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1.
High Educ (Dordr) ; : 1-21, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37362752

RESUMO

This study explores dissatisfaction and neutrality metrics from 12 years of a national-level undergraduate student survey. The notion of dissatisfaction is much less prevalent in the narratives surrounding student survey outcomes, and the underpinning metrics are seldom considered. This is despite an increasingly vociferous debate about 'value for money' of higher education and the positioning of students as consumers in a marketised sector. We used machine learning methods to explore over 2.7 million national survey outcomes from 154 institutions to describe year-on-year stability in the survey items that best predicted dissatisfaction and neutrality, together with their similarity to known metric predictors of satisfaction. The widely publicised annual increases in student 'satisfaction' are shown to be the result of complex reductions in the proportions of disagreement and neutrality across different survey dimensions. Due to the widespread use of survey metrics in university league tables, we create an anonymised, illustrative table to demonstrate how UK institutional rankings would have differed if dissatisfaction metrics had been the preferred focus for reporting. We conclude by debating the tensions of balancing the provision of valuable information about dissatisfaction, with perpetuating negative impacts that derive from this important subset of the survey population.

2.
Nurs Inq ; 26(3): e12294, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31056831

RESUMO

The early withdrawal of students from healthcare education programmes, particularly nursing, is an international concern and, despite considerable investment, retention rates have remained stagnant. Here, a regional study of healthcare student retention is used as an example to frame the challenge of student attrition using a concept from policy development, wicked problem theory. This approach allows the consideration of student attrition as a complex problem derived from the interactions of many interrelated factors, avoiding the pitfalls of small-scale interventions and over-simplistic assumptions of cause and effect. A conceptual framework is proposed to provide an approach to developing actions to reduce recurrent investment in interventions that have previously proved ineffective at large scale. We discuss how improvements could be achieved through integrated stakeholder involvement and acceptance of the wicked nature of attrition as a complex and ongoing problem.


Assuntos
Evasão Escolar/estatística & dados numéricos , Estudantes de Ciências da Saúde/estatística & dados numéricos , Atenção à Saúde/normas , Atenção à Saúde/tendências , Humanos , Evasão Escolar/psicologia , Estudantes de Ciências da Saúde/psicologia , Inquéritos e Questionários , Universidades/organização & administração , Universidades/estatística & dados numéricos
3.
J Clin Nurs ; 27(5-6): 929-938, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28815761

RESUMO

AIMS AND OBJECTIVES: To explore the perceived unfairness experienced by student nurses during their undergraduate clinical placements. BACKGROUND: It is important that student nurses feel supported by practice staff during their clinical placement education experiences. However, it has been reported that learners can feel ignored, unsupported and bullied by others in the clinical environment and this has a detrimental effect on their learning. It is important to understand the student nurse perspective and explore ways in which their feelings of belongingness might be enhanced in the clinical area. DESIGN: A descriptive narrative approach was used to explore the qualitative data generated by the survey and interviews. Limited closed-question survey data were acquired to explore a selection of quantified survey responses about placements and mentorship. METHODS: A survey was conducted with 1,425 student nurses from adult and mental health degree nursing pathways, across nine institutions in the North West of England, UK. Unstructured interviews were undertaken with 22 student nurses from across these nine institutions. The data generated from both methods (free-text survey responses and interview) were thematically analysed. RESULTS: There were times when student nurses felt that they had been treated unfairly by various members of the healthcare team during their clinical placements. Unfairness was related to being ignored and unsupported or being used as an "extra pair of hands" and having their supernumerary status ignored. Student nurses want to have feelings of belongingness in the clinical area and value enthusiasm for teaching from mentors. Certain positive mentor qualities were identified through the data in this study. These have been used to inform a tiered model of mentorship, to inform future thinking about student nurse education. CONCLUSION: Student nurses can feel like they are being treated unfairly in the clinical area in numerous ways. Identifying ways in which mentorship practice can be developed to adequately support education is important. This can lead to satisfaction and development on both sides of the student/educator relationship. RELEVANCE TO PRACTICE: Exploring student nurse perceptions of their learning is important when attempting to enhance educational practice in the clinical setting.


Assuntos
Bacharelado em Enfermagem/organização & administração , Relações Interpessoais , Mentores , Estudantes de Enfermagem/psicologia , Adulto , Atitude do Pessoal de Saúde , Bacharelado em Enfermagem/métodos , Inglaterra , Feminino , Humanos , Masculino , Percepção , Pesquisa Qualitativa , Inquéritos e Questionários
4.
PLoS One ; 17(5): e0268238, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35622824

RESUMO

As dairy cows are being housed for longer periods, with all-year-round housing growing in popularity, it is important to ensure housed environments are meeting the needs of cows. Dairy cows are motivated to access open lying areas, although previous motivation studies on this topic have confounded surface type and location (i.e. pasture outdoors vs cubicles indoors). This study measured cow motivation for lying down on an indoor open mattress (MAT; 9 m x 5 m) compared to indoor mattress-bedded cubicles, thus removing the confounding factor of surface type and location. This was repeated for an identically sized indoor deep-bedded straw yard (ST), to investigate whether surface type affected motivation for an open lying area. Thirty Holstein-Friesian dairy cows were housed in groups of 5 (n = 5 x 6) in an indoor robotic milking unit with access to six mattress-bedded cubicles. To assess motivation, cows were required to walk increasing distances via a one-way indoor raceway to access the open lying areas: Short (34.5 m), followed by Medium (80.5 m) and Long (126.5 m). Cows could choose to walk the raceway, leading to the MAT or ST, to lie down or they could lie down on the cubicles for 'free'. Overall, cows lay down for longer on the open lying areas at each distance compared to the cubicles, with cows lying down slightly longer on ST than MAT, although lying times on the open lying areas did decrease at the Long distance. However, cows were still lying for >60% of their lying time on the open lying areas at the Long distance. This study demonstrates that cows had a high motivation for an open lying area, the provision of which could better cater for the behavioural needs of housed dairy cows and improve housed dairy cow welfare.


Assuntos
Comportamento Animal , Abrigo para Animais , Animais , Bovinos , Feminino , Leite , Motivação
5.
PeerJ ; 9: e10798, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33665014

RESUMO

BACKGROUND: High altitude insects are an ecologically specialized group and possess a suite of adaptions which allow persistence in the inhospitable conditions often associated with mountain tops. Changes in body coloration and reductions or increases in body size are thought to be examples of such adaptions. Melanic individuals, or individuals containing high levels of eumelanin, possess several traits which increase resistance to ultraviolet radiation and desiccation, while aiding thermoregulation. Trait variation is often observed in dung beetles and is associated with dimorphism and sexual selection. In this study, we identified trait changes which occur across an altitudinal gradient by measuring morphological color and body size traits in a montane insect. METHODS: Using standard digital photography and Image J, we examined individuals of Afromontane dung beetle Onthophagus proteus. Individuals were classified according to sex and color morph to identify intrasexual variance. Nine morphometric traits were measured per beetle to identify patterns of morphology across discrete 500 m altitude segments. RESULTS: The results of this study provide one of the first descriptions of trait changes associated with elevation in an African dung beetle. We suggest that color polymorphism in Onthophagus proteus might be at least partly driven by environmental factors as there is significantly increased melanism with increasing elevation and significant differences in color hues between altitude bands. We also suggest changes in horn length are density dependent, as we observed an increase in cephalic horn length at high elevations where O. proteus is the most abundant species.

6.
Mol Ecol Resour ; 19(6): 1672-1680, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31339632

RESUMO

Bespoke microsatellite marker panels are increasingly affordable and tractable to researchers and conservationists. The rate of microsatellite discovery is very high within a shotgun genomic data set, but extensive laboratory testing of markers is required for confirmation of amplification and polymorphism. By incorporating shotgun next-generation sequencing data sets from multiple individuals of the same species, we have developed a new method for the optimal design of microsatellite markers. This new tool allows us to increase the rate at which suitable candidate markers are selected by 58% in direct comparisons and facilitate an estimated 16% reduction in costs associated with producing a novel microsatellite panel. Our method enables the visualisation of each microsatellite locus in a multiple sequence alignment allowing several important quality checks to be made. Polymorphic loci can be identified and prioritised. Loci containing fragment-length-altering mutations in the flanking regions, which may invalidate assumptions regarding the model of evolution underlying variation at the microsatellite, can be avoided. Priming regions containing point mutations can be detected and avoided, helping to reduce sample-site-marker specificity arising from genetic isolation, and the likelihood of null alleles occurring. We demonstrate the utility of this new approach in two species: an echinoderm and a bird. Our method makes a valuable contribution towards minimising genotyping errors and reducing costs associated with developing a novel marker panel. The Python script to perform our method of multi-individual microsatellite identification (MiMi) is freely available from GitHub (https://github.com/graemefox/mimi).


Assuntos
Genoma/genética , Repetições de Microssatélites/genética , Alelos , Marcadores Genéticos/genética , Genômica/métodos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação Puntual/genética , Polimorfismo Genético/genética
7.
Hum Mutat ; 29(12): 1405-11, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18561327

RESUMO

Hair morphology differs dramatically between human populations: people of East Asian ancestry typically have a coarse hair texture, with individual fibers being straight, of large diameter, and cylindrical when compared to hair of European or African origin. Ectodysplasin-A receptor (EDAR) is a cell surface receptor of the tumor necrosis factor receptor (TNFR) family involved in the development of hair follicles, teeth, and sweat glands. Analyses of genome-wide polymorphism data from multiple human populations suggest that EDAR experienced strong positive selection in East Asians. It is likely that a nonsynonymous SNP in EDAR, rs3827760, was the direct target of selection as the derived p.Val370Ala variant is seen at high frequencies in populations of East Asian and Native American origin but is essentially absent from European and African populations. Here we demonstrate that the derived EDAR370A common in East Asia has a more potent signaling output than the ancestral EDAR370 V in vitro. We show that elevation of Edar activity in transgenic mice converts their hair phenotype to the typical East Asian morphology. The coat texture becomes coarse, with straightening and thickening of individual hairs and conversion of fiber cross-sectional profile to a circular form. These thick hair fibers are produced by enlarged hair follicles, which in turn develop from enlarged embryonic organ primordia. This work shows that the multiple differences in hair form between East Asian and other human populations can be explained by the simplest of genetic alterations.


Assuntos
Povo Asiático/genética , Receptor Edar/genética , Receptor Edar/metabolismo , Cabelo/química , Polimorfismo de Nucleotídeo Único , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Linhagem Celular , Receptor Edar/química , Cabelo/metabolismo , Humanos , Camundongos , Camundongos Transgênicos , Alinhamento de Sequência
8.
Evolution ; 62(2): 337-47, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18031305

RESUMO

The paradoxical persistence of heritable variation for fitness-related traits is an evolutionary conundrum that remains a preeminent problem in evolutionary biology. Here we describe a simple mechanism in which social competition results in the evolutionary maintenance of heritable variation for fitness related traits. We demonstrate this mechanism using a genetic model with two primary assumptions: the expression of a trait depends upon success in social competition for limited resources; and competitive success of a genotype depends on the genotypes that it competes against. We find that such social competition generates heritable (additive) genetic variation for "competition-dependent" traits. This heritable variation is not eroded by continuous directional selection because, rather than leading to fixation of favored alleles, selection leads instead to allele frequency cycling due to the concerted coevolution of the social environment with the effects of alleles. Our results provide a mechanism for the maintenance of heritable variation in natural populations and suggest an area for research into the importance of competition in the genetic architecture of fitness related traits.


Assuntos
Comportamento Animal , Comportamento Competitivo , Variação Genética , Alelos , Animais , Evolução Biológica , Evolução Molecular , Genética Comportamental , Genótipo , Modelos Biológicos , Modelos Genéticos , Modelos Estatísticos
9.
Bone Joint Res ; 7(10): 570-579, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30464837

RESUMO

AIMS: Calcium sulphate has traditionally been used as a filler of dead space arising during surgery. Various complications have been described following the use of Stimulan bio-absorbable calcium sulphate beads. This study is a prospective observational study to assess the safety profile of these beads when used in revision arthroplasty, comparing the complication rates with those reported in the literature. METHODS: A total of 755 patients who underwent 456 revision total knee arthroplasties (TKA) and 299 revision total hip arthroplasties (THA), with a mean follow-up of 35 months (0 to 78) were included in the study. RESULTS: A total of 32 patients (4.2%) had wound drainage, and this was higher with higher bead volumes and in McPherson grade C patients. There was also a significantly higher bead volume in the 41 patients who developed hypercalcaemia, two of which were symptomatic (p < 0.0001). A total of 13 patients (1.7%) had heterotopic ossification (HO). There was no statistically significant relationship between the development of HO and bead volume (p > 0.05). CONCLUSION: The strength of this study lies in the large number of patients and the detailed data collection, making it the most comprehensive report available in the literature on the use of calcium sulphate-based bone substitutes.Cite this article: R. Kallala, W. Edwin Harris, M. Ibrahim, M. Dipane, E. McPherson. Use of Stimulan absorbable calcium sulphate beads in revision lower limb arthroplasty: Safety profile and complication rates. Bone Joint Res 2018;7:570-579. DOI: 10.1302/2046-3758.710.BJR-2017-0319.R1.

10.
Am Nat ; 169(3): 311-22, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17243076

RESUMO

In many species, females abandon mate choice to ensure that eggs are fertilized before they are lost. But why do females not just maintain oocytes longer if there is a benefit to mate choice? We conducted a quantitative genetic study in the cockroach Nauphoeta cinerea to test whether genetic constraints prevent the evolution of oocyte maintenance or selection against oocyte loss is weak when females mate late relative to sexual maturity. We found standing genetic variation within the population and no evidence for genetic constraints. Levels of genetic variation are of the magnitude found for life-history traits in general, suggesting that this trait has been exposed to selection. We unexpectedly found two categories of females: those that delay reproduction and those that reproduce at a normal time when mating late, which could indicate alternative strategies. However, frequency-dependent selection does not maintain this variation as females that delay always reproduce less well. Given these findings, we suggest that there may be advantages to egg degradation. The evolution of maintenance of fertilizable oocytes over time would then be constrained by the need to maintain the mechanism by which females control the distribution of resources between current and future reproductive events.


Assuntos
Evolução Biológica , Baratas/genética , Variação Genética , Oogênese/genética , Seleção Genética , Maturidade Sexual/genética , Análise de Variância , Animais , Baratas/fisiologia , Feminino , Aptidão Genética , Masculino , Casamento
11.
PLoS One ; 11(5): e0153908, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27166624

RESUMO

Demographic data are important to wildlife managers to gauge population health, to allow populations to be utilised sustainably, and to inform conservation efforts. We analysed published demographic data on the world's wildfowl to examine taxonomic and geographic biases in study, and to identify gaps in knowledge. Wildfowl (order: Anseriformes) are a comparatively well studied bird group which includes 169 species of duck, goose and swan. In all, 1,586 wildfowl research papers published between 1911 and 2010 were found using Web of Knowledge (WoK) and Google Scholar. Over half of the research output involved just 15 species from seven genera. Research output was strongly biased towards 'high income' countries, common wildfowl species, and measures of productivity, rather than survival and movement patterns. There were significantly fewer demographic data for the world's 31 threatened wildfowl species than for non-threatened species. Since 1994, the volume of demographic work on threatened species has increased more than for non-threatened species, but still makes up only 2.7% of total research output. As an aid to research prioritisation, a metric was created to reflect demographic knowledge gaps for each species related to research output for the species, its threat status, and availability of potentially useful surrogate data from congeneric species. According to the metric, the 25 highest priority species include thirteen threatened taxa and nine species each from Asia and South America, and six from Africa.


Assuntos
Anseriformes/fisiologia , Conservação dos Recursos Naturais , Espécies em Perigo de Extinção , Viés de Publicação/estatística & dados numéricos , África , Animais , Animais Selvagens , Anseriformes/classificação , Ásia , Bibliometria , Biodiversidade , Dinâmica Populacional , América do Sul
12.
Am Nat ; 165 Suppl 5: S64-71, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15795863

RESUMO

Different aspects of male quality as a mate can vary independently. When this is the case, females may need to use multiple cues to accurately assess overall mate quality. We examined the pattern of mating preference in the cockroach Nauphoeta cinerea. Sexual conflict occurs in this species because male manipulation of female mating receptivity can result in reduced female fitness. We predicted that since females cannot remate within a single reproductive bout because of male manipulation, females should assess male mating history to avoid mating with males with low fertility caused by sperm exhaustion. In a mate-preference experiment, we found that females discriminated against males who had mated multiple times. Females also discriminated against males who had consorted with several females but had been prevented from mating with those females. Thus, females appeared to be able to detect cues on males that were derived from previous mates and to use this information to avoid mating with sperm-exhausted males. We suggest that females may commonly use multiple cues to assess different aspects of mate quality, especially when male quality changes over time. This is an under-studied phenomenon that could help explain individual variation in female mating preferences.


Assuntos
Baratas/fisiologia , Conflito Psicológico , Preferência de Acasalamento Animal/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Odorantes , Reprodução/fisiologia
13.
Evolution ; 58(8): 1773-80, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15446429

RESUMO

Ejaculates function as an integrated unit to ensure male fertility and paternity, can have a complex structure, and can experience multiple episodes of selection. Current studies on the evolution of ejaculates typically focus on phenotypic variation in sperm number, size, or related traits such as testes size as adaptations to postcopulatory male-male competition. However, the evolution of the integrated nature of ejaculate structure and function depends on genetic variation in and covariation between the component parts. Here we report a quantitative genetic study of the components of the ejaculate of the cockroach Nauphoeta cinerea, including those we know to experience postcopulatory sexual selection, in the context of functional integration of ejaculate characters. We use the patterns of genetic variation and covariation to infer how the integration of the functions of the ejaculate constrain and shape its evolution. Ejaculate components were highly variable, showed significant additive genetic variance, and moderate to high evolvability. The level of genetic variation in these characters, despite strong directional or truncating selection, may reflect the integration of multiple episodes of selection that occur in N. cinerea. There were few significant phenotypic correlations, but all the genetic correlations among ejaculate characters were significantly different from zero. The patterns of genetic variation and covariation suggest that there are important trade-offs among individual traits of the ejaculate and that evolution of ejaculate characteristics will not proceed unconstrained. Fully describing the genetic relationships among traits that perform as an integrated unit helps us understand how functional relationships constrain or facilitate the evolution of the complex structure that is the ejaculate.


Assuntos
Evolução Biológica , Baratas/fisiologia , Variação Genética , Seleção Genética , Sêmen/química , Espermatozoides/fisiologia , Análise de Variância , Animais , Baratas/genética , Feminino , Genitália Masculina/anatomia & histologia , Masculino , Característica Quantitativa Herdável
14.
Proc Biol Sci ; 270 Suppl 2: S192-4, 2003 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-14667380

RESUMO

Recent studies in two species of Drosophila have demonstrated a negative effect of parental age on offspring fitness, including a reduced hatch rate of eggs and larval-to-adult viability. This has led to a call to consider the decline of offspring quality as a function of parental age in theoretical considerations of the evolution of ageing. We have tested whether a decline in egg and larval quality of older mothers is a general feature of senescence by examining it in the cockroach Nauphoeta cinerea. We also tested whether maternal age affected the reproductive potential of daughters. Although maternal age at first reproduction profoundly affected maternal fitness, there was no difference in hatch rate or larval viability between the offspring of young and old mothers. Likewise, the reproductive potential of the daughters of young and old mothers was the same. Thus, while maternal age effects may be important aspects of ageing in some systems, the generality and overall importance for theories of ageing remain unclear.


Assuntos
Envelhecimento/fisiologia , Baratas/fisiologia , Idade Materna , Análise de Variância , Animais , Feminino , Fertilidade/fisiologia
15.
J Am Coll Surg ; 210(3): 325-30, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20193896

RESUMO

BACKGROUND: Double-gloving in the performance of surgical procedures has been demonstrated to reduce the frequency of blood contact with the hands of members of the surgical team. Concerns persist that double-gloving can compromise the dexterity and tactile sensitivity of the surgeon. STUDY DESIGN: Fifty-three surgeons and surgeons-in-training volunteered at the Clinical Congress of the American College of Surgeons and were studied using the Purdue Pegboard test and a standard 2-point discrimination test to compare no gloves, a single pair of gloves, and double-gloving on manual dexterity and tactile sensitivity. Categorical and continuous variables were identified, general linear prediction models were computed, and the influence of glove status was analyzed as an independent variable. Monte Carlo simulation was employed to validate conclusions. RESULTS: Gender, specialty, and handedness did not affect prediction models. Glove status did not affect dexterity performance scores (p = 0.57) after accounting for the influence of age on score variation (p < 0.001). Comparing ulnar and radial surfaces of the index finger for 2-point discrimination, no difference was detected between trials (p < 0.66), nor was an interaction effect detected with glove status (p = 0.40). Monte Carlo simulations validated the apparent absence of differences. CONCLUSIONS: Double-gloving does not have a substantial impact on manual dexterity or tactile sensitivity when compared with no gloves or single-gloving in this study.


Assuntos
Luvas Cirúrgicas , Mãos/fisiologia , Destreza Motora , Procedimentos Cirúrgicos Operatórios , Tato , Patógenos Transmitidos pelo Sangue , Infecção Hospitalar/prevenção & controle , Feminino , Humanos , Modelos Lineares , Masculino , Método de Monte Carlo , Análise e Desempenho de Tarefas
16.
Philos Trans R Soc Lond B Biol Sci ; 364(1520): 1039-48, 2009 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-19324609

RESUMO

Reproductive investment decisions form an integral part of life-history biology. Selection frequently favours plasticity in investment that can generate maternal effects on offspring development. For example, if females differentially allocate resources based on mate attractiveness or quality, this can create a non-genetic link between mate attractiveness and offspring fitness with potential consequences for ecological and evolutionary dynamics. It is therefore important to understand under what conditions differential investment into offspring in relation to male quality is expected to occur and the direction of the effect. Two opposite predictions, increased investment into offspring produced with high-quality mates (differential allocation (DA)) and increased investment with low-quality males (reproductive compensation (RC)) have been suggested but no formal theoretical treatment justifying the assumptions underlying these two hypotheses has been conducted to date. Here, we used a state-based approach to investigate the circumstances under which the variation in mate quality results in differential female investment into offspring and how this interacts with female energetic resource levels. We found that a pattern of increased investment when mating with high-quality mates (i.e. DA) was the most common optimal investment strategy for females in our model. By contrast, increased investment when mating with low-quality mates (i.e. RC) was predicted only when the relative impact of parental investment on offspring quality was low. Finally, we found that the specific pattern of investment in relation to male quality depends on female energetic state, the likelihood for future mating opportunities and the expected future distribution of mate quality. Thus, the female's age and body condition should be important factors mediating DA and RC, which may help to explain the equivocal results of empirical studies.


Assuntos
Preferência de Acasalamento Animal , Reprodução/fisiologia , Comportamento Sexual Animal , Animais , Cruzamento , Comportamento de Escolha/fisiologia , Feminino , Masculino , Comportamento Materno/fisiologia , Modelos Biológicos , Modelos Psicológicos , Método de Monte Carlo , Seleção de Pacientes , Probabilidade , Seleção Genética
17.
Genetica ; 134(1): 89-97, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17924196

RESUMO

In theory, females of many species choose mates based on traits that are indicators of male genetic quality. A fundamental question in evolutionary biology is why genetic variation for such indicator traits persists despite strong persistent selection imposed by female preference, which is known as the lek paradox. One potential solution to the lek paradox suggests that the traits that are targets of mate choice should evolve condition-dependent expression and that condition should have a large genetic variance. Condition is expected to exhibit high genetic variance because it is affected by a large number of physiological processes and hence, condition-dependent traits should 'capture' variation contributed by a large number of loci. We suggest that a potentially important cause of variation in condition is competition for limited resources. Here, we discuss a pair of models to analyze the evolutionary genetics of traits affected by success in social competition for resources. We show that competition can contribute to genetic variation of 'competition-dependent' traits that have fundamentally different evolutionary properties than other sources of variation. Competition dependence can make traits honest indicators of genetic quality by revealing the relative competitive ability of males, can provide a component of heritable variation that does not contribute to trait evolution, and can help maintain heritable variation under directional selection. Here we provide a general introduction to the concept of competition dependence and briefly introduce two models to demonstrate the potential evolutionary consequences of competition-dependent trait expression.


Assuntos
Comportamento Competitivo , Evolução Molecular , Variação Genética , Animais , Comportamento Animal , Feminino , Genética Comportamental , Masculino , Modelos Genéticos
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