1
|
Versluijs TSL, Zhemchuzhnikov MK, Kutcherov D, Roslin T, Martin Schmidt N, van Gils JA, Reneerkens J. Site-specific length-biomass relationships of arctic arthropod families are critical for accurate ecological inferences. PeerJ 2023; 11:e15943. [PMID: 37692121 PMCID: PMC10492534 DOI: 10.7717/peerj.15943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/31/2023] [Indexed: 09/12/2023] Open
Abstract
Arthropods play a crucial role in terrestrial ecosystems, for instance in mediating energy fluxes and in forming the food base for many organisms. To better understand their functional role in such ecosystem processes, monitoring of trends in arthropod biomass is essential. Obtaining direct measurements of the body mass of individual specimens is laborious. Therefore, these data are often indirectly acquired by utilizing allometric length-biomass relationships based on a correlative parameter, such as body length. Previous studies have often used such relationships with a low taxonomic resolution and/or small sample size and/or adopted regressions calibrated in different biomes. Despite the scientific interest in the ecology of arctic arthropods, no site-specific family-level length-biomass relationships have hitherto been published. Here we present 27 family-specific length-biomass relationships from two sites in the High Arctic: Zackenberg in northeast Greenland and Knipovich in north Taimyr, Russia. We show that length-biomass regressions from different sites within the same biome did not affect estimates of phenology but did result in substantially different estimates of arthropod biomass. Estimates of daily biomass at Zackenberg were on average 24% higher when calculated using regressions for Knipovich compared to using regressions for Zackenberg. In addition, calculations of daily arthropod biomass at Zackenberg based on order-level regressions from frequently cited studies in literature revealed overestimations of arthropod biomass ranging from 69.7% to 130% compared to estimates based on regressions for Zackenberg. Our results illustrate that the use of allometric relationships from different sites can significantly alter the biological interpretation of, for instance, the interaction between insectivorous birds and their arthropod prey. We conclude that length-biomass relationships should be locally established rather than being based on global relationships.
Collapse
Affiliation(s)
- Tom S. L. Versluijs
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Texel, The Netherlands
- Faculty of Science and Engineering, University of Groningen, Groningen, The Netherlands
| | - Mikhail K. Zhemchuzhnikov
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Texel, The Netherlands
- Faculty of Science and Engineering, University of Groningen, Groningen, The Netherlands
| | - Dmitry Kutcherov
- Department of Entomology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Tomas Roslin
- Department of Ecology, Swedish University of Agricultural Sciences (SLU), Uppsala, Sweden
| | - Niels Martin Schmidt
- Department of Ecoscience, Aarhus University, Roskilde, Denmark
- Arctic Research Centre, Aarhus University, Aarhus, Denmark
| | - Jan A. van Gils
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Texel, The Netherlands
- Faculty of Science and Engineering, University of Groningen, Groningen, The Netherlands
| | - Jeroen Reneerkens
- Department of Coastal Systems, NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Texel, The Netherlands
| |
Collapse
|
2
|
A Revision of the Traditional Analysis Method of Allometry to Allow Extension of the Normality-Borne Complexity of Error Structure: Examining the Adequacy of a Normal-Mixture Distribution-Driven Error Term. BIOMED RESEARCH INTERNATIONAL 2022; 2022:8310213. [PMID: 36172489 PMCID: PMC9512611 DOI: 10.1155/2022/8310213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 08/23/2022] [Accepted: 08/25/2022] [Indexed: 11/17/2022]
Abstract
Huxley’s model of simple allometry provides a parsimonious scheme for examining scaling relationships in scientific research, resource management, and species conservation endeavors. Factors including biological error, analysis method, sample size, and overall data quality can undermine the reliability of a fit of Huxley’s model. Customary amendments enhance the complexity of the power function-conveyed systematic term while keeping the usual normality-borne error structure. The resulting protocols bear multiple-parameter complex allometry forms that could pose interpretative shortcomings and parameter estimation difficulties, and even being empirically pertinent, they could potentially bear overfitting. A subsequent heavy-tailed Q-Q normal spread often remains undetected since the adequacy of a normally distributed error term remains unexplored. Previously, we promoted the advantages of keeping Huxley’s model-driven systematic part while switching to a logistically distributed error term to improve fit quality. Here, we analyzed eelgrass leaf biomass and area data exhibiting a marked size-related heterogeneity, perhaps explaining a lack of systematization at data gathering. Overdispersion precluded adequacy of the logistically adapted protocol, thereby suggesting processing data through a median absolute deviation scheme aimed to remove unduly replicates. Nevertheless, achieving regularity to Huxley’s power function-like trend required the removal of many replicates, thereby questioning the integrity of a data cleaning approach. But, we managed to adapt the complexity of the error term to reliably identify Huxley’s model-like systematic part masked by variability in data. Achieving this relied on an error term conforming to a normal mixture distribution which successfully managed overdispersion in data. Compared to normal-complex allometry and data cleaning composites present arrangement delivered a coherent Q-Q normal mixture spread and a remarkable reproducibility strength of derived proxies. By keeping the analysis within Huxley’s original theory, the present approach enables substantiating nondestructive allometric proxies aimed at eelgrass conservation. The viewpoint endorsed here could also make data cleaning unnecessary.
Collapse
|
3
|
Allometric patterns in phrynosomatid lizards and the implications for reconstructing body size for fossils. Evol Ecol 2022. [DOI: 10.1007/s10682-022-10186-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
4
|
Abstract
The magnitude of many biological traits relates strongly and regularly to body size. Consequently, a major goal of comparative biology is to understand and apply these 'size-scaling' relationships, traditionally quantified by using linear regression analyses based on log-transformed data. However, recently some investigators have questioned this traditional method, arguing that linear or non-linear regression based on untransformed arithmetic data may provide better statistical fits than log-linear analyses. Furthermore, they advocate the replacement of the traditional method by alternative specific methods on a case-by-case basis, based simply on best-fit criteria. Here, I argue that the use of logarithms in scaling analyses presents multiple valuable advantages, both statistical and conceptual. Most importantly, log-transformation allows biologically meaningful, properly scaled (scale-independent) comparisons of organisms of different size, whereas non-scaled (scale-dependent) analyses based on untransformed arithmetic data do not. Additionally, log-based analyses can readily reveal biologically and theoretically relevant discontinuities in scale invariance during developmental or evolutionary increases in body size that are not shown by linear or non-linear arithmetic analyses. In this way, log-transformation advances our understanding of biological scaling conceptually, not just statistically. I hope that my Commentary helps students, non-specialists and other interested readers to understand the general benefits of using log-transformed data in size-scaling analyses, and stimulates advocates of arithmetic analyses to show how they may improve our understanding of scaling conceptually, not just statistically.
Collapse
Affiliation(s)
- Douglas S Glazier
- Department of Biology, Juniata College, 1700 Moore Street, Huntingdon, PA 16652, USA
| |
Collapse
|
5
|
Length-mass relationships for macroinvertebrates in the Choghakhor international wetland, Iran. Biologia (Bratisl) 2021. [DOI: 10.2478/s11756-020-00585-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
6
|
Is Allometric Variation in the Cephalic Horn on Male Rhinoceros Beetles Discontinuously Dimorphic? Evol Biol 2021. [DOI: 10.1007/s11692-021-09533-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
7
|
Packard GC. Allometric growth in mass by the brain of mammals. Anat Rec (Hoboken) 2020; 304:1551-1561. [PMID: 33103327 DOI: 10.1002/ar.24555] [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: 06/23/2020] [Revised: 08/02/2020] [Accepted: 09/21/2020] [Indexed: 11/07/2022]
Abstract
I re-examined published data for ontogenetic change in relative mass of the brain in six species of mammal (i.e., sheep, pig, cow, horse, rat, cat) to illustrate an insidious problem with conventional analyses of brain-body allometry. Graphical displays of logarithmic transformations of the original data for each species give the appearance of two discrete mathematical distributions, but untransformed observations nonetheless conform to a single distribution that is well described by a single, nonlinear equation. The concept of biphasic, allometric growth by the brain consequently is an artifact of transformation. The notion of Rapid and Slow phases in relative growth by the brain also is an artifact, because the notion is based explicitly on the concept of biphasic growth allometry. Relative growth by the brain in sheep, pigs, cows, and horses follows the path of a power curve with an exponent less than 1, so relative growth declines progressively as animals grow to their maximum size, at which point growth effectively ends for both brain and body. Relative growth by the brain in rats and cats follows the path of an exponential curve and consequently is more like relative growth by the brain of odontocoete cetaceans and primates, with the brain growing rapidly relative to the body early in ontogeny and attaining maximum (cats) or near-maximum (rats) mass well before the body reaches its maximum. An exponential pattern of relative growth by the brain appears to have evolved independently in rodents, carnivores, odontocoetes, and primates.
Collapse
Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
8
|
Packard G. Modeling allometric variation: lessons from the metabolic allometry of black carp (Mylopharyngodon piceus). CAN J ZOOL 2019. [DOI: 10.1139/cjz-2019-0092] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
I used linear and nonlinear regression to re-examine published data on the scaling of metabolic rate vs. body mass in an ontogenetic series of black carp (Mylopharyngodon piceus (Richardson, 1846)). My objective was to expose shortcomings of the conventional procedure for fitting statistical models to bivariate observations (i.e., the procedure that is widely attributed to J.S. Huxley) and simultaneously to outline a more general and utilitarian protocol for analyzing bivariate data in studies of allometry. Authors of the original study on carp reported exponents of 0.83 and 0.78 for two-parameter power functions fitted to observations for resting metabolism and maximum metabolism, respectively. However, metabolic scaling in these fishes actually is described best by straight lines having positive intercepts with the Y axis. The allometric exponent is 1 for a straight line, so interpretations from the current analyses differ substantially from those reached in the original investigation. Contemporary theories for the evolution of optimal body size (e.g., the Metabolic Theory of Ecology) are based on patterns of metabolic allometry that have been estimated by the conventional analytical method. Thus, the current investigation raises questions about generally accepted patterns of metabolic allometry and theoretical models based upon them.
Collapse
Affiliation(s)
- G.C. Packard
- Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| |
Collapse
|
9
|
Abstract
Abstract
The concept of biphasic, loglinear growth of the vertebrate brain is based on graphical displays of logarithmic transformations of the original measurements. Such displays commonly give the appearance of two distinct mathematical distributions – one set of observations following a steep trajectory at the low end of the size range and another set following a shallow trajectory at the high end. However, the appearance of two distributions is an artefact resulting from the logarithmic transformations. Observations of brain mass vs. body mass in each of the eight vertebrate species examined in the current investigation conform to a single mathematical distribution that is well described by a single equation fitted to the original, untransformed data by non-linear regression. Data for carp, chickens, kangaroos and rabbits are described by three-parameter power equations whereas those for dolphins and primates are described by exponential functions that rise rapidly to a maximum. The brain continues to grow throughout life in carp, chickens, kangaroos and rabbits but not in dolphins and primates. Future investigations of relative growth of the brain should be based on graphical and analytical study of observations expressed on the native mathematical scale.
Collapse
Affiliation(s)
- Gary C Packard
- Department of Biology, Colorado State University, Fort Collins, CO, USA
| |
Collapse
|
10
|
Tomlinson S. The mathematics of thermal sub-optimality: Nonlinear regression characterization of thermal performance of reptile metabolic rates. J Therm Biol 2019; 81:49-58. [PMID: 30975423 DOI: 10.1016/j.jtherbio.2019.02.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/22/2019] [Accepted: 02/02/2019] [Indexed: 11/20/2022]
Affiliation(s)
- Sean Tomlinson
- School of Molecular and Life Sciences, Curtin University, Kent Street, Bentley 6102, Western Australia, Australia; Kings Park Science, Department of Biodiversity, Conservation and Attractions, Kattidj Close, Kings Park 6005, Western Australia, Australia.
| |
Collapse
|
11
|
Ghedini G, White CR, Marshall DJ. Metabolic scaling across succession: Do individual rates predict community‐level energy use? Funct Ecol 2018. [DOI: 10.1111/1365-2435.13103] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Giulia Ghedini
- Centre for Geometric Biology School of Biological Sciences Monash University Melbourne Vic. Australia
| | - Craig R. White
- Centre for Geometric Biology School of Biological Sciences Monash University Melbourne Vic. Australia
| | - Dustin J. Marshall
- Centre for Geometric Biology School of Biological Sciences Monash University Melbourne Vic. Australia
| |
Collapse
|
12
|
McCabe CM, Nunn CL. Effective Network Size Predicted From Simulations of Pathogen Outbreaks Through Social Networks Provides a Novel Measure of Structure-Standardized Group Size. Front Vet Sci 2018; 5:71. [PMID: 29774217 PMCID: PMC5943561 DOI: 10.3389/fvets.2018.00071] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 03/26/2018] [Indexed: 01/06/2023] Open
Abstract
The transmission of infectious disease through a population is often modeled assuming that interactions occur randomly in groups, with all individuals potentially interacting with all other individuals at an equal rate. However, it is well known that pairs of individuals vary in their degree of contact. Here, we propose a measure to account for such heterogeneity: effective network size (ENS), which refers to the size of a maximally complete network (i.e., unstructured, where all individuals interact with all others equally) that corresponds to the outbreak characteristics of a given heterogeneous, structured network. We simulated susceptible-infected (SI) and susceptible-infected-recovered (SIR) models on maximally complete networks to produce idealized outbreak duration distributions for a disease on a network of a given size. We also simulated the transmission of these same diseases on random structured networks and then used the resulting outbreak duration distributions to predict the ENS for the group or population. We provide the methods to reproduce these analyses in a public R package, "enss." Outbreak durations of simulations on randomly structured networks were more variable than those on complete networks, but tended to have similar mean durations of disease spread. We then applied our novel metric to empirical primate networks taken from the literature and compared the information represented by our ENSs to that by other established social network metrics. In AICc model comparison frameworks, group size and mean distance proved to be the metrics most consistently associated with ENS for SI simulations, while group size, centralization, and modularity were most consistently associated with ENS for SIR simulations. In all cases, ENS was shown to be associated with at least two other independent metrics, supporting its use as a novel metric. Overall, our study provides a proof of concept for simulation-based approaches toward constructing metrics of ENS, while also revealing the conditions under which this approach is most promising.
Collapse
Affiliation(s)
- Collin M. McCabe
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, United States
- Division of Infectious Diseases and Global Health, Department of Medicine, Duke University, Durham, NC, United States
- Department of Evolutionary Anthropology, Duke University, Durham, NC, United States
| | - Charles L. Nunn
- Department of Evolutionary Anthropology, Duke University, Durham, NC, United States
- Triangle Center for Evolutionary Medicine (TriCEM), Durham, NC, United States
| |
Collapse
|
13
|
Packard GC. Is complex allometry in field metabolic rates of mammals a statistical artifact? Comp Biochem Physiol A Mol Integr Physiol 2017; 203:322-327. [DOI: 10.1016/j.cbpa.2016.10.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 10/13/2016] [Accepted: 10/14/2016] [Indexed: 11/25/2022]
|
14
|
Affiliation(s)
- Gary C. Packard
- Department of Biology; Colorado State University; Fort Collins CO 80523-1878 USA
| |
Collapse
|
15
|
Barker JM, Cooper CE, Withers PC, Nicol SC. Reexamining Echidna Physiology: The Big Picture forTachyglossus aculeatus acanthion. Physiol Biochem Zool 2016; 89:169-81. [DOI: 10.1086/686716] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
16
|
Tomlinson S. Novel approaches to the calculation and comparison of thermoregulatory parameters: Non-linear regression of metabolic rate and evaporative water loss in Australian rodents. J Therm Biol 2016; 57:54-65. [DOI: 10.1016/j.jtherbio.2016.01.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2015] [Revised: 01/26/2016] [Accepted: 01/26/2016] [Indexed: 11/29/2022]
|
17
|
Ljungström G, Stjernstedt M, Wapstra E, Olsson M. Selection and constraints on offspring size-number trade-offs in sand lizards (Lacerta agilis). J Evol Biol 2016; 29:979-90. [PMID: 26851437 DOI: 10.1111/jeb.12838] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Revised: 01/25/2016] [Accepted: 01/31/2016] [Indexed: 11/27/2022]
Abstract
The trade-off between offspring size and number is a central component of life-history theory, postulating that larger investment into offspring size inevitably decreases offspring number. This trade-off is generally discussed in terms of genetic, physiological or morphological constraints; however, as among-individual differences can mask individual trade-offs, the underlying mechanisms may be difficult to reveal. In this study, we use multivariate analyses to investigate whether there is a trade-off between offspring size and number in a population of sand lizards by separating among- and within-individual patterns using a 15-year data set collected in the wild. We also explore the ecological and evolutionary causes and consequences of this trade-off by investigating how a female's resource (condition)- vs. age-related size (snout-vent length) influences her investment into offspring size vs. number (OSN), whether these traits are heritable and under selection and whether the OSN trade-off has a genetic component. We found a negative correlation between offspring size and number within individual females and physical constraints (size of body cavity) appear to limit the number of eggs that a female can produce. This suggests that the OSN trade-off occurs due to resource constraints as a female continues to grow throughout life and, thus, produces larger clutches. In contrast to the assumptions of classic OSN theory, we did not detect selection on offspring size; however, there was directional selection for larger clutch sizes. The repeatabilities of both offspring size and number were low and we did not detect any additive genetic variance in either trait. This could be due to strong selection (past or current) on these life-history traits, or to insufficient statistical power to detect significant additive genetic effects. Overall, the findings of this study are an important illustration of how analyses of within-individual patterns can reveal trade-offs and their underlying causes, with potential evolutionary and ecological consequences that are otherwise hidden by among-individual variation.
Collapse
Affiliation(s)
- G Ljungström
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - M Stjernstedt
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden
| | - E Wapstra
- School of Biological Sciences, University of Tasmania, Hobart, Tas., Australia
| | - M Olsson
- Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.,School of Biological Sciences, University of Sydney, Sydney, NSW, Australia
| |
Collapse
|
18
|
Hedrick MS, Hancock TV, Hillman SS. Metabolism at the Max: How Vertebrate Organisms Respond to Physical Activity. Compr Physiol 2015; 5:1677-703. [DOI: 10.1002/cphy.c130032] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
19
|
Tomlinson S, Dixon KW, Didham RK, Bradshaw SD. Physiological plasticity of metabolic rates in the invasive honey bee and an endemic Australian bee species. J Comp Physiol B 2015; 185:835-44. [DOI: 10.1007/s00360-015-0930-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Revised: 08/18/2015] [Accepted: 08/23/2015] [Indexed: 11/30/2022]
|
20
|
Castellar A, Bertoli PC, Galdino LH, Domeniconi RF, Cruz-Neto AP. Differences in physiological traits associated with water balance among rodents, and their relationship to tolerance of habitat fragmentation. ACTA ACUST UNITED AC 2015; 323:731-744. [PMID: 26349625 DOI: 10.1002/jez.1966] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 07/27/2015] [Accepted: 08/11/2015] [Indexed: 11/06/2022]
Abstract
Physiological concepts and tools can help us to understand why organisms and populations respond to habitat fragmentation in the way they do, and allow us to determine the mechanisms or individual characteristics underlying this differential sensitivity. Here, we examine food intake, relative medullary thickness and distribution/expression of water channel aquaporin-1 in three species of South American rodents that have been reported to have different levels of tolerance to habitat fragmentation (Akodon montensis, Oligoryzomys nigripes, and Euryoryzomys russatus), using a classic water deprivation experiment to assess their abilities to cope with water shortage. We believe the mechanisms underlying this differential sensitivity are related to the organisms' capacities to maintain water balance, and therefore the species more tolerant to habitat fragmentation (A. montensis and O. nigripes) should have a higher capacity to maintain water balance. We found that A. montensis and O. nigripes were more tolerant to water deprivation than E. russatus, and this difference appears to be unrelated to differences in food ingestion rate. O. nigripes showed the highest values for RMT, followed by A. montensis and E. russatus. However all species showed RMT values that were 2.2% to 14.1% below the lower prediction limit when compared to other rodents through allometric relationships. Water deprivation seems to trigger changes in the distribution of aquaporin-1, mostly for O. nigripes and E. russatus, which may contribute to water balance maintenance. Our data suggest that these intrinsic physiological differences among these species could provide a mechanism for their differential tolerance of habitat fragmentation. J. Exp. Zool. 323A: 731-744, 2015. © 2015 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Alexandre Castellar
- Department of Zoology, Biosciences Institute, UNESP - Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | - Paula Custódio Bertoli
- Department of Zoology, Biosciences Institute, UNESP - Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| | | | - Raquel Fantin Domeniconi
- Department of Anatomy, Biosciences Institute, UNESP - Universidade Estadual Paulista, Botucatu, São Paulo, Brazil
| | - Ariovaldo Pereira Cruz-Neto
- Department of Zoology, Biosciences Institute, UNESP - Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil
| |
Collapse
|
21
|
Packard GC. Quantifying the curvilinear metabolic scaling in mammals. ACTA ACUST UNITED AC 2015; 323:540-6. [DOI: 10.1002/jez.1946] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Accepted: 05/05/2015] [Indexed: 11/06/2022]
Affiliation(s)
- Gary C. Packard
- Department of Biology; Colorado State University; Fort Collins Colorado
| |
Collapse
|
22
|
Body mass estimates of hominin fossils and the evolution of human body size. J Hum Evol 2015; 85:75-93. [PMID: 26094042 DOI: 10.1016/j.jhevol.2015.05.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 05/06/2015] [Accepted: 05/07/2015] [Indexed: 12/29/2022]
Abstract
Body size directly influences an animal's place in the natural world, including its energy requirements, home range size, relative brain size, locomotion, diet, life history, and behavior. Thus, an understanding of the biology of extinct organisms, including species in our own lineage, requires accurate estimates of body size. Since the last major review of hominin body size based on postcranial morphology over 20 years ago, new fossils have been discovered, species attributions have been clarified, and methods improved. Here, we present the most comprehensive and thoroughly vetted set of individual fossil hominin body mass predictions to date, and estimation equations based on a large (n = 220) sample of modern humans of known body masses. We also present species averages based exclusively on fossils with reliable taxonomic attributions, estimates of species averages by sex, and a metric for levels of sexual dimorphism. Finally, we identify individual traits that appear to be the most reliable for mass estimation for each fossil species, for use when only one measurement is available for a fossil. Our results show that many early hominins were generally smaller-bodied than previously thought, an outcome likely due to larger estimates in previous studies resulting from the use of large-bodied modern human reference samples. Current evidence indicates that modern human-like large size first appeared by at least 3-3.5 Ma in some Australopithecus afarensis individuals. Our results challenge an evolutionary model arguing that body size increased from Australopithecus to early Homo. Instead, we show that there is no reliable evidence that the body size of non-erectus early Homo differed from that of australopiths, and confirm that Homo erectus evolved larger average body size than earlier hominins.
Collapse
|
23
|
White CR, Kearney MR. Metabolic scaling in animals: methods, empirical results, and theoretical explanations. Compr Physiol 2014; 4:231-56. [PMID: 24692144 DOI: 10.1002/cphy.c110049] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Life on earth spans a size range of around 21 orders of magnitude across species and can span a range of more than 6 orders of magnitude within species of animal. The effect of size on physiology is, therefore, enormous and is typically expressed by how physiological phenomena scale with mass(b). When b ≠ 1 a trait does not vary in direct proportion to mass and is said to scale allometrically. The study of allometric scaling goes back to at least the time of Galileo Galilei, and published scaling relationships are now available for hundreds of traits. Here, the methods of scaling analysis are reviewed, using examples for a range of traits with an emphasis on those related to metabolism in animals. Where necessary, new relationships have been generated from published data using modern phylogenetically informed techniques. During recent decades one of the most controversial scaling relationships has been that between metabolic rate and body mass and a number of explanations have been proposed for the scaling of this trait. Examples of these mechanistic explanations for metabolic scaling are reviewed, and suggestions made for comparing between them. Finally, the conceptual links between metabolic scaling and ecological patterns are examined, emphasizing the distinction between (1) the hypothesis that size- and temperature-dependent variation among species and individuals in metabolic rate influences ecological processes at levels of organization from individuals to the biosphere and (2) mechanistic explanations for metabolic rate that may explain the size- and temperature-dependence of this trait.
Collapse
Affiliation(s)
- Craig R White
- School of Biological Sciences, The University of Queensland, St Lucia, Queensland, Australia
| | | |
Collapse
|
24
|
Packard GC. On the use of log-transformation versus nonlinear regression for analyzing biological power laws. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12396] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Gary C. Packard
- Department of Biology; Colorado State University; Fort Collins CO 80523-1878 USA
| |
Collapse
|
25
|
Trotta V, Duran Prieto J, Battaglia D, Fanti P. Plastic responses of some life history traits and cellular components of body size inAphidius ervias related to the age of its hostAcyrthosiphon pisum. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12354] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Vincenzo Trotta
- Dipartimento di Scienze; Università della Basilicata; Viale dell'Ateneo Lucano 10 85100 Potenza Italy
| | - Juliana Duran Prieto
- Dipartimento di Scienze; Università della Basilicata; Viale dell'Ateneo Lucano 10 85100 Potenza Italy
| | - Donatella Battaglia
- Dipartimento di Scienze; Università della Basilicata; Viale dell'Ateneo Lucano 10 85100 Potenza Italy
| | - Paolo Fanti
- Dipartimento di Scienze; Università della Basilicata; Viale dell'Ateneo Lucano 10 85100 Potenza Italy
| |
Collapse
|
26
|
Mathematical model for the contribution of individual organs to non-zero y-intercepts in single and multi-compartment linear models of whole-body energy expenditure. PLoS One 2014; 9:e103301. [PMID: 25068692 PMCID: PMC4113365 DOI: 10.1371/journal.pone.0103301] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 06/26/2014] [Indexed: 12/12/2022] Open
Abstract
Mathematical models for the dependence of energy expenditure (EE) on body mass and composition are essential tools in metabolic phenotyping. EE scales over broad ranges of body mass as a non-linear allometric function. When considered within restricted ranges of body mass, however, allometric EE curves exhibit ‘local linearity.’ Indeed, modern EE analysis makes extensive use of linear models. Such models typically involve one or two body mass compartments (e.g., fat free mass and fat mass). Importantly, linear EE models typically involve a non-zero (usually positive) y-intercept term of uncertain origin, a recurring theme in discussions of EE analysis and a source of confounding in traditional ratio-based EE normalization. Emerging linear model approaches quantify whole-body resting EE (REE) in terms of individual organ masses (e.g., liver, kidneys, heart, brain). Proponents of individual organ REE modeling hypothesize that multi-organ linear models may eliminate non-zero y-intercepts. This could have advantages in adjusting REE for body mass and composition. Studies reveal that individual organ REE is an allometric function of total body mass. I exploit first-order Taylor linearization of individual organ REEs to model the manner in which individual organs contribute to whole-body REE and to the non-zero y-intercept in linear REE models. The model predicts that REE analysis at the individual organ-tissue level will not eliminate intercept terms. I demonstrate that the parameters of a linear EE equation can be transformed into the parameters of the underlying ‘latent’ allometric equation. This permits estimates of the allometric scaling of EE in a diverse variety of physiological states that are not represented in the allometric EE literature but are well represented by published linear EE analyses.
Collapse
|
27
|
Pusey H, Cooper CE, Withers PC. Metabolic, hygric and ventilatory physiology of the red-tailed phascogale (Phascogale calura; Marsupialia, Dasyuridae): Adaptations to aridity or arboreality? Mamm Biol 2013. [DOI: 10.1016/j.mambio.2012.11.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
28
|
Affiliation(s)
- Gary C. Packard
- Department of Biology; Colorado State University; Fort Collins CO 80523-1878 USA
| |
Collapse
|
29
|
Withers PC, Cooper CE, Nespolo RF. Evaporative water loss, relative water economy and evaporative partitioning of a heterothermic marsupial, the monito del monte (Dromiciops gliroides). ACTA ACUST UNITED AC 2012; 215:2806-13. [PMID: 22837452 DOI: 10.1242/jeb.070433] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We examine here evaporative water loss, economy and partitioning at ambient temperatures from 14 to 33°C for the monito del monte (Dromiciops gliroides), a microbiotheriid marsupial found only in temperate rainforests of Chile. The monito's standard evaporative water loss (2.58 mg g(-1) h(-1) at 30°C) was typical for a marsupial of its body mass and phylogenetic position. Evaporative water loss was independent of air temperature below thermoneutrality, but enhanced evaporative water loss and hyperthermia were the primary thermal responses above the thermoneutral zone. Non-invasive partitioning of total evaporative water loss indicated that respiratory loss accounted for 59-77% of the total, with no change in respiratory loss with ambient temperature, but a small change in cutaneous loss below thermoneutrality and an increase in cutaneous loss in and above thermoneutrality. Relative water economy (metabolic water production/evaporative water loss) increased at low ambient temperatures, with a point of relative water economy of 15.4°C. Thermolability had little effect on relative water economy, but conferred substantial energy savings at low ambient temperatures. Torpor reduced total evaporative water loss to as little as 21% of normothermic values, but relative water economy during torpor was poor even at low ambient temperatures because of the relatively greater reduction in metabolic water production than in evaporative water loss. The poor water economy of the monito during torpor suggests that negative water balance may explain why hibernators periodically arouse to normothermia, to obtain water by drinking or via an improved water economy.
Collapse
Affiliation(s)
- Philip C Withers
- School of Animal Biology M092, University of Western Australia, Crawley, WA 6009, Australia.
| | | | | |
Collapse
|
30
|
Barker JM, Cooper CE, Withers PC, Cruz-Neto AP. Thermoregulation by an Australian murine rodent, the ash-grey mouse (Pseudomys albocinereus). Comp Biochem Physiol A Mol Integr Physiol 2012; 163:336-42. [DOI: 10.1016/j.cbpa.2012.07.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 07/20/2012] [Accepted: 07/20/2012] [Indexed: 12/01/2022]
|
31
|
Laliberté E, Adair EC, Hobbie SE. Estimating litter decomposition rate in single-pool models using nonlinear beta regression. PLoS One 2012; 7:e45140. [PMID: 23049771 PMCID: PMC3458010 DOI: 10.1371/journal.pone.0045140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2012] [Accepted: 08/13/2012] [Indexed: 12/02/2022] Open
Abstract
Litter decomposition rate (k) is typically estimated from proportional litter mass loss data using models that assume constant, normally distributed errors. However, such data often show non-normal errors with reduced variance near bounds (0 or 1), potentially leading to biased k estimates. We compared the performance of nonlinear regression using the beta distribution, which is well-suited to bounded data and this type of heteroscedasticity, to standard nonlinear regression (normal errors) on simulated and real litter decomposition data. Although the beta model often provided better fits to the simulated data (based on the corrected Akaike Information Criterion, AICc), standard nonlinear regression was robust to violation of homoscedasticity and gave equally or more accurate k estimates as nonlinear beta regression. Our simulation results also suggest that k estimates will be most accurate when study length captures mid to late stage decomposition (50–80% mass loss) and the number of measurements through time is ≥5. Regression method and data transformation choices had the smallest impact on k estimates during mid and late stage decomposition. Estimates of k were more variable among methods and generally less accurate during early and end stage decomposition. With real data, neither model was predominately best; in most cases the models were indistinguishable based on AICc, and gave similar k estimates. However, when decomposition rates were high, normal and beta model k estimates often diverged substantially. Therefore, we recommend a pragmatic approach where both models are compared and the best is selected for a given data set. Alternatively, both models may be used via model averaging to develop weighted parameter estimates. We provide code to perform nonlinear beta regression with freely available software.
Collapse
Affiliation(s)
- Etienne Laliberté
- School of Plant Biology, The University of Western Australia, Crawley, Western Australia, Australia
| | - E. Carol Adair
- National Center for Ecological Analysis and Synthesis, University of California Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Sarah E. Hobbie
- Department of Ecology, Evolution and Behavior, University of Minnesota, Saint Paul, Minnesota, United States of America
| |
Collapse
|
32
|
Tomlinson S, Withers PC, Maloney SK. Comparative thermoregulatory physiology of two dunnarts, Sminthopsis macroura and Sminthopsis ooldea (Marsupialia : Dasyuridae). AUST J ZOOL 2012. [DOI: 10.1071/zo12034] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Metabolic rate and evaporative water loss (EWL) were measured to quantify the thermoregulatory patterns of two dasyurids, the stripe-faced dunnart (Sminthopsis macroura) and the Ooldea dunnart (S. ooldea) during acute exposure to Ta between 10 and 35°C. S. macroura maintained consistent Tb across the Ta range, whereas S. ooldea was more thermolabile. The metabolic rate of both species decreased from Ta = 10°C to BMR at Ta = 30°C. Mass-adjusted BMR at Ta = 30°C was the same for the two species, but there was no common regression of metabolic rate below the thermoneutral zone (TNZ). There was no significant difference between the species in allometrically corrected EWL at Ta = 30°C. Total EWL increased significantly at Ta = 10 and 35°C compared with the TNZ for S. macroura, but was consistent across the Ta range for S. ooldea. At any Ta below the TNZ, S. macroura required more energy per gram of body mass than S. ooldea, and had a higher EWL at the lower critical Ta. By being thermolabile S. ooldea reduced its energetic requirements and water loss at low Ta. The more constant thermoregulatory strategy of S. macroura may allow it to exploit a broad climatic envelope, albeit at the cost of higher energetic and water requirements. Since S. ooldea does not expend as much energy and water on thermoregulation this may be a response to the very low productivity, ‘hyperarid’ conditions of its central Australian distribution.
Collapse
|
33
|
Xiao X, White EP, Hooten MB, Durham SL. On the use of log-transformation vs. nonlinear regression for analyzing biological power laws. Ecology 2011; 92:1887-94. [PMID: 22073779 DOI: 10.1890/11-0538.1] [Citation(s) in RCA: 220] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Power-law relationships are among the most well-studied functional relationships in biology. Recently the common practice of fitting power laws using linear regression (LR) on log-transformed data has been criticized, calling into question the conclusions of hundreds of studies. It has been suggested that nonlinear regression (NLR) is preferable, but no rigorous comparison of these two methods has been conducted. Using Monte Carlo simulations, we demonstrate that the error distribution determines which method performs better, with NLR better characterizing data with additive, homoscedastic, normal error and LR better characterizing data with multiplicative, heteroscedastic, lognormal error. Analysis of 471 biological power laws shows that both forms of error occur in nature. While previous analyses based on log-transformation appear to be generally valid, future analyses should choose methods based on a combination of biological plausibility and analysis of the error distribution. We provide detailed guidelines and associated computer code for doing so, including a model averaging approach for cases where the error structure is uncertain.
Collapse
Affiliation(s)
- Xiao Xiao
- Department of Biology, Utah State University, Logan, Utah 84322-5305, USA.
| | | | | | | |
Collapse
|
34
|
White CR, Kearney MR, Matthews PGD, Kooijman SALM, Marshall DJ. A Manipulative Test of Competing Theories for Metabolic Scaling. Am Nat 2011; 178:746-54. [DOI: 10.1086/662666] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
35
|
Munn AJ, Cooper CE, Russell B, Dawson TJ, McLeod SR, Maloney SK. Energy and water use by invasive goats (Capra hircus) in an Australian rangeland, and a caution against using broad-scale allometry to predict species-specific requirements. Comp Biochem Physiol A Mol Integr Physiol 2011; 161:216-29. [PMID: 22079103 DOI: 10.1016/j.cbpa.2011.10.027] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Revised: 10/28/2011] [Accepted: 10/29/2011] [Indexed: 10/15/2022]
Abstract
Feral goats (Capra hircus) are ubiquitous across much of Australia's arid and semi-arid rangelands, where they compete with domestic stock, contribute to grazing pressure on fragile ecosystems, and have been implicated in the decline of several native marsupial herbivores. Understanding the success of feral goats in Australia may provide insights into management strategies for this and other invasive herbivores. It has been suggested that frugal use of energy and water contributes to the success of feral goats in Australia, but data on the energy and water use of free-ranging animals are lacking. We measured the field metabolic rate and water turnover rate of pregnant and non-pregnant feral goats in an Australian rangeland during late summer (dry season). Field metabolic rate of pregnant goats (601 ± 37 kJ kg(-0.73)d(-1)) was 1.3 times that of non-pregnant goats (456 ± 24 kJ kg(-0.73)d(-1)). The water turnover rate of pregnant goats (228 ± 18 mL kg(-0.79)d(-1)) was also 1.3 times that of non-pregnant goats (173 ± 18 kg(-0.79)d(-1)), but the difference was not significant (P=0.07). There was no significant difference in estimated dry matter digestibility between pregnant and non-pregnant goats (mean ca. 58%), blood or urine osmolality, or urine electrolyte concentrations, indicating they were probably eating similar diets and were able to maintain osmohomeostasis. Overall, the metabolic and hygric physiology of non-pregnant goats conformed statistically to the predictions for non-marine, non-reproductive placental mammals according to both conventional and phylogenetically independent analyses. That was despite the field metabolic rate and estimated dry matter intake of non-pregnant goats being only 60% of the predicted level. We suggest that general allometric analyses predict the range of adaptive possibilities for mammals, but that specific adaptations, as present in goats, result in ecologically significant departures from the average allometric curve. In the case of goats in the arid Australian rangelands, predictions from the allometric regression would overestimate their grazing pressure by about 40% with implications for the predicted impact on their local ecology.
Collapse
Affiliation(s)
- A J Munn
- Institute of Conservation Biology and Environmental Management, School of Biological Sciences, University of Wollongong, Australia.
| | | | | | | | | | | |
Collapse
|
36
|
Phylogenetic rate shifts in feeding time during the evolution of Homo. Proc Natl Acad Sci U S A 2011; 108:14555-9. [PMID: 21873223 DOI: 10.1073/pnas.1107806108] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Unique among animals, humans eat a diet rich in cooked and nonthermally processed food. The ancestors of modern humans who invented food processing (including cooking) gained critical advantages in survival and fitness through increased caloric intake. However, the time and manner in which food processing became biologically significant are uncertain. Here, we assess the inferred evolutionary consequences of food processing in the human lineage by applying a Bayesian phylogenetic outlier test to a comparative dataset of feeding time in humans and nonhuman primates. We find that modern humans spend an order of magnitude less time feeding than predicted by phylogeny and body mass (4.7% vs. predicted 48% of daily activity). This result suggests that a substantial evolutionary rate change in feeding time occurred along the human branch after the human-chimpanzee split. Along this same branch, Homo erectus shows a marked reduction in molar size that is followed by a gradual, although erratic, decline in H. sapiens. We show that reduction in molar size in early Homo (H. habilis and H. rudolfensis) is explicable by phylogeny and body size alone. By contrast, the change in molar size to H. erectus, H. neanderthalensis, and H. sapiens cannot be explained by the rate of craniodental and body size evolution. Together, our results indicate that the behaviorally driven adaptations of food processing (reduced feeding time and molar size) originated after the evolution of Homo but before or concurrent with the evolution of H. erectus, which was around 1.9 Mya.
Collapse
|
37
|
Packard GC. Rotational distortion in conventional allometric analyses. Comp Biochem Physiol A Mol Integr Physiol 2011; 159:392-400. [DOI: 10.1016/j.cbpa.2011.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 04/12/2011] [Accepted: 04/12/2011] [Indexed: 11/28/2022]
|
38
|
Unanticipated consequences of logarithmic transformation in bivariate allometry. J Comp Physiol B 2011; 181:841-9. [DOI: 10.1007/s00360-011-0565-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2011] [Revised: 02/14/2011] [Accepted: 02/23/2011] [Indexed: 10/18/2022]
|
39
|
White CR. Allometric estimation of metabolic rates in animals. Comp Biochem Physiol A Mol Integr Physiol 2011; 158:346-57. [DOI: 10.1016/j.cbpa.2010.10.004] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Revised: 10/01/2010] [Accepted: 10/01/2010] [Indexed: 10/19/2022]
|
40
|
Packard GC, Birchard GF, Boardman TJ. Fitting statistical models in bivariate allometry. Biol Rev Camb Philos Soc 2010; 86:549-63. [DOI: 10.1111/j.1469-185x.2010.00160.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
41
|
Terblanche JS, Clusella-Trullas S, Chown SL. Phenotypic plasticity of gas exchange pattern and water loss in Scarabaeus spretus (Coleoptera: Scarabaeidae): deconstructing the basis for metabolic rate variation. J Exp Biol 2010; 213:2940-9. [DOI: 10.1242/jeb.041889] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARY
Investigation of gas exchange patterns and modulation of metabolism provide insight into metabolic control systems and evolution in diverse terrestrial environments. Variation in metabolic rate in response to environmental conditions has been explained largely in the context of two contrasting hypotheses, namely metabolic depression in response to stressful or resource-(e.g. water) limited conditions, or elevation of metabolism at low temperatures to sustain life in extreme conditions. To deconstruct the basis for metabolic rate changes in response to temperature variation, here we undertake a full factorial study investigating the longer- and short-term effects of temperature exposure on gas exchange patterns. We examined responses of traits of gas exchange [standard metabolic rate (SMR); discontinuous gas exchange (DGE) cycle frequency; cuticular, respiratory and total water loss rate (WLR)] to elucidate the magnitude and form of plastic responses in the dung beetle, Scarabaeus spretus. Results showed that short- and longer-term temperature variation generally have significant effects on SMR and WLR. Overall, acclimation to increased temperature led to a decline in SMR (from 0.071±0.004 ml CO2 h–1 in 15°C-acclimated beetles to 0.039±0.004 ml CO2 h–1 in 25°C-acclimated beetles measured at 20°C) modulated by reduced DGE frequency (15°C acclimation: 0.554±0.027 mHz, 20°C acclimation: 0.257±0.030 mHz, 25°C acclimation: 0.208±0.027 mHz recorded at 20°C), reduced cuticular WLRs (from 1.058±0.537 mg h–1 in 15°C-acclimated beetles to 0.900±0.400 mg h–1 in 25°C-acclimated beetles measured at 20°C) and reduced total WLR (from 4.2±0.5 mg h–1 in 15°C-acclimated beetles to 3.1±0.5 mg h–1 in 25°C-acclimated beetles measured at 25°C). Respiratory WLR was reduced from 2.25±0.40 mg h–1 in 15°C-acclimated beetles to 1.60±0.40 mg h–1 in 25°C-acclimated beetles measured at 25°C, suggesting conservation of water during DGE bursts. Overall, this suggests water conservation is a priority for S. spretus exposed to longer-term temperature variation, rather than elevation of SMR in response to low temperature acclimation, as might be expected from a beetle living in a relatively warm, low rainfall summer region. These results are significant for understanding the evolution of gas exchange patterns and trade-offs between metabolic rate and water balance in insects and other terrestrial arthropods.
Collapse
Affiliation(s)
- John S. Terblanche
- Department of Conservation Ecology and Entomology, Faculty of AgriSciences, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Susana Clusella-Trullas
- Centre for Invasion Biology, Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Steven L. Chown
- Centre for Invasion Biology, Department of Botany and Zoology, Faculty of Science, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| |
Collapse
|
42
|
Warnecke L, Cooper C, Geiser F, Withers P. Environmental physiology of a small marsupial inhabiting arid floodplains. Comp Biochem Physiol A Mol Integr Physiol 2010; 157:73-8. [DOI: 10.1016/j.cbpa.2010.04.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2010] [Revised: 04/29/2010] [Accepted: 04/29/2010] [Indexed: 10/19/2022]
|
43
|
Cooper CE, Withers PC. Comparative physiology of Australian quolls (Dasyurus; Marsupialia). J Comp Physiol B 2010; 180:857-68. [PMID: 20217094 DOI: 10.1007/s00360-010-0452-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Revised: 02/01/2010] [Accepted: 02/03/2010] [Indexed: 11/30/2022]
Abstract
Quolls (Dasyurus) are medium-sized carnivorous dasyurid marsupials. Tiger (3,840 g) and eastern quolls (780 g) are mesic zone species, northern quolls (516 g) are tropical zone, and chuditch (1,385 g) were once widespread through the Australian arid zone. We found that standard physiological variables of these quolls are consistent with allometric expectations for marsupials. Nevertheless, inter-specific patterns amongst the quolls are consistent with their different environments. The lower T (b) of northern quolls (34 degrees C) may provide scope for adaptive hyperthermia in the tropics, and they use torpor for energy/water conservation, whereas the larger mesic species (eastern and tiger quolls) do not appear to. Thermolability varied from little in eastern (0.035 degrees C degrees C(-1)) and tiger quolls (0.051 degrees C degrees C(-1)) to substantial in northern quolls (0.100 degrees C degrees C(-1)) and chuditch (0.146 degrees C degrees C(-1)), reflecting body mass and environment. Basal metabolic rate was higher for eastern quolls (0.662 +/- 0.033 ml O(2) g(-1) h(-1)), presumably reflecting their naturally cool environment. Respiratory ventilation closely matched metabolic demand, except at high ambient temperatures where quolls hyperventilated to facilitate evaporative heat loss; tiger and eastern quolls also salivated. A higher evaporative water loss for eastern quolls (1.43 +/- 0.212 mg H(2)O g(-1) h(-1)) presumably reflects their more mesic distribution. The point of relative water economy was low for tiger (-1.3 degrees C), eastern (-12.5 degrees C) and northern (+3.3) quolls, and highest for the chuditch (+22.6 degrees C). We suggest that these differences in water economy reflect lower expired air temperatures and hence lower respiratory evaporative water loss for the arid-zone chuditch relative to tropical and mesic quolls.
Collapse
Affiliation(s)
- Christine E Cooper
- Department of Environmental and Aquatic Sciences, Curtin University of Technology, PO Box U1987, Bentley, Perth, WA, 6845, Australia.
| | | |
Collapse
|
44
|
Cooper CE, Withers PC, Cruz-Neto AP. Metabolic, ventilatory, and hygric physiology of a South American marsupial, the long-furred woolly mouse opossum. J Mammal 2010. [DOI: 10.1644/09-mamm-a-138r.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
45
|
Chown SL, Gaston KJ. Body size variation in insects: a macroecological perspective. Biol Rev Camb Philos Soc 2010; 85:139-69. [DOI: 10.1111/j.1469-185x.2009.00097.x] [Citation(s) in RCA: 455] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
46
|
Hui C, Terblanche JS, Chown SL, McGeoch MA. Parameter landscapes unveil the bias in allometric prediction. Methods Ecol Evol 2010. [DOI: 10.1111/j.2041-210x.2009.00005.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
47
|
Peig J, Green AJ. New perspectives for estimating body condition from mass/length data: the scaled mass index as an alternative method. OIKOS 2009. [DOI: 10.1111/j.1600-0706.2009.17643.x] [Citation(s) in RCA: 1089] [Impact Index Per Article: 72.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
48
|
Schmidt S, Withers P, Cooper C. Metabolic, ventilatory and hygric physiology of the chuditch (Dasyurus geoffroii; Marsupialia, Dasyuridae). Comp Biochem Physiol A Mol Integr Physiol 2009; 154:92-7. [DOI: 10.1016/j.cbpa.2009.05.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/07/2009] [Accepted: 05/08/2009] [Indexed: 11/28/2022]
|
49
|
|
50
|
Withers PC, Cooper CE. Thermal, Metabolic, and Hygric Physiology of the Little Red Kaluta,Dasykaluta rosamondae(Dasyuromorphia: Dasyuridae). J Mammal 2009. [DOI: 10.1644/08-mamm-a-286r.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|