has been a common reaction to warming temperatures in temperate regions. We tested whether this pattern applied to two common North American turtle species over the past three decades in Nebraska, USA. The timing of nesting (either first date or average date) of the Common Snapping Turtle (Chelydra serpentina) was negatively correlated with mean December maximum temperatures of the preceding year and mean May minimum and maximum temperatures in the nesting year and positively correlated with precipitation in July of the previous year. Increased temperatures during the late winter and spring likely permit earlier emergence from hibernation, increased metabolic rates and feeding opportunities, and accelerated vitellogenesis, ovulation, and egg shelling, all of which could drive earlier nesting. However, for the Painted Turtle (Chrysemys picta), the timing of nesting was positively correlated with mean minimum temperatures in September, October, December of the previous year, February of the nesting year, and April precipitation. These results suggest warmer fall, and winter temperature may impose an increased metabolic cost to painted turtles that impedes fall vitellogenesis, and April rains may slow the completion of vitellogenesis through decreased basking opportunities. For both species, nest deposition was highly correlated with body size, and larger females nested earlier in the season. Although average annual ambient temperatures have increased over the last four decades of our overall fieldwork at our study site, spring temperatures have not yet increased, and hence, nesting phenology has not advanced at our site for Chelydra. While Chrysemys exhibited a weak trend toward later nesting, this response was likely due to increased recruitment of smaller females into the population due to nest protection and predator control (Procyon lotor) in the early 2000s. Should climate change result in an increase in spring temperatures, nesting phenology would presumably respond accordingly, conditional on body size variation within these populations.
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Affiliation(s)
- Ashley R. Hedrick
- Department of BiologyEarlham CollegeRichmondINUSA
- Department of Ecology, Evolution, and Organismal BiologyIowa State UniversityAmesIAUSA
| | | | - Erin L. Lewis
- Department of BiologyEarlham CollegeRichmondINUSA
- Department of BiologyUtah State UniversityLoganUTUSA
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15
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Byer NW, Reid BN, Thiel RP, Peery MZ. Strong Climate Associations but No Temporal Trends in Nesting Phenology of Blanding's Turtles (Emydoidea blandingii). HERPETOLOGICA 2020. [DOI: 10.1655/herpetologica-d-20-00013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Nathan W. Byer
- Department of Natural Resources and Environmental Science, University of Nevada–Reno, Reno, NV 89503, USA
| | - Brendan N. Reid
- W.K. Kellogg Biological Station, Michigan State University, Hickory Corners, MI 49060, USA
| | - Richard P. Thiel
- Wisconsin Department of Natural Resources (retired), 7167 Deuce Road, Tomah, WI 54660, USA
| | - M. Zachariah Peery
- Department of Forest and Wildlife Ecology, University of Wisconsin–Madison, Madison, WI 53706, USA
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16
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Vandeputte M, Clota F, Sadoul B, Blanc M, Blondeau‐Bidet E, Bégout M, Cousin X, Geffroy B. Low temperature has opposite effects on sex determination in a marine fish at the larval/postlarval and juvenile stages. Ecol Evol 2020; 10:13825-13835. [PMID: 33391683 PMCID: PMC7771145 DOI: 10.1002/ece3.6972] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 10/09/2020] [Accepted: 10/11/2020] [Indexed: 12/14/2022] Open
Abstract
Temperature-dependent sex determination (TSD) can be observed in multiple reptile and fish species. It is adaptive when varying environmental conditions advantage either males or females. A good knowledge of the thermosensitive period is key to understand how environmental changes may lead to changes in population sex ratio. Here, by manipulating temperature during development, we confirm that cold temperature (16°C) increases the proportion of fish that develop as females in European sea bass (Dicentrarchus labrax) until 56 days posthatching, but show that it has an opposite effect at later stages, with the proportion of males reaching ~90% after 230 days at 16°C. This is the first observation of opposite effects of temperature at different time periods on the sex ratio of a vertebrate. Our results highlight the potential complexity of environmental effects on sex determination.
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Affiliation(s)
- Marc Vandeputte
- Université Paris‐Saclay, INRAE, AgroParisTechGABIJouy‐en‐JosasFrance
- MARBEC, Univ. Montpellier, CNRS, IfremerIRDPalavas‐les‐FlotsFrance
| | - Frédéric Clota
- Université Paris‐Saclay, INRAE, AgroParisTechGABIJouy‐en‐JosasFrance
- MARBEC, Univ. Montpellier, CNRS, IfremerIRDPalavas‐les‐FlotsFrance
| | - Bastien Sadoul
- MARBEC, Univ. Montpellier, CNRS, IfremerIRDPalavas‐les‐FlotsFrance
| | | | | | | | - Xavier Cousin
- Université Paris‐Saclay, INRAE, AgroParisTechGABIJouy‐en‐JosasFrance
- MARBEC, Univ. Montpellier, CNRS, IfremerIRDPalavas‐les‐FlotsFrance
| | - Benjamin Geffroy
- MARBEC, Univ. Montpellier, CNRS, IfremerIRDPalavas‐les‐FlotsFrance
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17
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Castelli MA, Georges A, Cherryh C, Rosauer DF, Sarre SD, Contador‐Kelsall I, Holleley CE. Evolving thermal thresholds explain the distribution of temperature sex reversal in an Australian dragon lizard. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13203] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Affiliation(s)
- Meghan A. Castelli
- Institute for Applied Ecology University of Canberra Canberra Australian Capital Territory Australia
- Australian National Wildlife CollectionCSIRO National Research Collections Australia Canberra Australian Capital Territory Australia
| | - Arthur Georges
- Institute for Applied Ecology University of Canberra Canberra Australian Capital Territory Australia
| | - Caitlin Cherryh
- Australian National Wildlife CollectionCSIRO National Research Collections Australia Canberra Australian Capital Territory Australia
- Department of Ecology and Evolution Research School of Biology Australian National University Canberra Australian Capital Territory Australia
| | - Dan F. Rosauer
- Department of Ecology and Evolution Research School of Biology Australian National University Canberra Australian Capital Territory Australia
| | - Stephen D. Sarre
- Institute for Applied Ecology University of Canberra Canberra Australian Capital Territory Australia
| | - Isabella Contador‐Kelsall
- School of Earth, Atmospheric and Life Sciences University of Wollongong Wollongong New South Wales Australia
| | - Clare E. Holleley
- Institute for Applied Ecology University of Canberra Canberra Australian Capital Territory Australia
- Australian National Wildlife CollectionCSIRO National Research Collections Australia Canberra Australian Capital Territory Australia
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18
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Hattori RS, Castañeda-Cortés DC, Arias Padilla LF, Strobl-Mazzulla PH, Fernandino JI. Activation of stress response axis as a key process in environment-induced sex plasticity in fish. Cell Mol Life Sci 2020; 77:4223-4236. [PMID: 32367192 PMCID: PMC11104976 DOI: 10.1007/s00018-020-03532-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/26/2020] [Accepted: 04/15/2020] [Indexed: 12/16/2022]
Abstract
The determination of sex is an important hallmark in the life cycle of organisms, in which the fate of gonads and then the individual sex are defined. In gonochoristic teleost fish, this process is characterized by a high plasticity, considering that in spite of genotypic sex many environmental factors can cause shifts from one to another molecular pathway, resulting in organisms with mismatching genotypic and phenotypic sexes. Interestingly, in most instances, both female-to-male or male-to-female sex-reversed individuals develop functional gonads with normal gametogenesis and respective progenies with full viability. The study of these mechanisms is being spread to other non-model species or to those inhabiting more extreme environmental conditions. Although water temperature is an important mechanism involved in sex determination, there are other environmental stressors affected by the climate change which are also implicated in stress response-induced masculinization in fish. In this regard, the brain has emerged as the transducer of the environment input that can influence the gonadal fate. Furthermore, the evaluation of other environmental stressors or their synergic effect on sex determination at conditions that simulate the natural environments is growing gradually. Within such scope, the concerns related to climate change impacts rely on the fact that many of biotic and abiotic parameters reported to affect sex ratios are expected to increase concomitantly as a result of increased greenhouse gas emissions and, particularly worrying, many of them are related to male bias in the populations, such as high temperature, hypoxia, and acidity. These environmental changes can also generate epigenetic changes in sex-related genes affecting their expression, with implications on sex differentiation not only of exposed individuals but also in following generations. The co-analysis of multi-stressors with potential inter- and transgenerational effects is essential to allow researchers to perform long-term predictions on climate change impacts in wild populations and for establishing highly accurate monitoring tools and suitable mitigation strategies.
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Affiliation(s)
- R S Hattori
- Salmonid Experimental Station at Campos do Jordão, UPD-CJ (APTA/SAA), Campos do Jordão, Brazil
| | - D C Castañeda-Cortés
- Laboratorio de Biología del Desarrollo, Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Argentina
| | - L F Arias Padilla
- Laboratorio de Biología del Desarrollo, Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Argentina
| | - P H Strobl-Mazzulla
- Laboratorio de Biología del Desarrollo, Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Argentina
| | - J I Fernandino
- Laboratorio de Biología del Desarrollo, Instituto Tecnológico de Chascomús (CONICET-UNSAM), Chascomús, Argentina.
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19
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Bodensteiner BL, Agudelo‐Cantero GA, Arietta AZA, Gunderson AR, Muñoz MM, Refsnider JM, Gangloff EJ. Thermal adaptation revisited: How conserved are thermal traits of reptiles and amphibians? JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2020; 335:173-194. [DOI: 10.1002/jez.2414] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 07/17/2020] [Accepted: 09/04/2020] [Indexed: 12/31/2022]
Affiliation(s)
- Brooke L. Bodensteiner
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut USA
| | - Gustavo A. Agudelo‐Cantero
- Department of Physiology, Institute of Biosciences University of São Paulo São Paulo Brazil
- Department of Biology ‐ Genetics, Ecology, and Evolution Aarhus University Aarhus Denmark
| | | | - Alex R. Gunderson
- Department of Ecology and Evolutionary Biology Tulane University New Orleans Louisiana USA
| | - Martha M. Muñoz
- Department of Ecology and Evolutionary Biology Yale University New Haven Connecticut USA
| | | | - Eric J. Gangloff
- Department of Zoology Ohio Wesleyan University Delaware Ohio USA
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20
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Delaney DM, Hoekstra LA, Janzen FJ. Becoming creatures of habit: Among- and within-individual variation in nesting behaviour shift with age. J Evol Biol 2020; 33:1614-1624. [PMID: 32897610 DOI: 10.1111/jeb.13701] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 08/24/2020] [Accepted: 08/31/2020] [Indexed: 11/29/2022]
Abstract
The quantification of repeatability has enabled behavioural and evolutionary ecologists to assess the heritable potential of traits. For behavioural traits that vary across life, age-related variation should be accounted for to prevent biasing the microevolutionary estimate of interest. Moreover, to gain a mechanistic understanding of ontogenetic variation in behaviour, among- and within-individual variance should be quantified across life. We leveraged a 30-year study of painted turtles (Chrysemys picta) to assess how age contributes to variation in the repeatability of nesting behaviours. We found that four components of nesting behaviour were repeatable and that accounting for age increased the repeatability estimate for maternal choice of canopy cover over nests. We detected canalization (diminished within-individual variance with age) of canopy cover choice in a reduced data set despite no shift in repeatability. Additionally, random regression analysis revealed that females became more divergent from each other in their choice of canopy cover with age. Thus, properly modelling age-related variance should more precisely estimate heritable potential, and assessing among- and within-individual variance components in addition to repeatability will offer a more mechanistic understanding of behavioural variation across age.
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Affiliation(s)
- David M Delaney
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.,Department of Ecology and Evolutionary Biology, University of Colorado Boulder, Boulder, CO, USA
| | - Luke A Hoekstra
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.,Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA
| | - Fredric J Janzen
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, IA, USA.,Kellogg Biological Station, Michigan State University, Hickory Corners, MI, USA
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21
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Lamont MM, Johnson D, Carthy RR. The incubation environment of nests deposited by a genetically distinct group of loggerhead sea turtles in Northwest Florida. Glob Ecol Conserv 2020. [DOI: 10.1016/j.gecco.2020.e01070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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22
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Bock SL, Lowers RH, Rainwater TR, Stolen E, Drake JM, Wilkinson PM, Weiss S, Back B, Guillette L, Parrott BB. Spatial and temporal variation in nest temperatures forecasts sex ratio skews in a crocodilian with environmental sex determination. Proc Biol Sci 2020; 287:20200210. [PMID: 32345164 DOI: 10.1098/rspb.2020.0210] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Species displaying temperature-dependent sex determination (TSD) are especially vulnerable to the effects of a rapidly changing global climate due to their profound sensitivity to thermal cues during development. Predicting the consequences of climate change for these species, including skewed offspring sex ratios, depends on understanding how climatic factors interface with features of maternal nesting behaviour to shape the developmental environment. Here, we measure thermal profiles in 86 nests at two geographically distinct sites in the northern and southern regions of the American alligator's (Alligator mississippiensis) geographical range, and examine the influence of both climatic factors and maternally driven nest characteristics on nest temperature variation. Changes in daily maximum air temperatures drive annual trends in nest temperatures, while variation in individual nest temperatures is also related to local habitat factors and microclimate characteristics. Without any compensatory nesting behaviours, nest temperatures are projected to increase by 1.6-3.7°C by the year 2100, and these changes are predicted to have dramatic consequences for offspring sex ratios. Exact sex ratio outcomes vary widely depending on site and emission scenario as a function of the unique temperature-by-sex reaction norm exhibited by all crocodilians. By revealing the ecological drivers of nest temperature variation in the American alligator, this study provides important insights into the potential consequences of climate change for crocodilian species, many of which are already threatened by extinction.
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Affiliation(s)
- Samantha L Bock
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Savannah River Ecology Laboratory, Aiken, SC 29802, USA
| | - Russell H Lowers
- Integrated Mission Support Services, John F. Kennedy Space Center, FL 32899, USA
| | - Thomas R Rainwater
- Tom Yawkey Wildlife Center, Georgetown, SC 29440, USA.,Belle W. Baruch Institute of Coastal Ecology & Forest Science, Clemson University, Georgetown, SC 29442, USA
| | - Eric Stolen
- Integrated Mission Support Services, John F. Kennedy Space Center, FL 32899, USA
| | - John M Drake
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA 30602, USA
| | | | - Stephanie Weiss
- Integrated Mission Support Services, John F. Kennedy Space Center, FL 32899, USA
| | - Brenton Back
- Integrated Mission Support Services, John F. Kennedy Space Center, FL 32899, USA
| | - Louis Guillette
- Medical University of South Carolina, Hollings Marine Laboratory, Charleston, SC 29412, USA
| | - Benjamin B Parrott
- Odum School of Ecology, University of Georgia, Athens, GA 30602, USA.,Savannah River Ecology Laboratory, Aiken, SC 29802, USA
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23
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Rowe CL, Liang D, Woodland RJ. Effects of constant and fluctuating incubation temperatures on hatching success and hatchling traits in the diamondback terrapin (Malaclemys terrapin) in the context of the warming climate. J Therm Biol 2020; 88:102528. [PMID: 32126003 DOI: 10.1016/j.jtherbio.2020.102528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2019] [Revised: 01/23/2020] [Accepted: 01/27/2020] [Indexed: 10/25/2022]
Abstract
As global temperatures continue to rise, so too will the nest temperatures of many species of turtles. Yet for most turtle species, including the estuarine diamondback terrapin (Malaclemys terrapin), there is limited information on embryonic sensitivity to elevated temperature. We incubated eggs of M. terrapin at three, mean temperatures (31, 34, 37 °C) under two thermal exposure regimes (constant or semi-naturally fluctuating temperature) and measured hatching success, developmental rate, and hatchling size. Hatching success was 100% at 31 °C and 67% at 34 °C, respectively; at 37 °C, all eggs failed early in the incubation period. These values were unaffected by exposure regime. The modeled LT50 (temperature that was lethal to 50% of the test population) was 34.0 °C in the constant and 34.2 °C in the fluctuating thermal regime, reflecting a steep decline in survival between 33 and 35 °C. Hatchlings having been incubated at a constant 34 °C hatched sooner than those incubated at 31 °C under either constant or fluctuating temperature. Hatchlings were smaller in straight carapace length (CL) and width after having been incubated at 34 °C compared to 31 °C. Larger (CL) hatchlings resulted from fluctuating temperature conditions relative to constant temperature conditions, regardless of mean temperature. Based upon recent temperatures in natural nests, the M. terrapin population studied here appears to possess resiliency to several degrees of elevated mean nest temperatures, beyond which, embryonic mortality will likely sharply increase. When considered within the mosaic of challenges that Maryland's M. terrapin face as the climate warms, including ongoing habitat losses due to sea level rise and impending thermal impacts on bioenergetics and offspring sex ratios, a future increase in embryonic mortality could be a critical factor for a population already experiencing ecological and physiological challenges due to climate change.
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Affiliation(s)
- Christopher L Rowe
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA.
| | - Dong Liang
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA
| | - Ryan J Woodland
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, 146 Williams Street, P.O. Box 38, Solomons, MD, 20688, USA
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24
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Carter AW, Paitz RT, Bowden RM. The Devil is in the Details: Identifying Aspects of Temperature Variation that Underlie Sex Determination in Species with TSD. Integr Comp Biol 2020; 59:1081-1088. [PMID: 31095337 DOI: 10.1093/icb/icz036] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Most organisms experience thermal variability in their environment; however, our understanding of how organisms cope with this variation is under-developed. For example, in organisms with temperature-dependent sex determination (TSD), an inability to predict sex ratios under fluctuating incubation temperatures in the field hinders predictions of how species with TSD will fare in a changing climate. To better understand how sex determination is affected by thermal variation, we incubated Trachemys scripta eggs using a "heat wave" design, where embryos experienced a male-producing temperature of 25 ± 3°C for the majority of development and varying durations at a female-producing temperature of 29.5 ± 3°C during the window of development when sex is determined. We compared the sex ratios from these incubation conditions with a previous data set that utilized a similar heat wave design, but instead incubated eggs at a male-producing temperature of 27 ± 3°C but utilized the same female-producing temperature of 29.5 ± 3°C. We compared the sex ratio reaction norms produced from these two incubation conditions and found that, despite differences in average temperatures, both conditions produced 50:50 sex ratios after ∼8 days of exposure to female-producing conditions. This emphasizes that sex can be determined in just a few days at female-producing conditions and that sex determination is relatively unaffected by temperatures outside of this short window. Further, these data demonstrate the reduced accuracy of the constant temperature equivalent model (the leading method of predicting sex ratios) under thermally variable temperatures. Conceptualizing sex determination as the number of days spent incubating at female-producing conditions rather than an aggregate statistic is supported by the mechanistic underpinnings of TSD, helps to improve sex ratio estimation methods, and has important consequences for predicting how species with TSD will fare in a changing climate.
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Affiliation(s)
- A W Carter
- Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - R T Paitz
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
| | - R M Bowden
- School of Biological Sciences, Illinois State University, Normal, IL 61790, USA
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25
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Castelli MA, Whiteley SL, Georges A, Holleley CE. Cellular calcium and redox regulation: the mediator of vertebrate environmental sex determination? Biol Rev Camb Philos Soc 2020; 95:680-695. [DOI: 10.1111/brv.12582] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 01/08/2020] [Accepted: 01/13/2020] [Indexed: 12/16/2022]
Affiliation(s)
- Meghan A. Castelli
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Sarah L. Whiteley
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Arthur Georges
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
| | - Clare E. Holleley
- CSIROAustralian National Wildlife Collection, GPO Box 1700 Canberra 2601 Australia
- Institute for Applied EcologyUniversity of Canberra Canberra 2617 Australia
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26
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Cauret CMS, Gansauge MT, Tupper AS, Furman BLS, Knytl M, Song XY, Greenbaum E, Meyer M, Evans BJ. Developmental Systems Drift and the Drivers of Sex Chromosome Evolution. Mol Biol Evol 2019; 37:799-810. [DOI: 10.1093/molbev/msz268] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
AbstractPhenotypic invariance—the outcome of purifying selection—is a hallmark of biological importance. However, invariant phenotypes might be controlled by diverged genetic systems in different species. Here, we explore how an important and invariant phenotype—the development of sexually differentiated individuals—is controlled in over two dozen species in the frog family Pipidae. We uncovered evidence in different species for 1) an ancestral W chromosome that is not found in many females and is found in some males, 2) independent losses and 3) autosomal segregation of this W chromosome, 4) changes in male versus female heterogamy, and 5) substantial variation among species in recombination suppression on sex chromosomes. We further provide evidence of, and evolutionary context for, the origins of at least seven distinct systems for regulating sex determination among three closely related genera. These systems are distinct in their genomic locations, evolutionary origins, and/or male versus female heterogamy. Our findings demonstrate that the developmental control of sexual differentiation changed via loss, sidelining, and empowerment of a mechanistically influential gene, and offer insights into novel factors that impinge on the diverse evolutionary fates of sex chromosomes.
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Affiliation(s)
| | - Marie-Theres Gansauge
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Andrew S Tupper
- Origins Institute and Department of Biochemistry and Biomedical Science, McMaster University, Hamilton, Canada
| | - Benjamin L S Furman
- Biology Department, McMaster University, Hamilton, Canada
- Department of Zoology, Biodiversity Research Centre, University of British Columbia, Vancouver, Canada
| | - Martin Knytl
- Biology Department, McMaster University, Hamilton, Canada
- Department of Cell Biology, Charles University, Prague 2, Czech Republic
| | - Xue-Ying Song
- Biology Department, McMaster University, Hamilton, Canada
| | - Eli Greenbaum
- Department of Biological Sciences, The University of Texas at El Paso, El Paso, TX
| | - Matthias Meyer
- Department of Evolutionary Genetics, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
| | - Ben J Evans
- Biology Department, McMaster University, Hamilton, Canada
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27
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Abstract
Climate change is occurring at an unprecedented rate and has begun to modify the distribution and phenology of organisms worldwide. Chelonians are expected to be particularly vulnerable due to limited dispersal capabilities as well as widespread temperature-dependent sex determination. The number of papers published about the effects of climate change on turtles has increased exponentially over the last decade; here, I review the data from peer-reviewed publications to assess the likely impacts of climate change on individuals, populations, and communities. Based upon these studies future research should focus on: (1) Individual responses to climate change, particularly with respect to thermal biology, phenology, and microhabitat selection; (2) improving species distribution models by incorporating fine-scale environmental variables as well as physiological processes; (3) identifying the consequences of skewed sex ratios; and (4) assessments of community resilience and the development of methods to mitigate climate change impacts. Although detailed management recommendations are not possible at this point, careful consideration should be given regarding how to manage low vagility species as habitats shift poleward. In the worst-case scenario, proactive management may be required in order to ensure that widespread losses do not occur.
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28
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Carter AL, Bodensteiner BL, Iverson JB, Milne‐Zelman CL, Mitchell TS, Refsnider JM, Warner DA, Janzen FJ. Breadth of the thermal response captures individual and geographic variation in temperature‐dependent sex determination. Funct Ecol 2019. [DOI: 10.1111/1365-2435.13410] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Anna L. Carter
- Department of Ecology, Evolution & Organismal Biology Iowa State University Ames IA USA
| | | | | | | | - Timothy S. Mitchell
- Department of Ecology, Evolution & Behavior University of Minnesota Minneapolis MN USA
| | | | - Daniel A. Warner
- Department of Biological Sciences Auburn University Auburn AL USA
| | - Fredric J. Janzen
- Department of Ecology, Evolution & Organismal Biology Iowa State University Ames IA USA
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29
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The Embryos of Turtles Can Influence Their Own Sexual Destinies. Curr Biol 2019; 29:2597-2603.e4. [PMID: 31378606 DOI: 10.1016/j.cub.2019.06.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Revised: 05/20/2019] [Accepted: 06/12/2019] [Indexed: 11/21/2022]
Abstract
Sessile organisms with thermally sensitive developmental trajectories are at high risk from climate change. For example, oviparous reptiles with temperature-dependent sex determination (TSD) may experience strong (potentially disastrous) shifts in offspring sex ratio if reproducing females are unable to predict incubation conditions at the time of oviposition. How then have TSD reptile taxa persisted over previous periods of extreme climatic conditions? An ability of embryos to move within the egg to select optimal thermal regimes could buffer ambient extremes, but the feasibility of behavioral thermoregulation by embryos has come under strong challenge. To test this idea, we measured thermal gradients within eggs in semi-natural nests of a freshwater turtle species with TSD, manipulated embryonic thermoregulatory ability, and modeled the effects of embryonic thermoregulation on offspring sex ratios. Behavioral thermoregulation by embryos accelerated development and influenced offspring sex ratio, expanding the range of ambient conditions under which nests produce equal numbers of male and female offspring. Model projections suggest that sex ratio shifts induced by global warming will be buffered by the ability of embryos to influence their sexual destiny via behavioral thermoregulation.
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Gallardo-Alvárez MI, Lesher-Gordillo JM, Machkour-M’Rabet S, Zenteno-Ruiz CE, Olivera-Gómez LD, Barragán-Vázquez MDR, Ríos-Rodas L, Valdés-Marín A, Vázquez-López HG, Arriaga-Weiss SL. Genetic diversity and population structure of founders from wildlife conservation management units and wild populations of critically endangered Dermatemys mawii. Glob Ecol Conserv 2019. [DOI: 10.1016/j.gecco.2019.e00616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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Janzen FJ, Delaney DM, Mitchell TS, Warner DA. Do Covariances Between Maternal Behavior and Embryonic Physiology Drive Sex-Ratio Evolution Under Environmental Sex Determination? J Hered 2019; 110:411-421. [PMID: 30982894 DOI: 10.1093/jhered/esz021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 04/11/2019] [Indexed: 11/12/2022] Open
Abstract
Fisherian sex-ratio theory predicts sexual species should have a balanced primary sex ratio. However, organisms with environmental sex determination (ESD) are particularly vulnerable to experiencing skewed sex ratios when environmental conditions vary. Theoretical work has modeled sex-ratio dynamics for animals with ESD with regard to 2 traits predicted to be responsive to sex-ratio selection: 1) maternal oviposition behavior and 2) sensitivity of embryonic sex determination to environmental conditions, and much research has since focused on how these traits influence offspring sex ratios. However, relatively few studies have provided estimates of univariate quantitative genetic parameters for these 2 traits, and the existence of phenotypic or genetic covariances among these traits has not been assessed. Here, we leverage studies on 3 species of reptiles (2 turtle species and a lizard) with temperature-dependent sex determination (TSD) to assess phenotypic covariances between measures of maternal oviposition behavior and thermal sensitivity of the sex-determining pathway. These studies quantified maternal behaviors that relate to nest temperature and sex ratio of offspring incubated under controlled conditions. A positive covariance between these traits would enhance the efficiency of sex-ratio selection when primary sex ratio is unbalanced. However, we detected no such covariance between measures of these categories of traits in the 3 study species. These results suggest that maternal oviposition behavior and thermal sensitivity of sex determination in embryos might evolve independently. Such information is critical to understand how animals with TSD will respond to rapidly changing environments that induce sex-ratio selection.
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Affiliation(s)
- Fredric J Janzen
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA
| | - David M Delaney
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, IA
| | - Timothy S Mitchell
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, MN
| | - Daniel A Warner
- Department of Biological Sciences, Auburn University, Auburn, AL
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Bodensteiner BL, Warner DA, Iverson JB, Milne‐Zelman CL, Mitchell TS, Refsnider JM, Janzen FJ. Geographic variation in thermal sensitivity of early life traits in a widespread reptile. Ecol Evol 2019; 9:2791-2802. [PMID: 30891217 PMCID: PMC6405489 DOI: 10.1002/ece3.4956] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 11/13/2018] [Accepted: 11/25/2018] [Indexed: 01/19/2023] Open
Abstract
Taxa with large geographic distributions generally encompass diverse macroclimatic conditions, potentially requiring local adaptation and/or phenotypic plasticity to match their phenotypes to differing environments. These eco-evolutionary processes are of particular interest in organisms with traits that are directly affected by temperature, such as embryonic development in oviparous ectotherms. Here we examine the spatial distribution of fitness-related early life phenotypes across the range of a widespread vertebrate, the painted turtle (Chrysemys picta). We quantified embryonic and hatchling traits from seven locations (in Idaho, Minnesota, Oregon, Illinois, Nebraska, Kansas, and New Mexico) after incubating eggs under constant conditions across a series of environmentally relevant temperatures. Thermal reaction norms for incubation duration and hatchling mass varied among locations under this common-garden experiment, indicating genetic differentiation or pre-ovulatory maternal effects. However, latitude, a commonly used proxy for geographic variation, was not a strong predictor of these geographic differences. Our findings suggest that this macroclimatic proxy may be an unreliable surrogate for microclimatic conditions experienced locally in nests. Instead, complex interactions between abiotic and biotic factors likely drive among-population phenotypic variation in this system. Understanding spatial variation in key life-history traits provides an important perspective on adaptation to contemporary and future climatic conditions.
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Affiliation(s)
- Brooke L. Bodensteiner
- Department of Ecology Evolution and Organismal BiologyIowa State UniversityAmesIowa
- Department of Biological SciencesVirginia Polytechnic Institute and State UniversityBlacksburgVirginia
| | | | | | | | - Timothy S. Mitchell
- Department of Ecology Evolution and BehaviorUniversity of MinnesotaSaint PaulMinnesota
| | | | - Fredric J. Janzen
- Department of Ecology Evolution and Organismal BiologyIowa State UniversityAmesIowa
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Bókony V, Milne G, Pipoly I, Székely T, Liker A. Sex ratios and bimaturism differ between temperature-dependent and genetic sex-determination systems in reptiles. BMC Evol Biol 2019; 19:57. [PMID: 30777013 PMCID: PMC6378719 DOI: 10.1186/s12862-019-1386-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 02/12/2019] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Sex-determining systems may profoundly influence the ecology, behaviour and demography of animals, yet these relationships are poorly understood. Here we investigate whether species with temperature-dependent (TSD) and genetic sex determination (GSD) differ in key demographic traits, using data from 181 species representing all major phylogenetic lineages of extant reptiles. RESULTS We show that species with TSD exhibit significantly higher within-species variance in sex ratios than GSD species in three major life stages: birth or hatching, juvenility and adulthood. In contrast, sex differences in adult mortality rates do not differ between GSD and TSD species. However, TSD species exhibit significantly greater sex differences in maturation ages than GSD species. CONCLUSION These results support the recent theoretical model that evolution of TSD is facilitated by sex-specific fitness benefits of developmental temperatures due to bimaturism. Our findings suggest that different sex-determination systems are associated with different demographic characteristics that may influence population viability and social evolution.
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Affiliation(s)
- Veronika Bókony
- Lendület Evolutionary Ecology Research Group, Plant Protection Institute, Centre for Agricultural Research, Hungarian Academy of Sciences, Herman Ottó út 15, Budapest, 1022 Hungary
| | - Gregory Milne
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
| | - Ivett Pipoly
- MTA-PE Evolutionary Ecology Research Group, University of Pannonia, Pf. 158, Veszprém, 8201 Hungary
| | - Tamás Székely
- Milner Centre for Evolution, Department of Biology and Biochemistry, University of Bath, Bath, BA2 7AY UK
- Department of Evolutionary Zoology, University of Debrecen, Egyetem tér 1, Debrecen, 4032 Hungary
| | - András Liker
- MTA-PE Evolutionary Ecology Research Group, University of Pannonia, Pf. 158, Veszprém, 8201 Hungary
- Department of Limnology, University of Pannonia, Pf. 158, Veszprém, 8201 Hungary
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Developmental asynchrony and antagonism of sex determination pathways in a lizard with temperature-induced sex reversal. Sci Rep 2018; 8:14892. [PMID: 30291276 PMCID: PMC6173690 DOI: 10.1038/s41598-018-33170-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/19/2018] [Indexed: 12/22/2022] Open
Abstract
Vertebrate sex differentiation follows a conserved suite of developmental events: the bipotential gonads differentiate and shortly thereafter sex specific traits become dimorphic. However, this may not apply to squamates, a diverse vertebrate lineage comprising of many species with thermosensitive sexual development. Of the three species with data on the relative timing of gonad differentiation and genital dimorphism, the females of two (Niveoscincus ocellatus and Barisia imbricata) exhibit a phase of temporary pseudohermaphroditism or TPH (gonads have differentiated well before genital dimorphism). We report a third example of TPH in Pogona vitticeps, an agamid with temperature-induced male to female sex reversal. These findings suggest that for female squamates, genital and gonad development may not be closely synchronised, so that TPH may be common. We further observed a high frequency of ovotestes, a usually rare gonadal phenotype characterised by a mix of male and female structures, exclusively associated with temperature-induced sex reversal. We propose that ovotestes are evidence of a period of antagonism between male and female sex-determining pathways during sex reversal. Female sexual development in squamates is considerably more complex than has been appreciated, providing numerous avenues for future exploration of the genetic and hormonal cues that govern sexual development.
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Bowne DR, Cosentino BJ, Anderson LJ, Bloch CP, Cooke S, Crumrine PW, Dallas J, Doran A, Dosch JJ, Druckenbrod DL, Durtsche RD, Garneau D, Genet KS, Fredericksen TS, Kish PA, Kolozsvary MB, Kuserk FT, Lindquist ES, Mankiewicz C, March JG, Muir TJ, Murray KG, Santulli MN, Sicignano FJ, Smallwood PD, Urban RA, Winnett-Murray K, Zimmermann CR. Effects of urbanization on the population structure of freshwater turtles across the United States. CONSERVATION BIOLOGY : THE JOURNAL OF THE SOCIETY FOR CONSERVATION BIOLOGY 2018; 32:1150-1161. [PMID: 29781169 DOI: 10.1111/cobi.13136] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 04/12/2018] [Accepted: 04/26/2018] [Indexed: 06/08/2023]
Abstract
Landscape-scale alterations that accompany urbanization may negatively affect the population structure of wildlife species such as freshwater turtles. Changes to nesting sites and higher mortality rates due to vehicular collisions and increased predator populations may particularly affect immature turtles and mature female turtles. We hypothesized that the proportions of adult female and immature turtles in a population will negatively correlate with landscape urbanization. As a collaborative effort of the Ecological Research as Education Network (EREN), we sampled freshwater turtle populations in 11 states across the central and eastern United States. Contrary to expectations, we found a significant positive relationship between proportions of mature female painted turtles (Chrysemys picta) and urbanization. We did not detect a relationship between urbanization and proportions of immature turtles. Urbanization may alter the thermal environment of nesting sites such that more females are produced as urbanization increases. Our approach of creating a collaborative network of scientists and students at undergraduate institutions proved valuable in terms of testing our hypothesis over a large spatial scale while also allowing students to gain hands-on experience in conservation science.
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Affiliation(s)
- David R Bowne
- Department of Biology, Elizabethtown College, One Alpha Drive, Elizabethtown, PA 17022, U.S.A
| | - Bradley J Cosentino
- Department of Biology, Hobart and William Smith Colleges, 113 Eaton Hall, Geneva, NY 14456, U.S.A
| | - Laurel J Anderson
- Department of Botany & Microbiology, Ohio Wesleyan University, 61 S. Sandusky Street, Delaware, OH 43015, U.S.A
| | - Christopher P Bloch
- Department of Biological Sciences, Bridgewater State University, 131 Summer Street, Bridgewater, MA 02325, U.S.A
| | - Sandra Cooke
- Department of Biology, High Point University, One University Parkway, High Point, NC 27268, U.S.A
| | - Patrick W Crumrine
- Geography, Planning, and Sustainability, and Biological Sciences, Rowan University, 201 Mullica Hill Road, Glassboro, NJ 08090, U.S.A
| | - Jason Dallas
- Geological, Environmental, and Marine Sciences, Rider University, 2083 Lawrenceville Road, Lawrenceville, NJ 08648, U.S.A
- Current address: Department of Biology, Shippensburg University, 1871 Old Main Drive, Shippensburg, PA 17257, U.S.A
| | - Alexandra Doran
- Department of Biology, Elizabethtown College, One Alpha Drive, Elizabethtown, PA 17022, U.S.A
- Current address: Management Systems & Compliance Support, Environmental Resources Management, 75 Valley Stream Parkway, Suite 200, Malvern, PA 19355, U.S.A
| | - Jerald J Dosch
- Biology Department, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105, U.S.A
| | - Daniel L Druckenbrod
- Geological, Environmental, and Marine Sciences, Rider University, 2083 Lawrenceville Road, Lawrenceville, NJ 08648, U.S.A
| | - Richard D Durtsche
- Department of Biological Sciences, Northern Kentucky University, 148 Science Center, Nunn Drive, Highland Heights, KY 41099, U.S.A
| | - Danielle Garneau
- Center for Earth and Environmental Science, State University of New York, Plattsburgh, 101 Broad Street, Plattsburgh, NY 12901, U.S.A
| | - Kristen S Genet
- Department of Biology, Anoka-Ramsey Community College, 11200 Mississippi Boulevard NW, Coon Rapids, MN 55433, U.S.A
| | - Todd S Fredericksen
- School of Natural Sciences and Mathematics, Ferrum College, P.O. Box 100, Ferrum, VA 24088, U.S.A
| | - Peter A Kish
- Biology, Moravian Academy, 4313 Green Pond Road, Bethlehem, PA 18017, U.S.A
| | - Mary Beth Kolozsvary
- Department of Environmental Studies and Sciences, Siena College, 515 Loudon Road, Loudonville, NY 12211, U.S.A
| | - Frank T Kuserk
- Department of Biological Sciences, Moravian College, 1200 Main Street, Bethlehem, PA 18018, U.S.A
| | - Erin S Lindquist
- Department of Biological Sciences, Meredith College, 3800 Hillsborough Street, Raleigh, NC 27607, U.S.A
| | - Carol Mankiewicz
- Department of Biology, Beloit College, 700 College Street, Beloit, WI 53511, U.S.A
| | - James G March
- Biology Department, Washington & Jefferson College, 60 S. Lincoln Street, Washington, PA 15301, U.S.A
| | - Timothy J Muir
- Department of Biology, Augustana College, 639 38th Street, Rock Island, IL 61201, U.S.A
| | - K Greg Murray
- Department of Biology, Hope College, 35 E. 12th Street, Holland, MI 49423, U.S.A
| | - Madeline N Santulli
- Department of Environmental Studies and Sciences, Siena College, 515 Loudon Road, Loudonville, NY 12211, U.S.A
| | - Frank J Sicignano
- Department of Environmental Studies and Sciences, Siena College, 515 Loudon Road, Loudonville, NY 12211, U.S.A
- San Francisco Recreation and Parks Department, City and County of San Francisco, 501 Stanyan Street, San Francisco, CA 94117, U.S.A
| | - Peter D Smallwood
- Department of Biology, University of Richmond, 28 Westhampton Way, Richmond, VA 23173, U.S.A
| | - Rebecca A Urban
- Biology Department, Lebanon Valley College, 101 N. College Avenue, Annville, PA 17033, U.S.A
| | - Kathy Winnett-Murray
- Department of Biology, Hope College, 35 E. 12th Street, Holland, MI 49423, U.S.A
| | - Craig R Zimmermann
- Department of Biology, Rogers State University, 1701 W. Will Rogers Boulevard, Claremore, OK 74017, U.S.A
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Nelson NJ, Keall SN, Refsnider JM, Carter AL. Behavioral variation in nesting phenology may offset sex-ratio bias in tuatara. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 329:373-381. [PMID: 29939491 DOI: 10.1002/jez.2196] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 05/03/2018] [Accepted: 05/30/2018] [Indexed: 11/08/2022]
Abstract
The nest environment for eggs of reptiles has lifelong implications for offspring performance and success, and, ultimately, for population viability and species distributions. However, understanding the various abiotic and biotic drivers of nesting is complex, particularly regarding variation in nesting behavior of females and consequences for sex ratios in species with temperature-dependent sex determination (TSD). We investigated how nest construction and nesting phenology affect the incubation environment of a reptile with TSD, the tuatara (Sphenodon punctatus), a species that is at risk from climate-mediated male bias in population sex ratios. Using longitudinal behavioral data, we addressed the following questions. (1) Does nesting behavior vary with seasonal or location cues? (2) Does variation in nesting phenology or nest construction affect the incubation environment? We aimed to investigate whether female tuatara could modify nesting behavior to respond to novel environments, including a warming climate, allowing for successful incubation and balanced population sex ratios, maintaining population viability throughout their historic range. We predicted that earlier nesting after warm winters increased the likelihood that females will be produced, despite the sex determining system where males are produced from warmer temperatures. Further research is needed to understand the extent to which nesting behavior varies by individual through time, and across the range of tuatara, and the importance of habitat variability in maintaining production of females under future climate warming.
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Affiliation(s)
- Nicola J Nelson
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Susan N Keall
- School of Biological Sciences, Victoria University of Wellington, Wellington, New Zealand
| | | | - Anna L Carter
- Department of Ecology, Evolution & Organismal Biology, Iowa State University, Ames, Indiana
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Janzen FJ, Hoekstra LA, Brooks RJ, Carroll DM, Gibbons JW, Greene JL, Iverson JB, Litzgus JD, Michael ED, Parren SG, Roosenburg WM, Strain GF, Tucker JK, Ultsch GR. Altered spring phenology of North American freshwater turtles and the importance of representative populations. Ecol Evol 2018; 8:5815-5827. [PMID: 29938095 PMCID: PMC6010881 DOI: 10.1002/ece3.4120] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Revised: 03/22/2018] [Accepted: 03/29/2018] [Indexed: 12/25/2022] Open
Abstract
Globally, populations of diverse taxa have altered phenology in response to climate change. However, most research has focused on a single population of a given taxon, which may be unrepresentative for comparative analyses, and few long-term studies of phenology in ectothermic amniotes have been published. We test for climate-altered phenology using long-term studies (10-36 years) of nesting behavior in 14 populations representing six genera of freshwater turtles (Chelydra, Chrysemys, Kinosternon, Malaclemys, Sternotherus, and Trachemys). Nesting season initiation occurs earlier in more recent years, with 11 of the populations advancing phenology. The onset of nesting for nearly all populations correlated well with temperatures during the month preceding nesting. Still, certain populations of some species have not advanced phenology as might be expected from global patterns of climate change. This collection of findings suggests a proximate link between local climate and reproduction that is potentially caused by variation in spring emergence from hibernation, ability to process food, and thermoregulatory opportunities prior to nesting. However, even though all species had populations with at least some evidence of phenological advancement, geographic variation in phenology within and among turtle species underscores the critical importance of representative data for accurate comprehensive assessments of the biotic impacts of climate change.
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Affiliation(s)
- Fredric J. Janzen
- Department of Ecology, Evolution & Organismal BiologyIowa State UniversityAmesIowa
| | - Luke A. Hoekstra
- Department of Ecology, Evolution & Organismal BiologyIowa State UniversityAmesIowa
| | - Ronald J. Brooks
- Department of Integrative BiologyUniversity of GuelphGuelphONCanada
| | | | | | | | | | | | - Edwin D. Michael
- Division of Forestry and Natural ResourcesWest Virginia UniversityMorgantownWest Virginia
| | | | | | | | - John K. Tucker
- Jerry F. Costello National Great Rivers Research and Education Center Confluence Field StationEast AltonIllinois
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Refsnider JM, Qian SS, Streby HM, Carter SE, Clifton IT, Siefker AD, Vazquez TK. Reciprocally transplanted lizards along an elevational gradient match light environment use of local lizards via phenotypic plasticity. Funct Ecol 2018. [DOI: 10.1111/1365-2435.13071] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Song S. Qian
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
| | - Henry M. Streby
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
| | - Sarah E. Carter
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
| | - Ian T. Clifton
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
| | - Adam D. Siefker
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
| | - Tyara K. Vazquez
- Department of Environmental SciencesUniversity of Toledo Toledo OH USA
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Warner DA, Mitchell TS, Bodensteiner BL, Janzen FJ. The effect of hormone manipulations on sex ratios varies with environmental conditions in a turtle with temperature-dependent sex determination. JOURNAL OF EXPERIMENTAL ZOOLOGY PART 2018; 327:172-181. [PMID: 29356364 DOI: 10.1002/jez.2085] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2017] [Accepted: 06/27/2017] [Indexed: 02/03/2023]
Abstract
Exogenous application of steroids and related substances to eggs affects offspring sex ratios in species with temperature-dependent sex determination (TSD). Laboratory studies demonstrate that this effect is most pronounced near the constant temperature that produces 1:1 sex ratios (i.e., pivotal temperature). However, the impact of such chemicals on sex determination under natural nest temperatures (which fluctuate daily) is unknown, but could provide insight into the relative contributions of these two factors under natural conditions. We applied estradiol (E2) and an aromatase inhibitor (fadrozole) to eggs of the painted turtle (Chrysemys picta), a species with TSD, and allowed eggs to incubate under natural conditions during two field seasons (in 2012 and 2013). Exogenous E2, fadrozole, and nest temperature contributed to variation in offspring sex ratio, but the relative contributions of these factors differed between years. In 2012, a much hotter than average season, sex ratios were heavily female biased regardless of nest temperature and chemical treatment. However, in 2013, a milder season, both nest temperature and chemical treatment were important. Moreover, a significant interaction between nest temperature and treatment demonstrated that exogenous estradiol induces female development regardless of nest temperature, but aromatase inhibition widens the range of temperatures that produces both sexes.
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Affiliation(s)
- Daniel A Warner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa.,Department of Biological Sciences, Auburn University, Auburn, Alabama
| | - Timothy S Mitchell
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa.,Department of Biological Sciences, Auburn University, Auburn, Alabama
| | - Brooke L Bodensteiner
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa
| | - Fredric J Janzen
- Department of Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa
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Environmental Warming and Feminization of One of the Largest Sea Turtle Populations in the World. Curr Biol 2018; 28:154-159.e4. [DOI: 10.1016/j.cub.2017.11.057] [Citation(s) in RCA: 160] [Impact Index Per Article: 26.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2017] [Revised: 11/10/2017] [Accepted: 11/22/2017] [Indexed: 11/23/2022]
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Carter AW, Bowden RM, Paitz RT. Seasonal shifts in sex ratios are mediated by maternal effects and fluctuating incubation temperatures. Funct Ecol 2017; 31:876-884. [PMID: 28584392 PMCID: PMC5456293 DOI: 10.1111/1365-2435.12801] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Sex-specific maternal effects can be adaptive sources of phenotypic plasticity. Reptiles with temperature-dependent sex determination (TSD) are a powerful system to investigate such maternal effects because offspring phenotype, including sex, can be sensitive to maternal influences such as oestrogens and incubation temperatures.In red-eared slider turtles (Trachemys scripta), concentrations of maternally derived oestrogens and incubation temperatures increase across the nesting season; we wanted to determine if sex ratios shift in a seasonally concordant manner, creating the potential for sex-specific maternal effects, and to define the sex ratio reaction norms under fluctuating temperatures across the nesting season.Eggs from early and late season clutches were incubated under a range of thermally fluctuating temperatures, maternally derived oestradiol concentrations were quantified via radioimmunoassay, and hatchling sex was identified. We found that late season eggs had higher maternal oestrogen concentrations and were more likely to produce female hatchlings. The sex ratio reaction norm curves systematically varied with season, such that with even a slight increase in temperature (0.5°C), late season eggs produced up to 49% more females than early season eggs.We found a seasonal shift in sex ratios which creates the potential for sex-specific phenotypic matches across the nesting season driven by maternal effects. We also describe, for the first time, systematic variation in the sex ratio reaction norm curve within a single population in a species with TSD.
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Affiliation(s)
- Amanda W. Carter
- School of Biological Sciences, Illinois State University, Normal, IL, United States
| | - Rachel M. Bowden
- School of Biological Sciences, Illinois State University, Normal, IL, United States
| | - Ryan T. Paitz
- School of Biological Sciences, Illinois State University, Normal, IL, United States
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Rosenfeld CS, Denslow ND, Orlando EF, Gutierrez-Villagomez JM, Trudeau VL. Neuroendocrine disruption of organizational and activational hormone programming in poikilothermic vertebrates. JOURNAL OF TOXICOLOGY AND ENVIRONMENTAL HEALTH. PART B, CRITICAL REVIEWS 2017; 20:276-304. [PMID: 28895797 PMCID: PMC6174081 DOI: 10.1080/10937404.2017.1370083] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In vertebrates, sexual differentiation of the reproductive system and brain is tightly orchestrated by organizational and activational effects of endogenous hormones. In mammals and birds, the organizational period is typified by a surge of sex hormones during differentiation of specific neural circuits; whereas activational effects are dependent upon later increases in these same hormones at sexual maturation. Depending on the reproductive organ or brain region, initial programming events may be modulated by androgens or require conversion of androgens to estrogens. The prevailing notion based upon findings in mammalian models is that male brain is sculpted to undergo masculinization and defeminization. In absence of these responses, the female brain develops. While timing of organizational and activational events vary across taxa, there are shared features. Further, exposure of different animal models to environmental chemicals such as xenoestrogens such as bisphenol A-BPA and ethinylestradiol-EE2, gestagens, and thyroid hormone disruptors, broadly classified as neuroendocrine disrupting chemicals (NED), during these critical periods may result in similar alterations in brain structure, function, and consequently, behaviors. Organizational effects of neuroendocrine systems in mammals and birds appear to be permanent, whereas teleost fish neuroendocrine systems exhibit plasticity. While there are fewer NED studies in amphibians and reptiles, data suggest that NED disrupt normal organizational-activational effects of endogenous hormones, although it remains to be determined if these disturbances are reversible. The aim of this review is to examine how various environmental chemicals may interrupt normal organizational and activational events in poikilothermic vertebrates. By altering such processes, these chemicals may affect reproductive health of an animal and result in compromised populations and ecosystem-level effects.
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Affiliation(s)
- Cheryl S. Rosenfeld
- Department of Biomedical Sciences, University of Missouri, Columbia, MO, USA
- Thompson Center for Autism and Neurobehavioral Disorders, Columbia, MO, USA
- Bond Life Sciences Center, University of Missouri, Columbia, MO, USA
| | - Nancy D. Denslow
- Department of Physiological Sciences, University of Florida, Gainesville, FL, USA
- Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, USA
| | - Edward F. Orlando
- Department of Animal and Avian Sciences, University of Maryland, College Park, MD, USA
| | | | - Vance L. Trudeau
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
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