The Experts below are selected from a list of 1611 Experts worldwide ranked by ideXlab platform
Lars Gustafsson - One of the best experts on this subject based on the ideXlab platform.
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quantitative genetics of the use of conspecific and heterospecific social cues for breeding site choice
Evolution, 2020Co-Authors: Jere Tolvanen, Sami M Kivela, Piter Bijma, Velimatti Pakanen, Blandine Doligez, Lars Gustafsson, Jennifer MorinayAbstract:Social information use for decision-making is common and affects ecological and evolutionary processes, including social aggregation, species coexistence, and cultural evolution. Despite increasing ecological knowledge on social information use, very little is known about its genetic basis and therefore its evolutionary potential. Genetic variation in a trait affecting an individual's social and nonsocial environment may have important implications for population dynamics, interspecific interactions, and, for expression of other, environmentally plastic traits. We estimated repeatability, additive genetic variance, and heritability of the use of conspecific and heterospecific social cues (abundance and breeding success) for breeding site choice in a population of wild collared flycatchers Ficedula albicollis. Repeatability was found for two social cues: previous year conspecific breeding success and previous year heterospecific abundance. Yet, additive genetic variances for these two social cues, and thus heritabilities, were low. This suggests that most of the phenotypic variation in the use of social cues and resulting conspecific and heterospecific social environment experienced by individuals in this population stems from phenotypic plasticity. Given the important role of social information use on ecological and evolutionary processes, more studies on genetic versus environmental determinism of social information use are needed.
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silver spoon upbringing improves early life fitness but promotes reproductive ageing in a wild bird
Ecology Letters, 2020Co-Authors: Foteini Spagopoulou, Lars Gustafsson, Celine Teplitsky, Martin I Lind, Alexei A Maklakov, Stephane ChantepieAbstract:Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use a long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment (artificially reduced broods) have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment (artificially increased broods). Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from a higher mortality rate. Our results demonstrate that 'silver-spoon' natal conditions increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings demonstrate experimentally that natal environment shapes individual variation in reproductive and actuarial ageing in nature.
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silver spoon upbringing improves early life fitness but promotes reproductive ageing in a wild bird
bioRxiv, 2019Co-Authors: Foteini Spagopoulou, Lars Gustafsson, Celine Teplitsky, Martin I Lind, Alexei A MaklakovAbstract:Summary Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use a long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment (artificially reduced broods) have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment (artificially increased broods). Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from a higher mortality rate. Our results demonstrate that “silver-spoon” natal conditions increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings demonstrate experimentally that natal environment shapes individual variation in reproductive and demographic ageing in nature.
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Transient growth-enhancing effects of elevated maternal thyroid hormones at no apparent oxidative cost during early postnatal period
Journal of Avian Biology, 2019Co-Authors: Bin-yan Hsu, Lars Gustafsson, Blandine Doligez, Suvi RuuskanenAbstract:Maternal thyroid hormones (THs) have been proven crucial for embryonic development in humans, but their influence within the natural variation on wild animals remains unknown. So far the only two studies that experimentally investigated the potential fitness consequences of maternal THs in birds found inconsistent results. More studies are thus required to assess the general effects of maternal THs and their influences on more behavioral and physiological parameters. In this study, we experimentally elevated yolk TH content in a wild migratory passerine species, the collared flycatcher Ficedula albicollis, to investigate the effects on hatching success, nestling growth and oxidative stress. We found that TH-injected eggs had a higher hatching success, and the nestlings hatched from TH-injected eggs were heavier and larger than control nestlings, but only during the early postnatal period. These differences vanished by fledging. Nestlings from TH-injected eggs exhibited lower activity of the glutathione-s-transferase, a major antioxidant enzyme, than control nestlings at day 12, a few days before fledging, but they did not differ in oxidative damage and overall intracellular oxidative state. These results suggest that the early growth-enhancing effects incurred no observable oxidative stress. We hypothesize that such a transient growth-enhancing effect might be adaptive in advancing the development and maturation of the offspring so they are well-prepared in time for the upcoming migration. Further studies investigating whether such advancing effects can influence long-term fitness, will be more than valuable.
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Sex-biased gene expression, sexual antagonism and levels of genetic diversity in the collared flycatcher (Ficedula albicollis) genome
Molecular ecology, 2018Co-Authors: Ludovic Dutoit, Lars Gustafsson, Carina F Mugal, Paulina Bolivar, Mi Wang, Krystyna Nadachowska-brzyska, Linnéa Smeds, Homa Papoli Yazdi, Hans EllegrenAbstract:Theoretical work suggests that sexual conflict should promote the maintenance of genetic diversity by the opposing directions of selection on males and females. If such conflict is pervasive, it could potentially lead to genomic heterogeneity in levels of genetic diversity an idea that so far has not been empirically tested on a genomewide scale. We used large-scale population genomic and transcriptomic data from the collared flycatcher (Ficedula albicollis) to analyse how sexual conflict, for which we use sex-biased gene expression as a proxy, relates to genetic variability. Here, we demonstrate that the extent of sex-biased gene expression of both male-biased and female-biased genes is significantly correlated with levels of nucleotide diversity in gene sequences and that this correlation extends to diversity levels also in intergenic DNA and introns. We find signatures of balancing selection in sex-biased genes but also note that relaxed purifying selection could potentially explain part of the observed patterns. The finding of significant genetic differentiation between males and females for male-biased (and gonad-specific) genes indicates ongoing sexual conflict and sex-specific viability selection, potentially driven by sexual selection. Our results thus indicate that sexual antagonism could potentially be considered as one viable explanation to the long-standing question in evolutionary biology of how genomes can remain so genetically variable in face of strong natural and sexual selection.
János Török - One of the best experts on this subject based on the ideXlab platform.
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triparental care in the collared flycatcher Ficedula albicollis cooperation of two females with a cuckolded male in rearing a brood
Ecology and Evolution, 2021Co-Authors: Miklós Laczi, János Török, Balázs Rosivall, Renata Kopena, Fanni Sarkadi, Dora Kotel, Gergely HegyiAbstract:Certain predominant forms of mating and parental care systems are assumed in several model species among birds, but the opportunistic and apparently infrequent variations of "family structures" may often remain hidden due to methodological limitations with regard to genetic or behavioral observations. One of the intensively studied model species, the collared flycatcher (Ficedula albicollis), is usually characterized by social monogamy with polyterritorial, facultative social polygyny, and frequent extrapair mating and extrapair paternity. During a brood-size manipulation experiment, we observed two females and a male delivering food at an enlarged brood. A combination of breeding phenology data (egg laying and hatching date), behavioral data (feeding rates) from video recordings at 10 days of nestling age, and microsatellite genotyping for maternity and paternity suggests a situation of an unrelated female helping a pair in chick rearing. Such observations highlight the relevance of using traditional techniques and genetic analyses together to assess the parental roles within a population, which becomes more important where individuals may dynamically switch from their main and presupposed roles according to the actual environmental conditions.
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escape ability and risk taking behaviour in a hungarian population of the collared flycatcher Ficedula albicollis
Behavioral Ecology and Sociobiology, 2017Co-Authors: Mónika Jablonszky, János Török, Eszter Szász, Gábor Markó, Gabor Herczeg, László Zsolt GaramszegiAbstract:Risk-taking decisions in front of a predator are crucial for the fitness of the animals. Risk-taking behaviour can be hypothesised to depend on escape ability, which is difficult to study in the wild. In this field study, we investigated whether escape ability (i) is a consistent individual-specific characteristic and (ii) can explain between-individual variation in risk-taking behaviour in male collared flycatchers (Ficedula albicollis). We estimated escape ability by the time that was needed to capture individuals by hand in an outdoor aviary during both the courtship and the nestling feeding phases. We estimated risk-taking by human-induced flight initiation distance (FID) and parental nest-defence behaviour. We also measured variables that reflect individual quality and condition to assess how these affect escape ability. Time to capture was weakly repeatable in the within- and between-season contexts, but was considerably repeatable within a day. We found that time to capture decreased between courtship and nestling feeding phases, probably due to parallel changes in body condition (as shown by the systematic decline of individual body mass between phases correlating with within-individual changes in time to capture). Overall, time to capture was not significantly related to risk-taking behaviour, but we found a negative correlation between time to capture and FID in yearlings. In conclusion, escape ability in flycatchers seems to be a condition-dependent plastic trait, and it has the potential to affect immediate risk-taking decisions. We investigated the proximate determinants of escape ability in collared flycatcher males and whether this trait can be a potential driver of risk-taking behaviour, which is a rarely considered issue. We measured escape ability as time needed to capture birds in an outdoor aviary by hand. We found that escape ability was repeatable only in a short-term context, and differed between the courtship and chick-feeding periods, probably due to parallel changes in body condition. Furthermore, escape ability in yearlings (but not in adults) correlated with an estimate of risk-taking in the wild indicating that males with better ability to escape take higher risk. Our findings highlight that individual decisions about risk-taking might partially rely on how individuals assess their potential escape success.
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haemoproteus infection status of collared flycatcher males changes within a breeding season
Parasitology Research, 2016Co-Authors: Eszter Szöllősi, Gergely Hegyi, Miklós Laczi, Balázs Rosivall, László Zsolt Garamszegi, János TörökAbstract:In ecological studies of haemosporidian parasites, prevalence is typically considered as a stable attribute. However, little is known about the possible within-host dynamics of these parasites that may originate from environmental fluctuations, parasite life cycles and the ability of hosts to suppress or clear infection. We sampled the blood of male collared flycatchers Ficedula albicollis twice within a breeding season and investigated the determinants of initial infection status and change in infection status. We found that older males tended to be initially more infected at courtship. Change in infection status was unrelated to male traits, but a widespread disappearance of Haemoproteus pallidus infection from the blood was detected between courtship and nestling rearing. The probability of change in infection status increased with the time elapsed between sampling occasions. This suggests that the disappearance of infection from the blood was due to either an active parasite suppression mechanism or the beginning of the latent phase in the parasite life cycle. Initial infection status or disappearance of infection from the blood showed no correlation with breeding success. These results show that H. pallidus infection status and thus prevalence are dynamically changing attributes and this has widespread practical and ecological implications.
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Laying date and polygyny as determinants of annual reproductive success in male collared flycatchers (Ficedula albicollis): a long-term study
Naturwissenschaften, 2014Co-Authors: Marton Herenyi, Rita Hargitai, Gergely Hegyi, Balázs Rosivall, Eszter Szöllősi, László Zsolt Garamszegi, János TörökAbstract:Annual reproductive success (ARS) is one of the main components of lifetime reproductive success, a reliable measure of individual fitness. Previous studies often dealt with ARS and variables potentially affecting it. Among them, long-term studies that consider multiple factors at the same time are particularly important in understanding the adaptive value of different phenotypes. Here, we used an 18-year dataset to quantify the ARS of male collared flycatchers ( Ficedula albicollis ) on the basis of recruited offspring. We simultaneously assessed the effect of start of breeding, age, polygyny, body size and the expression of forehead patch (a sexually selected trait). The success of early breeding individuals was appreciably higher than late birds; however, breeding too early was also disadvantaged, and males that bred around the yearly median breeding date had the highest ARS. Polygynous males were more successful in years with good food supply, while in years with low food availability, they did not produce more recruits than monogamous males. The age of males, their forehead patch size and body size did not affect the number of recruits. Our findings support the importance of breeding date and suggest stabilizing selection on it in the long term. We also show that polygyny is not always advantageous for males, and its fitness pay-off may depend on environmental quality.
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the relationship between syllable repertoire similarity and pairing success in a passerine bird species with complex song
Journal of Theoretical Biology, 2012Co-Authors: László Zsolt Garamszegi, Sandor Zsebok, János TörökAbstract:Abstract Repertoire size, i.e. the number of unique song elements that an individual possesses, is thought to be an important target of female preference. However, the use of repertoire size reflects how researchers work with complex songs; while it does not necessary describe biological functions, as listeners of song may also rely on song composition. Specific syllables may have coherent consequences for mate attraction because they are costly to produce, mediate syllable sharing or indicate the dialect of origin. We tested for the relationship between song composition and pairing success in the collared flycatcher ( Ficedula albicollis ). We applied a tree-clustering method to hierarchically classify males based on the degree of repertoire overlap, and then used a phylogenetic approach to assess the degree by which pairing speed matches the hierarchically structured song data. We found that males using similar syllables also find a breeding partner at a similar speed. Partitioning the variance components of pairing speed, we detected that the consequences of particular syllables for mating are repeatable across males. When assessing the role of repertoire similarity in mediating direct syllable sharing, we derived a positive relationship between the physical distance between pairs of males and their repertoire overlap implying that neighboring males avoid copying each other's song. Finally, we were unable to demonstrate that syllables related to higher mating success are more common in the population, which would support mechanisms based on female preference for local songs. Our results imply that individual-specific song organization may be relevant for sexual selection.
Hans Ellegren - One of the best experts on this subject based on the ideXlab platform.
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Sex-biased gene expression, sexual antagonism and levels of genetic diversity in the collared flycatcher (Ficedula albicollis) genome
Molecular ecology, 2018Co-Authors: Ludovic Dutoit, Lars Gustafsson, Carina F Mugal, Paulina Bolivar, Mi Wang, Krystyna Nadachowska-brzyska, Linnéa Smeds, Homa Papoli Yazdi, Hans EllegrenAbstract:Theoretical work suggests that sexual conflict should promote the maintenance of genetic diversity by the opposing directions of selection on males and females. If such conflict is pervasive, it could potentially lead to genomic heterogeneity in levels of genetic diversity an idea that so far has not been empirically tested on a genomewide scale. We used large-scale population genomic and transcriptomic data from the collared flycatcher (Ficedula albicollis) to analyse how sexual conflict, for which we use sex-biased gene expression as a proxy, relates to genetic variability. Here, we demonstrate that the extent of sex-biased gene expression of both male-biased and female-biased genes is significantly correlated with levels of nucleotide diversity in gene sequences and that this correlation extends to diversity levels also in intergenic DNA and introns. We find signatures of balancing selection in sex-biased genes but also note that relaxed purifying selection could potentially explain part of the observed patterns. The finding of significant genetic differentiation between males and females for male-biased (and gonad-specific) genes indicates ongoing sexual conflict and sex-specific viability selection, potentially driven by sexual selection. Our results thus indicate that sexual antagonism could potentially be considered as one viable explanation to the long-standing question in evolutionary biology of how genomes can remain so genetically variable in face of strong natural and sexual selection.
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genomic distribution and estimation of nucleotide diversity in natural populations perspectives from the collared flycatcher Ficedula albicollis genome
Molecular Ecology Resources, 2017Co-Authors: Ludovic Dutoit, Reto Burri, Carina F Mugal, Alexander Nater, Hans EllegrenAbstract:Properly estimating genetic diversity in populations of nonmodel species requires a basic understanding of how diversity is distributed across the genome and among individuals. To this end, we anal ...
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quantitative genetics of sexual size dimorphism in the collared flycatcher Ficedula albicollis
Evolution, 1998Co-Authors: Juha Merila, Ben C Sheldon, Hans EllegrenAbstract:Quantitative genetic theory predicts that evolution of sexual size dimorphism (SSD) will be a slow process if the genetic correlation in size between the sexes is close to unity, and the heritability of size is similar in both sexes. However, there are very few reliable estimates of genetic correlations and sex-specific heritabilities from natural populations, the reasons for this being that (1) offspring have often been sexed retrospectively, and hence, selection acting differently with respect to body size in the two sexes between measuring and sex identification can bias estimates of SSD; and (2) in many taxa, parents may be incorrectly assigned to offspring either because of assignment errors or because of extrapair paternity. We used molecular sex and paternity identification to overcome these problems and estimated sex-specific heritabilities and the genetic correlation in body size between the two sexes in the collared flycatcher, Ficedula albicollis. After exclusion of the illegitimate offspring, the genetic correlation in body size between the sexes was 1.00 (SE = 0.22), implying a severe constraint on the evolution of SSD in this species. Furthermore, sex-specific heritability estimates were very similar, indicating that neither sex will be able to evolve faster than the other. By using estimated genetic parameters, together with empirically derived estimates of sex-specific selection gradients, we further demonstrated that the predicted selection response in female tarsus length is displaced about 200% in the opposite direction from that to be expected if there were no genetic correlation between the sexes. The correspondence between the biochemically estimated rate of extrapair paternity (about 15 % of the young) and that estimated from the "heritability method" (11%) was good. However, the estimated rate of extrapair paternity with the heritability method after exclusion of the illegitimate young was 22%, adding to increasing evidence that factors other than extrapair paternity (e.g., maternal effects) may be resposible for the commonly observed higher mother- offspring than father-offspring resemblance.
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paternal genetic contribution to offspring condition predicted by size of male secondary sexual character
Proceedings of The Royal Society B: Biological Sciences, 1997Co-Authors: Lars Gustafsson, Anna Qvarnstrom, Juha Merila, Ben C Sheldon, Hans EllegrenAbstract:Whether females can obtain genetic benefits from mate choice is contentious, and the main problem faced by previous studies of natural populations is that many factors other than paternal genes contribute to offspring fitness. Here, we use comparisons between sets of naturally occurring maternal half-sibling collared flycatchers, Ficedula albicollis, to control for this problem. We show, first, that there are paternal genetic effects on nestling fledging condition, a character related to fitness in this species. Further, the magnitude of the paternal genetic contribution to this character is related to the size of a condition-dependent male secondary sexual character. Our results demonstrate that genetic benefits from mate choice can be predicted by the size of a secondary sexual character, and therefore provide direct support for indicator models of sexual selection.
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sex ratio adjustment in relation to paternal attractiveness in a wild bird population
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Hans Ellegren, Lars Gustafsson, Ben C SheldonAbstract:Abstract When the relative fitness of sons and daughters differs, sex-allocation theory predicts that it would be adaptive for individuals to adjust their investment in different sexes of offspring. Sex ratio adjustment by females in response to the sexual attractiveness of their mate would be an example of this. In vertebrates the existence of this form of sex ratio adjustment is controversial and may be confounded with sex-biased mortality, particularly in sexually size-dimorphic species. Here we use PCR amplification of a conserved W-chromosome-linked gene to show that the sex ratio within broods of a natural population of sexually size-monomorphic collared flycatchers Ficedula albicollis is related to the size of their father's forehead patch, a heritable secondary sexual character implicated in female choice. Experimental manipulations of paternal investment, which influence the size of his character in future breeding attempts, result in corresponding changes in the sex ratio of offspring born to males in those breeding attempts. In contrast, manipulations of maternal investment have no effect on future sex ratios, and there is no relationship between variables predicting the reproductive value of the brood and nestling sex ratio. Analysis of recruitment of offspring reveals similar patterns of sex ratio bias. The results suggest that female collared flycatchers be able to adjust the sex ratio of eggs ovulated in response to the phenotype of their mate. This finding is most consistent with "genetic quality" models of sexual selection.
Ben C Sheldon - One of the best experts on this subject based on the ideXlab platform.
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divergent patterns of age dependence in ornamental and reproductive traits in the collared flycatcher
Evolution, 2011Co-Authors: Simon R Evans, Lars Gustafsson, Ben C SheldonAbstract:Sexual ornaments are predicted to honestly signal individual condition. We might therefore expect ornament expression to show a senescent decline, in parallel with late-life deterioration of other characters. Conversely, life-history theory predicts the reduced residual reproductive value of older individuals will favor increased investment in sexually attractive traits. Using a 25-year dataset of more than 5000 records of breeding collared flycatchers (Ficedula albicollis) of known age, we quantify cross-sectional patterns of age-dependence in ornamental plumage traits and report long-term declines in expression that mask highly significant positive age-dependency. We partition this population-level age-dependency into its between- and within-individual components and show expression of ornamental white plumage patches exhibits within-individual increases with age in both sexes, consistent with life-history theory. For males, ornament expression also covaries with life span, such that, within a cohort, ornamentation indicates survival. Finally, we compared longitudinal age-dependency of reproductive traits and ornamental traits in both sexes, to assess whether these two trait types exhibit similar age-dependency. These analyses revealed contrasting patterns: reproductive traits showed within-individual declines in late-life females consistent with senescence; ornamental traits showed the opposite pattern in both males and females. Hence, our results for both sexes suggest that age-dependent ornament expression is consistent with life-history models of optimal signaling and, unlike reproductive traits, proof against senescence.
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natural selection and inheritance of breeding time and clutch size in the collared flycatcher
Evolution, 2003Co-Authors: Loeske E B Kruuk, Ben C Sheldon, Juha MerilaAbstract:Abstract Many characteristics of organisms in free-living populations appear to be under directional selection, possess additive genetic variance, and yet show no evolutionary response to selection. Avian breeding time and clutch size are often-cited examples of such characters. We report analyses of inheritance of, and selection on, these traits in a long-term study of a wild population of the collared flycatcher Ficedula albicollis. We used mixed model analysis with REML estimation (“animal models”) to make full use of the information in complex multigenerational pedigrees. Heritability of laying date, but not clutch size, was lower than that estimated previously using parent-offspring regressions, although for both traits there was evidence of substantial additive genetic variance (h2 = 0.19 and 0.29, respectively). Laying date and clutch size were negatively genetically correlated (rA = −0.41 ± 0.09), implying that selection on one of the traits would cause a correlated response in the other, but ther...
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severe inbreeding depression in collared flycatchers Ficedula albicollis
Proceedings of The Royal Society B: Biological Sciences, 2002Co-Authors: Loeske E B Kruuk, Juha Merila, Ben C SheldonAbstract:The causes and magnitude of inbreeding depression are of considerable importance for a wide range of issues in evolutionary and conservation biology, but we have only a limited understanding of inbreeding depression in natural populations. Here, we present a study of inbreeding in a large wild population of collared flycatchers ( Ficedula albicollis ). Inbreeding was rare, to the extent that we detected only 1.04%of 2139 matings over 18 years that resulted in offspring with a non–zero inbreeding coefficient, f > 0. When it did occur, inbreeding caused a significant reduction in the egg–hatching rate, in fledgling skeletal size and in post–fledging juvenile survival, with the number of offspring being recruited to the breeding population from a nest of f = 0.25 being reduced by 94% relative to a non–inbred nest. A maximum–likelihood estimate of the number of lethal equivalents per gamete was very high at B = 7.47, indicating a substantial genetic load in this population. There was also a non–significant tendency for inbreeding depression to increase with the strength of selection on a trait. The probability of mating between close relatives f = 0.25) increased throughout the breeding season, possibly reflecting increased costs of inbreeding avoidance. Our results illustrate how severe inbreeding depression and considerable genetic load may exist in natural populations, but detecting them may require extensive long–term datasets.
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experimental analysis of sperm competition mechanisms in a wild bird population
Proceedings of the National Academy of Sciences of the United States of America, 2002Co-Authors: Gábor Michl, János Török, Simon C Griffith, Ben C SheldonAbstract:Recent work on wild birds has revealed the importance of sperm competition as a source of sexual selection, but behavioral and paternity studies have previously provided only indirect evidence for mechanisms of sperm competition in wild birds. In a field study of collared flycatchers Ficedula albicollis we used a previously uncharacterized method to determine the frequency and timing of extra-pair inseminations. By counting the number of sperm trapped on the perivitelline layer of eggs, we determined the timing of inseminations and estimated, on a day-to-day basis, the amount of sperm females stored. Our results showed that female collared flycatchers preferentially engaged in extra-pair copulations when mated to an unattractive male with a small white forehead patch. These copulations were timed for the middle part of their fertile period, at least 2 days after the last within-pair insemination. Although the mean number of extra-pair insemination events was only 1.33 per cuckolding female, the ratio between the number of sperm from extra-pair and pair inseminations was at least 5 to 1. Thus a single, well timed extra-pair insemination caused by female behavior could greatly bias fertilization probability in favor of an attractive extra-pair male. Our results suggest a possible behavioral mechanism for female control of sperm competition.
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phenotypic selection on a heritable size trait revisited
The American Naturalist, 2001Co-Authors: Loeske E B Kruuk, Juha Merila, Ben C SheldonAbstract:Abstract: One of evolutionary biology’s most persistent puzzles is the fact that apparent directional selection on a heritable trait in a natural population often does not produce a selection response. We tested three possible explanations for this problem using data on body size of more than 23,000 individuals, measured over 18 yr, in a collared flycatcher (Ficedula albicollis) population. Using a restricted maximum likelihood “animal model,” we found a narrow‐sense heritability for fledgling tarsus length of \documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage[OT2,OT1]{fontenc} \newcommand\cyr{ \renewcommand\rmdefault{wncyr} \renewcommand\sfdefault{wncyss} \renewcommand\encodingdefault{OT2} \normalfont \selectfont} \DeclareTextFontCommand{\textcyr}{\cyr} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6}...
Alexei A Maklakov - One of the best experts on this subject based on the ideXlab platform.
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silver spoon upbringing improves early life fitness but promotes reproductive ageing in a wild bird
Ecology Letters, 2020Co-Authors: Foteini Spagopoulou, Lars Gustafsson, Celine Teplitsky, Martin I Lind, Alexei A Maklakov, Stephane ChantepieAbstract:Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use a long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment (artificially reduced broods) have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment (artificially increased broods). Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from a higher mortality rate. Our results demonstrate that 'silver-spoon' natal conditions increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings demonstrate experimentally that natal environment shapes individual variation in reproductive and actuarial ageing in nature.
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silver spoon upbringing improves early life fitness but promotes reproductive ageing in a wild bird
bioRxiv, 2019Co-Authors: Foteini Spagopoulou, Lars Gustafsson, Celine Teplitsky, Martin I Lind, Alexei A MaklakovAbstract:Summary Early-life conditions can have long-lasting effects and organisms that experience a poor start in life are often expected to age at a faster rate. Alternatively, individuals raised in high-quality environments can overinvest in early-reproduction resulting in rapid ageing. Here we use a long-term experimental manipulation of early-life conditions in a natural population of collared flycatchers (Ficedula albicollis), to show that females raised in a low-competition environment (artificially reduced broods) have higher early-life reproduction but lower late-life reproduction than females raised in high-competition environment (artificially increased broods). Reproductive success of high-competition females peaked in late-life, when low-competition females were already in steep reproductive decline and suffered from a higher mortality rate. Our results demonstrate that “silver-spoon” natal conditions increase female early-life performance at the cost of faster reproductive ageing and increased late-life mortality. These findings demonstrate experimentally that natal environment shapes individual variation in reproductive and demographic ageing in nature.