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Shorten PR, Morris CA, Cullen NG. The effects of age, weight, and sire on pregnancy rate in cattle. J Anim Sci 2016; 93:1535-45. [PMID: 26020175 DOI: 10.2527/jas.2014-8490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The goal was to estimate the heritabilities and genetic variances for pregnancy rate (PR) and calving date (CD) in Angus cattle along with the effect of weight, age, and sire on PR and CD. The data consisted of 4,999 records on PR and CD. Statistical models included year as a fixed effect; premating/postmating weight and age as covariates; and sire of embryo, maternal grandsire (MGS), and permanent maternal environmental effects as random effects. The models also included the interactions between herd and weight (weight change). Direct and maternal effects on PR and CD were estimated using sire MGS and animal models in REML. Pregnancy rate increased from age 2 to 6 and decreased from age 7 to 11 (P < 0.01) and this effect was independent of the culling strategy. There was a quadratic effect of premating cow weight independent of age on PR, with lower PR for low weights (P < 0.01). Overall, cows with a premating weight of 550 kg had the greatest PR. Cows that lost weight during mating had lower PR (P < 0.01). The maternal additive heritability for PR was 0.001 ± 0.012 and the direct additive heritability was 0.024 ± 0.020. The ratio of permanent maternal environmental variance to phenotypic variance was significant (0.048 ± 0.017; P < 0.01). This demonstrates that permanent maternal environmental effects play a major role in the repeatability of PR (0.049 ± 0.015; P < 0.01). The maternal additive heritability for CD was 0.040 ± 0.022, and the direct additive heritability was 0.076 ± 0.045. The ratio of permanent maternal environmental variance to phenotypic variance was low (0.014 ± 0.017) and the repeatability for CD was significant (0.0544 ± 0.0180; P < 0.01). This suggests that maternal genetic effects are as important as direct genetic effects on CD. There was a positive quadratic relationship between premating cow weight and CD with delayed calving for low/high weights (P < 0.01). Cows that lost weight over mating also had a later CD (P < 0.01). Comparisons of a weight-selected herd to the control herd showed differences (P < 0.05) in the optimal premating weight for early calving (control, 480 kg, and weight selected, 615 kg). Calving date was also more sensitive to changes in weight over mating in the weight selection herd (P < 0.05). Therefore, the set point in the weight-fertility axis and the sensitivity of fertility to changes in weight both changed in the weight selection herd.
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52
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Ellsworth E, Boudreau M, Nagy K, Rachlow J, Murray D. Differential sex-related winter energetics in free-ranging snowshoe hares ( Lepus americanus). CAN J ZOOL 2016. [DOI: 10.1139/cjz-2015-0074] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Animals spend considerable time and energy acquiring food to meet their metabolic requirements, but if energetic or fitness costs are substantive, such as during winter, then some individuals may limit daily energy expenditure by reducing foraging duration. To date, the prevalence and magnitude of such compensatory foraging responses are poorly known. We examined energy balance compensation in free-ranging snowshoe hares (Lepus americanus Erxleben, 1777) via a food supplementation experiment to determine whether individuals reduced their daily energy expenditure (DEE) and activity periods in response to increased food availability. Overall, food supplementation had no effect on diel activity patterns, although males had higher DEE compared with females. During early and mid-winter, hares did not alter their activity periods in response to food supplementation, but during late winter, when natural food availability declined, food-supplemented females (but not males) were ∼11% less active compared with controls. Natural food likely was sufficient and could have been acquired at relatively low energetic cost, but because males likely have higher DEE due to mating behavior whereas females may limit their activity (and thus DEE) to reduce predation risk, we conclude that gender-specific life-history demands can over-ride predicted responses to supplemental food when baseline food abundance is adequate.
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Affiliation(s)
- E. Ellsworth
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - M.R. Boudreau
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
| | - K. Nagy
- Department of Ecology and Evolutionary Biology, University of California, 621 Young Drive South, Los Angeles, CA 90095-1606, USA
| | - J.L. Rachlow
- Department of Fish and Wildlife Sciences, University of Idaho, 875 Perimeter Drive, MS 1136, Moscow, ID 83843-1136, USA
| | - D.L. Murray
- Department of Biology, Trent University, Peterborough, ON K97 7B8, Canada
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Jacobs DS, Mutumi GL, Maluleke T, Webala PW. Convergence as an Evolutionary Trade-off in the Evolution of Acoustic Signals: Echolocation in Horseshoe Bats as a Case Study. Evol Biol 2016. [DOI: 10.1007/978-3-319-41324-2_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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54
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Abd Mutalib AH, Fadzly N, Ahmad A, Nasir N. Understanding nesting ecology and behaviour of green marine turtles at Setiu, Terengganu, Malaysia. MARINE ECOLOGY 2015; 36:1003-1012. [DOI: 10.1111/maec.12197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Affiliation(s)
| | - Nik Fadzly
- School of Biological Sciences; Universiti Sains Malaysia; Penang Malaysia
- Centre For Marine & Coastal Studies (CEMACS); Universiti Sains Malaysia; Penang Malaysia
| | - Amirrudin Ahmad
- Department of Biological Sciences; Faculty of Science and Technology; Universiti Malaysia Terengganu; Terengganu Malaysia
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55
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Grosman AH, Molina-Rugama AJ, Mendes-Dias R, Sabelis MW, Menken SBJ, Pallini A, Breeuwer JAJ, Janssen A. No adaptation of a herbivore to a novel host but loss of adaptation to its native host. Sci Rep 2015; 5:16211. [PMID: 26577696 PMCID: PMC4649677 DOI: 10.1038/srep16211] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/05/2015] [Indexed: 11/25/2022] Open
Abstract
Most herbivorous arthropods are host specialists and the question is which mechanisms drive the evolution of such specialization. The theory of antagonistic pleiotropy suggests that there is a trade-off between adaptation of herbivores to a novel host and their native host. The mutation accumulation hypothesis proposes that herbivores on a novel host lose their adaptation to the native host through the accumulation of mutations with negligible effects on performance on the novel host. Experimental evidence for either of the two hypotheses is scarce. We compared the fitness of two sympatric moth strains from an introduced host and a native host. The strain from the novel host did not perform better on this host than the strain from the native host. The strain from the novel host performed less well on the native host than did the strain from the native host. Hence, selection on the novel host did not result in noticeable gain in performance, but adaptation to the native host was lost. These results are more readily explained by the mutation-accumulation hypothesis than by the trade-off hypothesis.
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Affiliation(s)
- Amir H Grosman
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | | | | | - Maurice W Sabelis
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Steph B J Menken
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Angelo Pallini
- Department of Entomology, Federal University of Viçosa, Minas Gerais, Brazil
| | - Johannes A J Breeuwer
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Arne Janssen
- Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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56
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Foster SA, Wund MA, Graham MA, Earley RL, Gardiner R, Kearns T, Baker JA. Iterative development and the scope for plasticity: contrasts among trait categories in an adaptive radiation. Heredity (Edinb) 2015; 115:335-48. [PMID: 26243135 PMCID: PMC4815453 DOI: 10.1038/hdy.2015.66] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 06/02/2015] [Accepted: 06/04/2015] [Indexed: 01/19/2023] Open
Abstract
Phenotypic plasticity can influence evolutionary change in a lineage, ranging from facilitation of population persistence in a novel environment to directing the patterns of evolutionary change. As the specific nature of plasticity can impact evolutionary consequences, it is essential to consider how plasticity is manifested if we are to understand the contribution of plasticity to phenotypic evolution. Most morphological traits are developmentally plastic, irreversible, and generally considered to be costly, at least when the resultant phenotype is mis-matched to the environment. At the other extreme, behavioral phenotypes are typically activational (modifiable on very short time scales), and not immediately costly as they are produced by constitutive neural networks. Although patterns of morphological and behavioral plasticity are often compared, patterns of plasticity of life history phenotypes are rarely considered. Here we review patterns of plasticity in these trait categories within and among populations, comprising the adaptive radiation of the threespine stickleback fish Gasterosteus aculeatus. We immediately found it necessary to consider the possibility of iterated development, the concept that behavioral and life history trajectories can be repeatedly reset on activational (usually behavior) or developmental (usually life history) time frames, offering fine tuning of the response to environmental context. Morphology in stickleback is primarily reset only in that developmental trajectories can be altered as environments change over the course of development. As anticipated, the boundaries between the trait categories are not clear and are likely to be linked by shared, underlying physiological and genetic systems.
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Affiliation(s)
- S A Foster
- Department of Biology, Clark University, Worcester, MA, USA
| | - M A Wund
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | - M A Graham
- Department of Biology, Clark University, Worcester, MA, USA
| | - R L Earley
- Department of Biological Sciences, University of Alabama, Tuscaloosa, AL, USA
| | - R Gardiner
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | - T Kearns
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | - J A Baker
- Department of Biology, Clark University, Worcester, MA, USA
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57
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Baker JA, Wund MA, Heins DC, King RW, Reyes ML, Foster SA. Life-history plasticity in female threespine stickleback. Heredity (Edinb) 2015; 115:322-34. [PMID: 26286665 DOI: 10.1038/hdy.2015.65] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 04/20/2015] [Accepted: 04/22/2015] [Indexed: 01/07/2023] Open
Abstract
The postglacial adaptive radiation of the threespine stickleback fish (Gasterosteus aculeatus) has been widely used to investigate the roles of both adaptive evolution and plasticity in behavioral and morphological divergence from the ancestral condition represented by present-day oceanic stickleback. These phenotypes tend to exhibit high levels of ecotypic differentiation. Population divergence in life history has also been well studied, but in contrast to behavior and morphology, the extent and importance of plasticity has been much less well studied. In this review, we summarize what is known about life-history plasticity in female threespine stickleback, considering four traits intimately associated with reproductive output: age/size at maturation, level of reproductive effort, egg size and clutch size. We envision life-history plasticity in an iterative, ontogenetic framework, in which females may express plasticity repeatedly across each of several time frames. We contrast the results of laboratory and field studies because, for most traits, these approaches give somewhat different answers. We provide ideas on what the cues might be for observed plasticity in each trait and, when possible, we inquire about the relative costs and benefits to expressed plasticity. We end with an example of how we think plasticity may play out in stickleback life history given what we know of plasticity in the ancestor.
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Affiliation(s)
- J A Baker
- Department of Biology, Clark University, Worcester, MA, USA
| | - M A Wund
- Department of Biology, The College of New Jersey, Ewing, NJ, USA
| | - D C Heins
- Department of Ecology and Evolutionary Biology, Tulane University, New Orleans, LA, USA
| | - R W King
- Department of Biology, Clark University, Worcester, MA, USA
| | - M L Reyes
- Department of Biology, Clark University, Worcester, MA, USA
| | - S A Foster
- Department of Biology, Clark University, Worcester, MA, USA
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58
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Santos-del-Blanco L, Alía R, González-Martínez SC, Sampedro L, Lario F, Climent J. Correlated genetic effects on reproduction define a domestication syndrome in a forest tree. Evol Appl 2015; 8:403-10. [PMID: 25926884 PMCID: PMC4408150 DOI: 10.1111/eva.12252] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2014] [Accepted: 02/04/2015] [Indexed: 02/03/2023] Open
Abstract
Compared to natural selection, domestication implies a dramatic change in traits linked to fitness. A number of traits conferring fitness in the wild might be detrimental under domestication, and domesticated species typically differ from their ancestors in a set of traits known as the domestication syndrome. Specifically, trade-offs between growth and reproduction are well established across the tree of life. According to allocation theory, selection for growth rate is expected to indirectly alter life-history reproductive traits, diverting resources from reproduction to growth. Here we tested this hypothesis by examining the genetic change and correlated responses of reproductive traits as a result of selection for timber yield in the tree Pinus pinaster. Phenotypic selection was carried out in a natural population, and progenies from selected trees were compared with those of control trees in a common garden experiment. According to expectations, we detected a genetic change in important life-history traits due to selection. Specifically, threshold sizes for reproduction were much higher and reproductive investment relative to size significantly lower in the selected progenies just after a single artificial selection event. Our study helps to define the domestication syndrome in exploited forest trees and shows that changes affecting developmental pathways are relevant in domestication processes of long-lived plants.
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Affiliation(s)
- Luis Santos-del-Blanco
- Department of Forest Ecology and Genetics, INIA-CIFORMadrid, Spain
- Sustainable Forest Management Research InstitutePalencia, Spain
- Department of Ecology and Evolution, University of LausanneLausanne, Switzerland
| | - Ricardo Alía
- Department of Forest Ecology and Genetics, INIA-CIFORMadrid, Spain
- Sustainable Forest Management Research InstitutePalencia, Spain
| | - Santiago C González-Martínez
- Department of Forest Ecology and Genetics, INIA-CIFORMadrid, Spain
- Sustainable Forest Management Research InstitutePalencia, Spain
| | | | - Francisco Lario
- Vivero de Maceda, Dirección Técnica, TRAGSAMaceda, Ourense, Spain
| | - José Climent
- Department of Forest Ecology and Genetics, INIA-CIFORMadrid, Spain
- Sustainable Forest Management Research InstitutePalencia, Spain
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59
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Harney E, Plaistow SJ, Paterson S. Transcriptional changes during Daphnia pulex development indicate that the maturation decision resembles a rate more than a threshold. J Evol Biol 2015; 28:944-58. [PMID: 25786891 DOI: 10.1111/jeb.12624] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 03/04/2015] [Accepted: 03/12/2015] [Indexed: 01/05/2023]
Abstract
Maturation is a critical developmental process, and the age and size at which it occurs have important fitness consequences. Although maturation is remarkably variable, certain mechanisms, including a minimum size or state threshold, are proposed to underlie the process across a broad diversity of taxa. Recent evidence suggests that thresholds may themselves be developmentally plastic, and in the crustacean Daphnia pulex it is unclear whether maturation follows a threshold or is a gradual process more akin to a rate. Changes in gene expression across four instars before and during maturation were compared in a cDNA microarray experiment. Developmental stage was treated statistically both as a discontinuous and as a continuous variable, to determine whether genes showed gradual or discrete changes in expression. The continuous analysis identified a greater number of genes with significant differential expression (45) than the discontinuous analysis (11). The majority of genes, including those coding for histones, factors relating to transcription and cell cycle processes, and a putative developmental hormone showed continuous increases or decreases in expression from the first to the fourth instars that were studied, suggestive of a prolonged and gradual maturation process. Three genes coding for a fused vitellogenin/superoxide dismutase showed increases in expression following the second instar and coincided with the posited maturation threshold, but even their expression increased in a continuous fashion.
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Affiliation(s)
- E Harney
- Institute of Integrative Biology, University of Liverpool, Liverpool, UK
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60
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Differential regulation of antagonistic pleiotropy in synthetic and natural populations suggests its role in adaptation. G3-GENES GENOMES GENETICS 2015; 5:699-709. [PMID: 25711830 PMCID: PMC4426359 DOI: 10.1534/g3.115.017020] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Antagonistic pleiotropy (AP), the ability of a gene to show opposing effects in different phenotypes, has been identified in various life history traits and complex disorders, indicating its fundamental role in balancing fitness over the course of evolution. It is intuitive that natural selection might maintain AP to allow organisms phenotypic flexibility in different environments. However, despite several attempts, little evidence exists for its role in adaptation. We performed a meta-analysis in yeast to identify the genetic basis of AP in bi-parental segregants, natural isolates, and a laboratory strain genome-wide deletion collection, by comparing growth in favorable and stress conditions. We found that whereas AP was abundant in the synthetic populations, it was absent in the natural isolates. This finding indicated resolution of trade-offs, i.e., mitigation of trade-offs over evolutionary history, probably through accumulation of compensatory mutations. In the deletion collection, organizational genes showed AP, suggesting ancient resolutions of trade-offs in the basic cellular pathways. We find abundant AP in the segregants, greater than estimated in the deletion collection or observed in previous studies, with IRA2, a negative regulator of the Ras/PKA signaling pathway, showing trade-offs across diverse environments. Additionally, IRA2 and several other Ras/PKA pathway genes showed balancing selection in isolates of S. cerevisiae and S. paradoxus, indicating that multiple alleles maintain AP in this pathway in natural populations. We propose that during AP resolution, retaining the ability to vary signaling pathways such as Ras/PKA, may provide organisms with phenotypic flexibility. However, with increasing organismal complexity AP resolution may become difficult. A partial resolution of AP could manifest as complex human diseases, and the inability to resolve AP may play a role in speciation. Our findings suggest that testing a universal phenomenon like AP across multiple experimental systems may elucidate mechanisms underlying its regulation and evolution.
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61
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Padró J, Carreira V, Corio C, Hasson E, Soto IM. Host alkaloids differentially affect developmental stability and wing vein canalization in cactophilic Drosophila buzzatii. J Evol Biol 2014; 27:2781-97. [PMID: 25366093 DOI: 10.1111/jeb.12537] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Revised: 10/16/2014] [Accepted: 10/27/2014] [Indexed: 11/27/2022]
Abstract
Host shifts cause drastic consequences on fitness in cactophilic species of Drosophila. It has been argued that changes in the nutritional values accompanying host shifts may elicit these fitness responses, but they may also reflect the presence of potentially toxic secondary compounds that affect resource quality. Recent studies reported that alkaloids extracted from the columnar cactus Trichocereus terscheckii are toxic for the developing larvae of Drosophila buzzatii. In this study, we tested the effect of artificial diets including increasing doses of host alkaloids on developmental stability and wing morphology in D. buzzatii. We found that alkaloids disrupt normal wing venation patterning and affect viability, wing size and fluctuating asymmetry, suggesting the involvement of stress-response mechanisms. Theoretical implications are discussed in the context of developmental stability, stress, fitness and their relationship with robustness, canalization and phenotypic plasticity.
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Affiliation(s)
- J Padró
- Departamento de Ecología, Genética y Evolución, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Buenos Aires, Argentina; Instituto de Ecología, Genética y Evolución de Buenos Aires (IEGEBA - CONICET/UBA), Buenos Aires, Argentina
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62
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Bjorndal KA, Parsons J, Mustin W, Bolten AB. Variation in age and size at sexual maturity in Kemp’s ridley sea turtles. ENDANGER SPECIES RES 2014. [DOI: 10.3354/esr00608] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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63
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Johannessen A, Skaret G, Langård L, Slotte A, Husebø Å, Fernö A. The dynamics of a metapopulation: changes in life-history traits in resident herring that co-occur with oceanic herring during spawning. PLoS One 2014; 9:e102462. [PMID: 25051066 PMCID: PMC4106829 DOI: 10.1371/journal.pone.0102462] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2013] [Accepted: 06/19/2014] [Indexed: 11/24/2022] Open
Abstract
Different populations of Atlantic herring are regarded as forming a metapopulation, but we know little about the dynamics of the connectivity and degree of interbreeding between the populations. Based on data from three periods between 1962 and 2011, we identified the presence of two components of herring in a small semi-enclosed coastal marine ecosystem based on different somatic growth patterns and mean vertebrae sum (VS). The two components were interpreted as belonging to a resident herring population and the migratory, oceanic Norwegian spring spawning (NSS) herring population, and they co-occurred during spawning. In the 1960s, resident herring characterized by slow growth and low VS co-occurred with rapid growth, high VS oceanic NSS herring. Similar slow-growing resident and rapid-growing NSS herring were found in the 1970–80s, but both populations now had low VS suggesting similar origins. Finally, in the 2000s both populations showed rapid growth. The changes coincided with the NSS herring going from a state of high abundance and oceanic distribution to a collapse in the late 1960s that resulted in a coastal distribution closer to resident herring populations, before full recovery and resumption of the migratory, oceanic pattern in the 1990s. During all three periods, NSS herring were only present in the local system up to an age of about five years, but the synchronous spawning of the populations supports mixed spawning and interbreeding. During the investigation period both longevity, length at age (growth) and length-at-first maturity increased markedly for the resident herring, which then became more similar to the NSS herring. Genetic and/or cultural factors are believed to be the main causes of the observed changes in life history traits, although some effect of changes in environmental factors cannot be excluded. Our study suggests that relationships among populations in a metapopulation can be highly dynamic.
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Affiliation(s)
- Arne Johannessen
- Department of Biology, University of Bergen, Bergen, Norway
- * E-mail:
| | | | - Lise Langård
- Department of Biology, University of Bergen, Bergen, Norway
- Institute of Marine Research, Bergen, Norway
| | - Aril Slotte
- Institute of Marine Research, Bergen, Norway
| | - Åse Husebø
- Institute of Marine Research, Bergen, Norway
| | - Anders Fernö
- Department of Biology, University of Bergen, Bergen, Norway
- Institute of Marine Research, Bergen, Norway
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64
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Morehouse NI. Condition-Dependent Ornaments, Life Histories, and the Evolving Architecture of Resource-Use. Integr Comp Biol 2014; 54:591-600. [DOI: 10.1093/icb/icu103] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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65
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Ab Ghani NI, Merilä J. Cross-generational costs of compensatory growth in nine-spined sticklebacks. OIKOS 2014. [DOI: 10.1111/oik.01597] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Nurul Izza Ab Ghani
- Dept of Biosciences; PO Box 65, FI-00014 University of Helsinki Finland
- Dept of Biology, Faculty of Science; Univ. of Putra Malaysia; 43400 UPM Serdang, Selangor Darul Ehsan Malaysia
| | - Juha Merilä
- Dept of Biosciences; PO Box 65, FI-00014 University of Helsinki Finland
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66
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Kleessen S, Laitinen R, Fusari CM, Antonio C, Sulpice R, Fernie AR, Stitt M, Nikoloski Z. Metabolic efficiency underpins performance trade-offs in growth of Arabidopsis thaliana. Nat Commun 2014; 5:3537. [PMID: 24675291 DOI: 10.1038/ncomms4537] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 03/04/2014] [Indexed: 12/11/2022] Open
Abstract
Growth often involves a trade-off between the performance of contending tasks; metabolic plasticity can play an important role. Here we grow 97 Arabidopsis thaliana accessions in three conditions with a differing supply of carbon and nitrogen and identify a trade-off between two tasks required for rosette growth: increasing the physical size and increasing the protein concentration. We employ the Pareto performance frontier concept to rank accessions based on their multitask performance; only a few accessions achieve a good trade-off under all three growth conditions. We determine metabolic efficiency in each accession and condition by using metabolite levels and activities of enzymes involved in growth and protein synthesis. We demonstrate that accessions with high metabolic efficiency lie closer to the performance frontier and show increased metabolic plasticity. We illustrate how public domain data can be used to search for additional contending tasks, which may underlie the sub-optimality in some accessions.
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Affiliation(s)
- Sabrina Kleessen
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Roosa Laitinen
- Molecular Mechanisms of Adaptation Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Corina M Fusari
- 1] System Regulation Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany [2] Instituto de Biotecnología, Centro Investigación en Ciencias Veterinarias y Agronómicas (CICVyA), Instituto Nacional de Tecnología Agropecuaria (INTA), Nicolas Repetto y de los Reseros s/n, 1686, Hurlingham, Buenos Aires, Argentina
| | - Carla Antonio
- 1] Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany [2] Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Avenue da República, 2780-157 Oeiras, Portugal
| | - Ronan Sulpice
- 1] System Regulation Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany [2] NUI Galway, Plant Systems Biology Lab, Plant and AgriBiosciences Research Centre, Botany and Plant Science, C311 Aras de Brun, Galway, Ireland
| | - Alisdair R Fernie
- Central Metabolism Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Mark Stitt
- System Regulation Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany
| | - Zoran Nikoloski
- Systems Biology and Mathematical Modeling Group, Max Planck Institute of Molecular Plant Physiology, Am Muehlenberg 1, Potsdam-Golm D-14476, Germany
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67
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Johnstone RA, Kuijper B. Kin competition and the evolution of sex differences in development time and body size. Am Nat 2014; 183:537-46. [PMID: 24642497 DOI: 10.1086/675392] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
One key trade-off underlying life-history evolution is the one between age and size at maturity, with earlier maturation leading to greater chances of juvenile survival at the cost of reduced fecundity as an adult. Here we model the impact of limited dispersal and kin competition on the stable resolution of this trade-off. We show that if mating is at least occasionally nonlocal, then limited dispersal favors juvenile survival over adult fecundity in females, promoting earlier female maturation at the population level; at the same time, it favors adult fecundity over juvenile survival in males, promoting later male maturation. Limited dispersal and local competition can thus drive the evolution of sexual dimorphism in the timing of maturation and consequent dimorphism in body size. At the individual level, if maturation can be flexibly adjusted in response to dispersal status, then both males and females who disperse as offspring should mature earlier than those who remain on their natal patch.
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Affiliation(s)
- Rufus A Johnstone
- Behaviour and Evolution Group, Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, United Kingdom
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68
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Differences in tolerance to host cactus alkaloids in Drosophila koepferae and D. buzzatii. PLoS One 2014; 9:e88370. [PMID: 24520377 PMCID: PMC3919786 DOI: 10.1371/journal.pone.0088370] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/07/2014] [Indexed: 11/19/2022] Open
Abstract
The evolution of cactophily in the genus Drosophila was a major ecological transition involving over a hundred species in the Americas that acquired the capacity to cope with a variety of toxic metabolites evolved as feeding deterrents in Cactaceae. D. buzzatii and D. koepferae are sibling cactophilic species in the D. repleta group. The former is mainly associated with the relatively toxic-free habitat offered by prickly pears (Opuntia sulphurea) and the latter has evolved the ability to use columnar cacti of the genera Trichocereus and Cereus that contain an array of alkaloid secondary compounds. We assessed the effects of cactus alkaloids on fitness-related traits and evaluated the ability of D. buzzatii and D. koepferae to exploit an artificial novel toxic host. Larvae of both species were raised in laboratory culture media to which we added increasing doses of an alkaloid fraction extracted from the columnar cactus T. terschekii. In addition, we evaluated performance on an artificial novel host by rearing larvae in a seminatural medium that combined the nutritional quality of O. sulphurea plus amounts of alkaloids found in fresh T. terschekii. Performance scores in each rearing treatment were calculated using an index that took into account viability, developmental time, and adult body size. Only D. buzzatii suffered the effects of increasing doses of alkaloids and the artificial host impaired viability in D. koepferae, but did not affect performance in D. buzzatii. These results provide the first direct evidence that alkaloids are key determinants of host plant use in these species. However, the results regarding the artificial novel host suggest that the effects of alkaloids on performance are not straightforward as D. koepferae was heavily affected. We discuss these results in the light of patterns of host plan evolution in the Drosophila repleta group.
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69
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Anderson JT, Lee CR, Mitchell-Olds T. Strong selection genome-wide enhances fitness trade-offs across environments and episodes of selection. Evolution 2014; 68:16-31. [PMID: 24102539 PMCID: PMC3928097 DOI: 10.1111/evo.12259] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Accepted: 08/16/2013] [Indexed: 12/12/2022]
Abstract
Fitness trade-offs across episodes of selection and environments influence life-history evolution and adaptive population divergence. Documenting these trade-offs remains challenging as selection can vary in magnitude and direction through time and space. Here, we evaluate fitness trade-offs at the levels of the whole organism and the quantitative trait locus (QTL) in a multiyear field study of Boechera stricta (Brassicaceae), a genetically tractable mustard native to the Rocky Mountains. Reciprocal local adaptation was pronounced for viability, but not for reproductive components of fitness. Instead, local genomes had a fecundity advantage only in the high latitude garden. By estimating realized selection coefficients from individual-level data on viability and reproductive success and permuting the data to infer significance, we examined the genetic basis of fitness trade-offs. This analytical approach (Conditional Neutrality-Antagonistic Pleiotropy, CNAP) identified genetic trade-offs at a flowering phenology QTL (costs of adaptation) and revealed genetic trade-offs across fitness components (costs of reproduction). These patterns would not have emerged from traditional ANOVA-based QTL mapping. Our analytical framework can be applied to other systems to investigate fitness trade-offs. This task is becoming increasingly important as climate change may alter fitness landscapes, potentially disrupting fitness trade-offs that took many generations to evolve.
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Affiliation(s)
- Jill T Anderson
- Department of Biological Sciences, University of South Carolina, Columbia, South Carolina, 29208.
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70
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Santos-del-Blanco L, Bonser SP, Valladares F, Chambel MR, Climent J. Plasticity in reproduction and growth among 52 range-wide populations of a Mediterranean conifer: adaptive responses to environmental stress. J Evol Biol 2013; 26:1912-24. [DOI: 10.1111/jeb.12187] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Revised: 04/13/2013] [Accepted: 04/15/2013] [Indexed: 11/24/2022]
Affiliation(s)
- L. Santos-del-Blanco
- Department of Forest Ecology and Genetics; INIA-CIFOR; Madrid Spain
- Sustainable Forest Management Research Institute; INIA-University of Valladolid; Palencia Spain
| | - S. P. Bonser
- Evolution & Ecology Research Centre; School of Biological, Earth and Environmental Sciences; The University of New South Wales; Sydney NSW Australia
| | - F. Valladares
- Laboratorio Internacional de Cambio Global LINC-Global; Museo Nacional de Ciencias Naturales; MNCN-CSIC; Madrid Spain
| | - M. R. Chambel
- Department of Forest Ecology and Genetics; INIA-CIFOR; Madrid Spain
| | - J. Climent
- Department of Forest Ecology and Genetics; INIA-CIFOR; Madrid Spain
- Sustainable Forest Management Research Institute; INIA-University of Valladolid; Palencia Spain
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71
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Drury DW, Ehmke RC, Jideonwo VN, Wade MJ. Developmental trajectories and breakdown in F1 interpopulation hybrids of Tribolium castaneum. Ecol Evol 2013; 3:1992-2001. [PMID: 23919145 PMCID: PMC3728940 DOI: 10.1002/ece3.536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Revised: 02/18/2013] [Accepted: 02/20/2013] [Indexed: 11/12/2022] Open
Abstract
When hybrid inviability is an indirect by-product of local adaptation, we expect its degree of severity between pairs of populations to vary and to be sensitive to the environment. While complete reciprocal hybrid inviability is the outcome of the gradual process of local adaptation, it is not representative of the process of accumulation of incompatibility. In the flour beetle, Tribolium castaneum, some pairs of populations exhibit complete, reciprocal F1 hybrid incompatibility while other pairs are fully or partially compatible. We characterize this naturally occurring variation in the degree and timing of expression of the hybrid incompatible phenotype to better understand the number of genes or developmental processes contributing to speciation. We assessed the morphological and developmental variation in four Tribolium castaneum populations and their 12 possible F1 hybrids at each life-history stage from egg to adult. We find that the rate of hybrid larval development is affected in all interpopulation crosses, including those eventually producing viable, fertile adults. Hybrid incompatibility manifests early in development as changes in the duration of instars and diminished success in the transition between instars are relative to the parent populations. Parent populations with similar developmental profiles may produce hybrids with disrupted development. The degree and timing of expression of hybrid inviability depends upon populations crossed, direction of the cross, and environment in which hybrids are raised. Our findings suggest that the coordinated expression of genes involved in transitional periods of development is the underlying cause of hybrid incompatibility in this species.
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72
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Tian-Bi YNT, Jarne P, Konan JNK, Utzinger J, N'Goran EK. Contrasting the distribution of phenotypic and molecular variation in the freshwater snail Biomphalaria pfeifferi, the intermediate host of Schistosoma mansoni. Heredity (Edinb) 2013; 110:466-74. [PMID: 23321708 PMCID: PMC3630815 DOI: 10.1038/hdy.2012.115] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 10/11/2012] [Accepted: 11/26/2012] [Indexed: 11/08/2022] Open
Abstract
Population differentiation was investigated by confronting phenotypic and molecular variation in the highly selfing freshwater snail Biomphalaria pfeifferi, the intermediate host of Schistosoma mansoni. We sampled seven natural populations separated by a few kilometers, and characterized by different habitat regimes (permanent/temporary) and openness (open/closed). A genetic analysis based on five microsatellite markers confirms that B. pfeifferi is a selfer (s≈0.9) and exhibits limited variation within populations. Most pairwise FST were significant indicating marked population structure, though no isolation by distance was detected. Families from the seven populations were monitored under laboratory conditions over two generations (G1 and G2), allowing to record several life-history traits, including growth, fecundity and survival, over 25 weeks. Marked differences were detected among populations for traits expressed early in the life cycle (up to sexual maturity). Age and size at first reproduction had high heritability values, but such a trend was not found for early reproductive traits. In most populations, G1 snails matured later and at a larger size than G2 individuals. Individuals from permanent habitats matured at a smaller size and were more fecund than those from temporary habitats. The mean phenotypic differentiation over all populations (QST) was lower than the mean genetic differentiation (FST), suggesting stabilizing selection. However, no difference was detected between QST and FST for both habitat regime and habitat openness.
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Affiliation(s)
- Y-N T Tian-Bi
- Laboratoire de Génétique, UFR Biosciences, Université Félix Houphouët-Boigny, 22 BP 1106 Abidjan 22, Côte d'Ivoire.
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73
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Hu G, Gu W, Bai Q, Wang B. Estimation of genetic parameters for growth traits in a breeding program for rainbow trout (Oncorhynchus mykiss) in China. GENETICS AND MOLECULAR RESEARCH 2013; 12:1457-67. [DOI: 10.4238/2013.april.26.7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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74
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Olijnyk AM, Nelson WA. Positive phenotypic correlations among life-history traits remain in the absence of differential resource ingestion. Funct Ecol 2012. [DOI: 10.1111/1365-2435.12015] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Adriana M. Olijnyk
- Department of Biology; Queen's University; Biosciences Complex, 116 Barrie St., Kingston ON K7L 3N6; Canada
| | - William A. Nelson
- Department of Biology; Queen's University; Biosciences Complex, 116 Barrie St., Kingston ON K7L 3N6; Canada
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75
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Santos-del-Blanco L, Climent J, González-Martínez SC, Pannell JR. Genetic differentiation for size at first reproduction through male versus female functions in the widespread Mediterranean tree Pinus pinaster. ANNALS OF BOTANY 2012; 110:1449-60. [PMID: 23002272 PMCID: PMC3489151 DOI: 10.1093/aob/mcs210] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 07/17/2012] [Indexed: 05/26/2023]
Abstract
BACKGROUND AND AIMS The study of local adaptation in plant reproductive traits has received substantial attention in short-lived species, but studies conducted on forest trees are scarce. This lack of research on long-lived species represents an important gap in our knowledge, because inferences about selection on the reproduction and life history of short-lived species cannot necessarily be extrapolated to trees. This study considers whether the size for first reproduction is locally adapted across a broad geographical range of the Mediterranean conifer species Pinus pinaster. In particular, the study investigates whether this monoecious species varies genetically among populations in terms of whether individuals start to reproduce through their male function, their female function or both sexual functions simultaneously. Whether differences among populations could be attributed to local adaptation across a climatic gradient is then considered. METHODS Male and female reproduction and growth were measured during early stages of sexual maturity of a P. pinaster common garden comprising 23 populations sampled across the species range. Generalized linear mixed models were used to assess genetic variability of early reproductive life-history traits. Environmental correlations with reproductive life-history traits were tested after controlling for neutral genetic structure provided by 12 nuclear simple sequence repeat markers. KEY RESULTS Trees tended to reproduce first through their male function, at a size (height) that varied little among source populations. The transition to female reproduction was slower, showed higher levels of variability and was negatively correlated with vegetative growth traits. Several female reproductive traits were correlated with a gradient of growth conditions, even after accounting for neutral genetic structure, with populations from more unfavourable sites tending to commence female reproduction at a lower individual size. CONCLUSIONS The study represents the first report of genetic variability among populations for differences in the threshold size for first reproduction between male and female sexual functions in a tree species. The relatively uniform size at which individuals begin reproducing through their male function probably represents the fact that pollen dispersal is also relatively invariant among sites. However, the genetic variability in the timing of female reproduction probably reflects environment-dependent costs of cone production. The results also suggest that early sex allocation in this species might evolve under constraints that do not apply to other conifers.
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76
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Kingsolver JG, Diamond SE, Seiter SA, Higgins JK. Direct and indirect phenotypic selection on developmental trajectories in Manduca sexta. Funct Ecol 2012. [DOI: 10.1111/j.1365-2435.2012.01972.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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77
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Quantitative genetics of immunity and life history under different photoperiods. Heredity (Edinb) 2011; 108:569-76. [PMID: 22187084 DOI: 10.1038/hdy.2011.125] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Insects with complex life-cycles should optimize age and size at maturity during larval development. When inhabiting seasonal environments, organisms have limited reproductive periods and face fundamental decisions: individuals that reach maturity late in season have to either reproduce at a small size or increase their growth rates. Increasing growth rates is costly in insects because of higher juvenile mortality, decreased adult survival or increased susceptibility to parasitism by bacteria and viruses via compromised immune function. Environmental changes such as seasonality can also alter the quantitative genetic architecture. Here, we explore the quantitative genetics of life history and immunity traits under two experimentally induced seasonal environments in the cricket Gryllus bimaculatus. Seasonality affected the life history but not the immune phenotypes. Individuals under decreasing day length developed slower and grew to a bigger size. We found ample additive genetic variance and heritability for components of immunity (haemocyte densities, proPhenoloxidase activity, resistance against Serratia marcescens), and for the life history traits, age and size at maturity. Despite genetic covariance among traits, the structure of G was inconsistent with genetically based trade-off between life history and immune traits (for example, a strong positive genetic correlation between growth rate and haemocyte density was estimated). However, conditional evolvabilities support the idea that genetic covariance structure limits the capacity of individual traits to evolve independently. We found no evidence for G × E interactions arising from the experimentally induced seasonality.
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78
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Soto EM, Goenaga J, Hurtado JP, Hasson E. Oviposition and performance in natural hosts in cactophilic Drosophila. Evol Ecol 2011. [DOI: 10.1007/s10682-011-9531-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
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79
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Sletvold N, Ågren J. Among-population variation in costs of reproduction in the long-lived orchid Gymnadenia conopsea: an experimental study. Oecologia 2011; 167:461-8. [PMID: 21556943 PMCID: PMC3172413 DOI: 10.1007/s00442-011-2006-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 04/19/2011] [Indexed: 11/24/2022]
Abstract
A cost of reproduction in terms of reduced future performance underlies all life-history models, yet costs have been difficult to detect in short-term experiments with long-lived plants. The likelihood of detecting costs should depend on the range of variation in reproductive effort that can be induced, and also on the shape of the cost function across this range, which should be affected by resource availability. Here, we experimentally examined the effects of both reduced and increased fruit production in two populations of the long-lived orchid Gymnadenia conopsea located at sites that differ in length of the growing season. Plants that were prevented from fruiting produced more flowers in the population with a longer growing season, had higher survival in the other population, and grew larger compared to control plants in both populations. Fruit production was pollen-limited in both populations, and increased reproductive investment after supplemental hand-pollination was associated with reduced fecundity the following year. The results demonstrate that the shape of the cost function varies among fitness components, and that costs can be differentially expressed in different populations. They are consistent with the hypothesis that differences in temporal overlap between allocation to reproduction and other functions will induce among-population variation in reproductive costs.
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Affiliation(s)
- Nina Sletvold
- NTNU, Museum of Natural History and Archaeology, 7491 Trondheim, Norway
| | - Jon Ågren
- Plant Ecology and Evolution, Department of Ecology and Genetics, EBC, Uppsala University, Norbyvägen 18 D, 752 36 Uppsala, Sweden
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80
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Haselhorst MSH, Edwards CE, Rubin MJ, Weinig C. Genetic architecture of life history traits and environment-specific trade-offs. Mol Ecol 2011; 20:4042-58. [PMID: 21902746 DOI: 10.1111/j.1365-294x.2011.05227.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Life history theory predicts the evolution of trait combinations that enhance fitness, and the occurrence of trade-offs depends in part on the magnitude of variation in growth rate or acquisition. Using recombinant inbred lines, we examined the genetic architecture of age and size at reproduction across abiotic conditions encountered by cultivars and naturalized populations of Brassica rapa. We found that genotypes are plastic to seasonal setting, such that reproduction was accelerated under conditions encountered by summer annual populations and genetic variances for age at reproduction varied across simulated seasonal settings. Using an acquisition-allocation model, we predicted the likelihood of trade-offs. Consistent with predicted relationships, we observed a trade-off where early maturity is associated with small size at maturity under simulated summer and fall annual conditions but not under winter annual conditions. The trade-off in the summer annual setting was observed despite significant genotypic variation in growth rate, which is often expected to decouple age and size at reproduction because rapidly growing genotypes could mature early and attain a larger size relative to slowly growing genotypes that mature later. The absence of a trade-off in the winter setting is presumably attributable to the absence of genotypic differences in age at reproduction. We observed QTL for age at reproduction that jointly regulated size at reproduction in both the summer and fall annual settings, but these QTL were environment-specific (i.e. different QTL contributed to the trade-off in the fall vs. summer annual settings). Thus, at least some of the genetic mechanisms underlying observed trade-offs differed across environments.
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Affiliation(s)
- Monia S H Haselhorst
- Department of Botany Program in Ecology, 1000 E. University Ave., University of Wyoming, Laramie, WY 82071, USA
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81
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Anderson JT, Lee CR, Mitchell-Olds T. Life-history QTLS and natural selection on flowering time in Boechera stricta, a perennial relative of Arabidopsis. Evolution 2011; 65:771-87. [PMID: 21083662 PMCID: PMC3155413 DOI: 10.1111/j.1558-5646.2010.01175.x] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Plants must precisely time flowering to capitalize on favorable conditions. Although we know a great deal about the genetic basis of flowering phenology in model species under controlled conditions, the genetic architecture of this ecologically important trait is poorly understood in nonmodel organisms. Here, we evaluated the transition from vegetative growth to flowering in Boechera stricta, a perennial relative of Arabidopsis thaliana. We examined flowering time QTLs using 7920 recombinant inbred individuals, across seven laboratory and field environments differing in vernalization, temperature, and photoperiod. Genetic and environmental factors strongly influenced the transition to reproduction. We found directional selection for earlier flowering in the field. In the growth chamber experiment, longer winters accelerated flowering, whereas elevated ambient temperatures delayed flowering. Our analyses identified one large effect QTL (nFT), which influenced flowering time in the laboratory and the probability of flowering in the field. In Montana, homozygotes for the native allele at nFT showed a selective advantage of 6.6%. Nevertheless, we found relatively low correlations between flowering times in the field and the growth chambers. Additionally, we detected flowering-related QTLs in the field that were absent across the full range of laboratory conditions, thus emphasizing the need to conduct experiments in natural environments.
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Affiliation(s)
- Jill T. Anderson
- Institute for Genome Sciences and Policy Department of Biology Duke University P.O. Box 90338 Durham, North Carolina 27708 USA
| | - Cheng-Ruei Lee
- Institute for Genome Sciences and Policy Department of Biology Duke University P.O. Box 90338 Durham, North Carolina 27708 USA
| | - Thomas Mitchell-Olds
- Institute for Genome Sciences and Policy Department of Biology Duke University P.O. Box 90338 Durham, North Carolina 27708 USA
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82
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Hu Y, Zhu F, Wang X, Lei C. Development time and body size in Eupolyphaga sinensis along a latitudinal gradient from China. ENVIRONMENTAL ENTOMOLOGY 2011; 40:1-7. [PMID: 22182604 DOI: 10.1603/en09365] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The responses of organisms to temperature variations may be via short term responses of the phenotype (phenotypic plasticity), or they could involve long-term evolutionary change and adaptation (via selection) to the genotype. These could involve changes to the mean size of the animal or to the thermal reaction norm. We examined the effects of various temperatures (of 22, 25, 28, and 31 °C) on development time, adult body size and preadult survivorship in three populations of the cockroach, Eupolyphaga sinensis (Walker), collected at different latitudes. We found substantial temperature-induced plasticity in development time, body size, and preadult survivorship, indicating that developmental temperatures have strong impacts on growth and life history traits of E. sinensis. Genetic differences for development time, body size, and preadult survivorship were detected among populations, and the three traits exhibited highly significant variations in the responses of different populations to various temperature conditions, indicating genetic differences among populations in terms of thermal reaction norms. We also found that two populations seem to support the beneficial acclimation hypothesis whereas the third mid-latitude population does not. The results are likely because of differences in season length and voltinism, indicating that not only temperature regime but also its interactions with generation time (and development time), voltinism, and season length are likely to have considerable effects on insect development time and body size. Overall, changes in development time, body size, and preadult survivorship in E. sinensis can all be regarded as adaptations to changing thermal regimes.
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Affiliation(s)
- Yuwei Hu
- Hubei Insect Resources Utilization and Sustainable Pest Management Key laboratory, College of Plant Science & Technology, Huazhong Agricultural University, Wuhan 430070, Hubei, China
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83
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Tigreros N, Lewis SM. Direct and correlated responses to artificial selection on sexual size dimorphism in the flour beetle, Tribolium castaneum. J Evol Biol 2011; 24:835-42. [PMID: 21276109 DOI: 10.1111/j.1420-9101.2010.02221.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Sexual size dimorphism (SSD) is a conspicuous yet poorly understood pattern across many organisms. Although artificial selection is an important tool for studying the evolution of SSD, previous studies have applied selection to only a single sex or to both sexes in the same direction. In nature, however, SSD likely arises through sex-specific selection on body size. Here, we use Tribolium castaneum flour beetles to investigate the evolution of SSD by subjecting males and females to sexually antagonistic selection on body size (sexes selected in opposite directions). Additionally, we examined correlated responses to body size selection in larval growth rates and development time. After seven generations, SSD remained unchanged in all selected lines; this observed lack of response to short-term selection may be attributed to evolutionary constraints arising from between-sex body size correlations. Developmental traits showed complex correlated responses under different selection treatments. These results suggest that sex-specific larval development patterns may facilitate the evolution of SSD.
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Affiliation(s)
- N Tigreros
- Department of Biology, Tufts University, Medford, MA, USA.
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84
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Hu Y, Yuan X, Zhu F, Lei C. Development time and size-related traits in the oriental blowfly, Chrysomya megacephala along a latitudinal gradient from China. J Therm Biol 2010. [DOI: 10.1016/j.jtherbio.2010.07.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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85
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Dmitriew C, Blows MW, Rowe L. Ontogenetic change in genetic variance in size depends on growth environment. Am Nat 2010; 175:640-9. [PMID: 20406061 DOI: 10.1086/652470] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Within populations, the amount of environmental and genetic variation present may differ greatly among traits measured at multiple times over ontogeny. Brief periods of food deprivation are often followed by a period of accelerated (compensatory) growth. Early laboratory studies likewise reported a contraction of genetic variance in size as maturation approached. However, studies of wild populations often contradict these laboratory results. One possibility is that environmentally imposed stress is exposing genetic variance not seen in the laboratory. We tested the effect of rearing environment (high or low food) on genetic variance in size traits measured at two ages in the ladybird beetle Harmonia axyridis. A substantial amount of genetic variance was present in all combinations of rearing environment by ontogenetic stage among males. The pattern of change in male variance in mass over ontogeny was of opposite sign in the two food treatments, which may reflect cryptic genetic variance that is apparent only under stress. The proportion of overall variance that was due to additive genetic effects was much lower in females than in males, which suggests that the underlying genetics of female growth trajectories differs from that males. Our experimental design afforded an initial exploration of the genetics of compensatory growth.
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Affiliation(s)
- C Dmitriew
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario M5S 3B2, Canada.
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86
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King EG, Roff DA. Modeling the evolution of phenotypic plasticity in resource allocation in wing-dimorphic insects. Am Nat 2010; 175:702-16. [PMID: 20397908 DOI: 10.1086/652434] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
In nature, resource availability varies spatially and temporally both within and across generations, leading to variation in the amount of energy available to individuals. The optimal allocation strategy can change, depending on the amount of resources available to allocate to life-history functions. If so, selection should favor the evolution of allocation strategies that can respond to variation in environmental resource levels. We address this issue by using two quantitative genetic simulation models in a model system for studying trade-offs, wing-dimorphic insects. Wing dimorphic insects typically exhibit a trade-off in the allocation of resources between migratory ability and reproduction. In our models, we focus on allocation as a genetic trait and model the evolution of phenotypic plasticity in this trait in response to spatiotemporal variation in resource availability. We show that the evolved allocation strategy depends on the predictability of resource levels across time. Specifically, selection favors higher investment in flight under poor conditions in predictable environments and lower investment in unpredictable environments.
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Affiliation(s)
- Elizabeth G King
- Department of Biology, University of California, Riverside, California 92521, USA.
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87
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Tiilikainen R, Nygrén T, Pusenius J, Ruusila V. Variation in Growth Pattern of Male MooseAlces alcesAfter Two Contrasted Periods of Hunting. ANN ZOOL FENN 2010. [DOI: 10.5735/086.047.0301] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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88
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Benesh DP. What are the evolutionary constraints on larval growth in a trophically transmitted parasite? Oecologia 2010; 162:599-608. [PMID: 19921268 PMCID: PMC2821511 DOI: 10.1007/s00442-009-1507-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2009] [Accepted: 10/29/2009] [Indexed: 11/07/2022]
Abstract
For organisms with a complex life cycle, a large larval size is generally beneficial, but it may come at the expense of prolonged development. Individuals that grow fast may avoid this tradeoff and switch habitats at both a larger size and younger age. A fast growth rate itself can be costly, however, as it requires greater resource intake. For parasites, fast larval growth is assumed to increase the likelihood of host death before transmission to the next host occurs. Using the tapeworm Schistocephalus solidus in its copepod first intermediate host, I investigated potential constraints in the parasite’s larval life history. Fast-growing parasites developed infectivity earlier, indicating there is no functional tradeoff between size and developmental time. There was significant growth variation among full-sib worm families, but fast-growing sibships were not characterized by lower host survival or more predation-risky host behavior. Parental investment also had little effect on larval growth rates. The commonly assumed constraints on larval growth and development were not observed in this system, so it remains unclear what prevents worms from exploiting their intermediate hosts more aggressively.
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Affiliation(s)
- Daniel P Benesh
- Department of Evolutionary Ecology, Max-Planck-Institute for Evolutionary Biology, Plön, Germany.
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89
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Nijhout HF, Roff DA, Davidowitz G. Conflicting processes in the evolution of body size and development time. Philos Trans R Soc Lond B Biol Sci 2010; 365:567-75. [PMID: 20083633 DOI: 10.1098/rstb.2009.0249] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Body size and development time of Manduca sexta are both determined by the same set of three developmental-physiological factors. These define a parameter space within which it is possible to analyse and explain how phenotypic change is associated with changes in the underlying factors. Body size and development time are determined by the identical set of underlying factors, so they are not independent, but because the mechanisms by which these factors produce each phenotype are different, the two phenotypes are only weakly correlated, and the correlation is context dependent. We use a mathematical model of this mechanism to explore the association between body size and development time and show that the correlation between these two life-history traits can be positive, zero or negative, depending entirely on where in parameter space a population is located, and on which of the underlying factors has a greater variation. The gradient within this parameter space predicts the unconstrained evolutionary trajectory under directional selection on each trait. Calculations of the gradients for body size and development time revealed that these are nearly orthogonal through much of the parameter space. Therefore, simultaneous directional selection on body size and development time can be neither synergistic nor antagonistic but leads to conflicting selection on the underlying developmental parameters.
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90
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Luo S, Shaw WM, Ashraf J, Murphy CT. TGF-beta Sma/Mab signaling mutations uncouple reproductive aging from somatic aging. PLoS Genet 2009; 5:e1000789. [PMID: 20041217 PMCID: PMC2791159 DOI: 10.1371/journal.pgen.1000789] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Accepted: 11/24/2009] [Indexed: 01/07/2023] Open
Abstract
Female reproductive cessation is one of the earliest age-related declines humans experience, occurring in mid-adulthood. Similarly, Caenorhabditis elegans' reproductive span is short relative to its total life span, with reproduction ceasing about a third into its 15–20 day adulthood. All of the known mutations and treatments that extend C. elegans' reproductive period also regulate longevity, suggesting that reproductive span is normally linked to life span. C. elegans has two canonical TGF-ß signaling pathways. We recently found that the TGF-ß Dauer pathway regulates longevity through the Insulin/IGF-1 Signaling (IIS) pathway; here we show that this pathway has a moderate effect on reproductive span. By contrast, TGF-ß Sma/Mab signaling mutants exhibit a substantially extended reproductive period, more than doubling reproductive span in some cases. Sma/Mab mutations extend reproductive span disproportionately to life span and act independently of known regulators of somatic aging, such as Insulin/IGF-1 Signaling and Dietary Restriction. This is the first discovery of a pathway that regulates reproductive span independently of longevity and the first identification of the TGF-ß Sma/Mab pathway as a regulator of reproductive aging. Our results suggest that longevity and reproductive span regulation can be uncoupled, although they appear to normally be linked through regulatory pathways. Female reproductive cessation is the earliest aging phenotype humans experience, and its importance as a clinical issue is growing as more women opt to have children later in life. While much work has been done to understand the general aging process, little is currently known about the regulation of reproductive aging. Like longevity, the ability to produce progeny with advanced age is likely to be genetically regulated. Thus, understanding the processes that regulate reproductive aging may allow us to address the problems of maternal age-related infertility and birth defects. C. elegans and humans both have long post-reproductive life spans, leaving open the possibility that their reproductive spans might be extendable. C. elegans has been used previously to discover conserved regulators of aging, and here we use worms to identify a new regulator of reproductive aging, a highly conserved TGF-ß signaling pathway. We find that TGF-ß signaling regulates reproductive aging independently of somatic aging. This is the first identification of a pathway that breaks the coupling that normally links the two processes. Our work will provide new insights into the improvement of human fertility and prevention of age-related birth defects, and it has implications for the evolutionary relationship between reproduction and longevity regulation.
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Affiliation(s)
- Shijing Luo
- Lewis-Sigler Institute for Integrative Genomics and Department of Molecular Biology, Princeton University, Princeton, New Jersey, USA
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91
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Nespolo RF, Halkett F, Figueroa CC, Plantegenest M, Simon JC. EVOLUTION OF TRADE-OFFS BETWEEN SEXUAL AND ASEXUAL PHASES AND THE ROLE OF REPRODUCTIVE PLASTICITY IN THE GENETIC ARCHITECTURE OF APHID LIFE HISTORIES. Evolution 2009; 63:2402-12. [DOI: 10.1111/j.1558-5646.2009.00706.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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92
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Jaramillo J, Chabi-Olaye A, Kamonjo C, Jaramillo A, Vega FE, Poehling HM, Borgemeister C. Thermal tolerance of the coffee berry borer Hypothenemus hampei: predictions of climate change impact on a tropical insect pest. PLoS One 2009; 4:e6487. [PMID: 19649255 PMCID: PMC2715104 DOI: 10.1371/journal.pone.0006487] [Citation(s) in RCA: 122] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2009] [Accepted: 06/17/2009] [Indexed: 11/21/2022] Open
Abstract
Coffee is predicted to be severely affected by climate change. We determined the thermal tolerance of the coffee berry borer , Hypothenemus hampei, the most devastating pest of coffee worldwide, and make inferences on the possible effects of climate change using climatic data from Colombia, Kenya, Tanzania, and Ethiopia. For this, the effect of eight temperature regimes (15, 20, 23, 25, 27, 30, 33 and 35°C) on the bionomics of H. hampei was studied. Successful egg to adult development occurred between 20–30°C. Using linear regression and a modified Logan model, the lower and upper thresholds for development were estimated at 14.9 and 32°C, respectively. In Kenya and Colombia, the number of pest generations per year was considerably and positively correlated with the warming tolerance. Analysing 32 years of climatic data from Jimma (Ethiopia) revealed that before 1984 it was too cold for H. hampei to complete even one generation per year, but thereafter, because of rising temperatures in the area, 1–2 generations per year/coffee season could be completed. Calculated data on warming tolerance and thermal safety margins of H. hampei for the three East African locations showed considerably high variability compared to the Colombian site. The model indicates that for every 1°C rise in thermal optimum (Topt.), the maximum intrinsic rate of increase (rmax) will increase by an average of 8.5%. The effects of climate change on the further range of H. hampei distribution and possible adaption strategies are discussed. Abstracts in Spanish and French are provided as supplementary material Abstract S1 and Abstract S2.
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Affiliation(s)
- Juliana Jaramillo
- Institute of Plant Diseases and Plant Protection, University of Hannover, Hannover, Germany.
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93
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Abstract
Sex allocation is a crucial life-history parameter in all sexual organisms. Over the last decades a body of evolutionary theory, sex allocation theory, was developed, which has yielded capital insight into the evolution of optimal sex allocation patterns and adaptive evolution in general. Most empirical work, however, has focused on species with separate sexes. Here I review sex allocation theory for simultaneous hermaphrodites and summarize over 50 empirical studies, which have aimed at evaluating this theory in a diversity of simultaneous hermaphrodites spanning nine animal phyla. These studies have yielded considerable qualitative support for several predictions of sex allocation theory, such as a female-biased sex allocation when the number of mates is limited, and a shift toward a more male-biased sex allocation with increasing numbers of mates. In contrast, many fundamental assumptions, such as the trade-off between male and female allocation, and numerous predictions, such as brooding limiting the returns from female allocation, are still poorly supported. Measuring sex allocation in simultaneously hermaphroditic animals remains experimentally demanding, which renders evaluation of more quantitative predictions a challenging task. I identify the main questions that need to be addressed and point to promising avenues for future research.
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Affiliation(s)
- Lukas Schärer
- University of Basel, Zoological Institute, Evolutionary Biology, Vesalgasse 1, 4051 Basel, Switzerland.
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94
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Vorburger C, Ramsauer N. Genetic variation and covariation of aphid life-history traits across unrelated host plants. BULLETIN OF ENTOMOLOGICAL RESEARCH 2008; 98:543-553. [PMID: 18590593 DOI: 10.1017/s0007485308005853] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A central paradigm of life-history theory is the existence of resource mediated trade-offs among different traits that contribute to fitness, yet observations inconsistent with this tenet are not uncommon. We previously found a clonal population of the aphid Myzus persicae to exhibit positive genetic correlations among major components of fitness, resulting in strong heritable fitness differences on a common host. This raises the question of how this genetic variation is maintained. One hypothesis states that variation for resource acquisition on different hosts may override variation for allocation, predicting strong fitness differences within hosts as a rule, but changes in fitness hierarchies across hosts due to trade-offs. Therefore, we carried out a life-table experiment with 17 clones of M. persicae, reared on three unrelated host plants: radish, common lambsquarters and black nightshade. We estimated the broad-sense heritabilities of six life-history traits on each host, the genetic correlations among traits within hosts, and the genetic correlations among traits on different hosts (cross-environment genetic correlations). The three plants represented radically different environments with strong effects on performance of M. persicae, yet we detected little evidence for trade-offs. Fitness components were positively correlated within hosts but also between the two more benign hosts (radish and lambsquarters), as well as between those and another host tested earlier. The comparison with the most stressful host, nightshade, was hampered by low survival. Survival on nightshade also exhibited genetic variation but was unrelated to fitness on other hosts. Acknowledging that the number of environments was necessarily limited in a quantitative genetic experiment, we suggest that the rather consistent fitness hierarchies across very different plants provided little evidence to support the idea that the clonal variation for life-history traits and their covariance structure are maintained by strong genotypexenvironment interactions with respect to hosts. Alternative explanations are discussed.
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Affiliation(s)
- C Vorburger
- Institute of Zoology, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
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95
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Jones ME, Cockburn A, Hamede R, Hawkins C, Hesterman H, Lachish S, Mann D, McCallum H, Pemberton D. Life-history change in disease-ravaged Tasmanian devil populations. Proc Natl Acad Sci U S A 2008; 105:10023-7. [PMID: 18626026 PMCID: PMC2481324 DOI: 10.1073/pnas.0711236105] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Indexed: 11/18/2022] Open
Abstract
Changes in life history are expected when new sources of extrinsic mortality impact on natural populations. We report a new disease, devil facial tumor disease, causing an abrupt transition from iteroparity toward single breeding in the largest extant carnivorous marsupial, the Tasmanian devil (Sarcophilus harrisii), in which males can weigh as much as 14 kg and females 9 kg. This change in life history is associated with almost complete mortality of individuals from this infectious cancer past their first year of adult life. Devils have shown their capacity to respond to this disease-induced increased adult mortality with a 16-fold increase in the proportion of individuals exhibiting precocious sexual maturity. These patterns are documented in five populations where there are data from before and after disease arrival and subsequent population impacts. To our knowledge, this is the first known case of infectious disease leading to increased early reproduction in a mammal. The persistence of both this disease and the associated life-history changes pose questions about longer-term evolutionary responses and conservation prospects for this iconic species.
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Affiliation(s)
- Menna E Jones
- School of Zoology, University of Tasmania, Hobart TAS 7001, Australia.
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96
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Hautekèete NC, Piquot Y, Van Dijk H. Investment in survival and reproduction along a semelparity-iteroparity gradient in theBetaspecies complex. J Evol Biol 2008. [DOI: 10.1046/j.1420-9101.2001.00322.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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97
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Engqvist L. Environment-dependent genetic correlations between development time and body mass in a scorpionfly. ZOOLOGY 2007; 110:344-53. [PMID: 17888643 DOI: 10.1016/j.zool.2007.07.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2007] [Revised: 07/09/2007] [Accepted: 07/19/2007] [Indexed: 10/22/2022]
Abstract
Development time and body mass at maturation are two important fitness traits fundamental for our understanding of life history theory. Generally, fast development is associated with small adult body mass, as it will take longer to grow large. However, the strength of this trade-off may depend on average food availability, as the potential benefit of long development will depend on the rate of food intake. Here, I report results of a food manipulation experiment during larval development of the scorpionfly Panorpa cognata (Insecta, Mecoptera). Development time showed considerable genetic variation, yet food level had no influence and there was a strong genetic correlation in development time across environments. As expected, larval and adult body weight was significantly affected by food availability. Furthermore, body mass was influenced by a highly significant genotype-by-environment interaction. The reaction norm for body mass in response to food treatment was much stronger in families with long development time compared with rapidly developing genotypes. This effect was accompanied by a shift in the genetic correlation between development time and body size when comparing the two food levels. Specifically, the genetic correlation between body mass and development time changed from being positive at high food levels to a negative genetic correlation at low food levels. These results are consistent with other empirical findings demonstrating a similar shift in genetic correlations between body mass and development time when comparing favourable and unfavourable environmental conditions.
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Affiliation(s)
- Leif Engqvist
- Department of Evolutionary Biology and Ecology, University of Bonn, An der Immenburg 1, D-53121, Bonn, Germany.
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98
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Sargent RD, Goodwillie C, Kalisz S, Ree RH. Phylogenetic evidence for a flower size and number trade-off. AMERICAN JOURNAL OF BOTANY 2007; 94:2059-2062. [PMID: 21636399 DOI: 10.3732/ajb.94.12.2059] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The size and number of flowers displayed together on an inflorescence (floral display) influences pollinator attraction and pollen transfer and receipt, and is integral to plant reproductive success and fitness. Life history theory predicts that the evolution of floral display is constrained by trade-offs between the size and number of flowers and inflorescences. Indeed, a trade-off between flower size and flower number is a key assumption of models of inflorescence architecture and the evolution of floral display. Surprisingly, however, empirical evidence for the trade-off is limited. In particular, there is a lack of phylogenetic evidence for a trade-off between flower size and number. Analyses of phylogenetic independent contrasts (PICs) of 251 angiosperm species spanning 63 families yielded a significant negative correlation between flower size and flower number. At smaller phylogenetic scales, analyses of individual genera did not always find evidence of a trade-off, a result consistent with previous studies that have examined the trade-off for a single species or genus. Ours is the first study to support an angiosperm-wide trade-off between flower size and number and supports the theory that life history constraints have influenced the evolution of floral display.
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Affiliation(s)
- Risa D Sargent
- Department of Integrative Biology, University of California, Berkeley, California 94720-3140 USA
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99
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Montague JL, Barrett SCH, Eckert CG. Re-establishment of clinal variation in flowering time among introduced populations of purple loosestrife (Lythrum salicaria, Lythraceae). J Evol Biol 2007; 21:234-245. [PMID: 18028354 DOI: 10.1111/j.1420-9101.2007.01456.x] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Range expansion during biological invasion requires that invaders adapt to geographical variation in climate, which should yield latitudinal clines in reproductive phenology. We investigated geographic variation in life history among 25 introduced populations of Lythrum salicaria, a widespread European invader of North American wetlands. We detected a strong latitudinal cline in initiation of flowering and size at flowering, which paralleled that reported among native populations. Plants from higher latitudes flowered earlier and at a smaller size than those from lower latitudes, even when raised in a uniform glasshouse. Early flowering was associated with greatly reduced reproductive output, but this was not associated with latitudinal variation in abundance, and probably did not result from a genetic correlation between time to and size at flowering. As introduction to North America c. 200 years ago, L. salicaria has re-established latitudinal clines in life history, probably as an evolutionary response to climatic selection.
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Affiliation(s)
- J L Montague
- Department of Biology, Queen's University, Kingston, ON, CanadaDepartment of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - S C H Barrett
- Department of Biology, Queen's University, Kingston, ON, CanadaDepartment of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
| | - C G Eckert
- Department of Biology, Queen's University, Kingston, ON, CanadaDepartment of Ecology and Evolutionary Biology, University of Toronto, Toronto, ON, Canada
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100
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Cheplick GP. Growth trajectories and size-dependent reproduction in the highly invasive grass Microstegium vimineum. Biol Invasions 2007. [DOI: 10.1007/s10530-007-9170-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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