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Geoffrey Parker - One of the best experts on this subject based on the ideXlab platform.
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Clutch Size, fecundity and parent-offspring conflict
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 1991Co-Authors: H. C. J. Godfray, Geoffrey ParkerAbstract:Selection often acts in different ways on genes expressed in parents and offspring leading to parent—offspring conflict. The effect of parent—offspring conflict on the evolution of reproductive strategies is explored. Models are constructed using kin-selection techniques and it is argued that these are frequently more useful than techniques from classical population genetics. Parent and offspring optima are compared in models of (1) the trade-off between the number and Size of offspring, (2) Clutch Size and (3) the evolution of reproductive effort with age structure. Parent—offspring conflict over Clutch Size is examined in more detail. Models of sibling competition are reviewed and it is suggested that the reduction in parental fitness caused by sibling competition may lead to selection on Clutch Size. The possibility that the parent may be selected to produce a hierarchy of Sizes of young in order to reduce sibling conflict is investigated. The preliminary results give little support for this hypothesis. An extreme form of sibling conflict, siblicide, is also discussed. In some cases, the kin-selection approach fails in the analysis of siblicide and classical population genetic models are required. The paper concludes that parent—offspring conflict is a potentially significant, and often overlooked, factor influencing the evolution of reproductive strategies. Birds in their little nests agree And ’tis a shameful sight, When children of one family Fall out, and chide, and fight Isaac Watts, Love between Brothers & Sisters , 1721. Birds in their little nests agree With Chinamen, but not with me. Hilaire Belloc, On Food .
Hanna Kokko - One of the best experts on this subject based on the ideXlab platform.
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The Evolution of Clutch Size in Hosts of Avian Brood Parasites.
The American naturalist, 2017Co-Authors: Iliana Medina, Naomi E. Langmore, Robert Lanfear, Hanna KokkoAbstract:Coevolution with avian brood parasites shapes a range of traits in their hosts, including morphology, behavior, and breeding systems. Here we explore whether brood parasitism is also associated with the evolution of host Clutch Size. Several studies have proposed that hosts of highly virulent parasites could decrease the costs of parasitism by evolving a smaller Clutch Size, because hosts with smaller Clutches will lose fewer progeny when their Clutch is parasitized. We describe a model of the evolution of Clutch Size, which challenges this logic and shows instead that an increase in Clutch Size (or no change) should evolve in hosts. We test this prediction using a broad-scale comparative analysis to ask whether there are differences in Clutch Size within hosts and between hosts and nonhosts. Consistent with our model, this analysis revealed that host species do not have smaller Clutches and that hosts that incur larger costs from raising a parasite lay larger Clutches. We suggest that brood parasitism might be an influential factor in Clutch-Size evolution and could potentially select for the evolution of larger Clutches in host species.
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the evolution of Clutch Size in hosts of avian brood parasites
The American Naturalist, 2017Co-Authors: Iliana Medina, Naomi E. Langmore, Robert Lanfear, Hanna KokkoAbstract:AbstractCoevolution with avian brood parasites shapes a range of traits in their hosts, including morphology, behavior, and breeding systems. Here we explore whether brood parasitism is also associated with the evolution of host Clutch Size. Several studies have proposed that hosts of highly virulent parasites could decrease the costs of parasitism by evolving a smaller Clutch Size, because hosts with smaller Clutches will lose fewer progeny when their Clutch is parasitized. We describe a model of the evolution of Clutch Size, which challenges this logic and shows instead that an increase in Clutch Size (or no change) should evolve in hosts. We test this prediction using a broad-scale comparative analysis to ask whether there are differences in Clutch Size within hosts and between hosts and nonhosts. Consistent with our model, this analysis revealed that host species do not have smaller Clutches and that hosts that incur larger costs from raising a parasite lay larger Clutches. We suggest that brood paras...
Bruce E Lyon - One of the best experts on this subject based on the ideXlab platform.
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optimal Clutch Size and conspecific brood parasitism
Nature, 1998Co-Authors: Bruce E LyonAbstract:Egg-laying organisms should lay, in a reproductive bout, the number of eggs that maximizes fitness. Lack argued 50 years ago that Clutch Size for most birds is limited by the amount of food parents can provide for their offspring1. Clutch Sizes, however, are often smaller than this ‘Lack Clutch Size’, and this fact is the subject of much debate2,3,4. Here I propose and test a new explanation for this pattern that is based on evidence that conspecific brood parasitism is widespread in birds5,6,7, specifically when females with their own nests also parasitize conspecific birds8,9,10,11,12,13. A graphical model of Clutch Size shows that the trade-offs a brood parasite faces when allocating eggs to her own nest or to nests of other conspecific females can favour a reduction in the parasite's own Clutch Size. This prediction is supported by a field study of American coots (Fulica americana). Moreover, the cost of receiving parasitic eggs also favours a reduction in Clutch Size for hosts, introducing a ‘game’14 element to Clutch Size when parasitic females are themselves parasitized. These results indicate that conspecific brood parasitism should no longer be ignored as a force in Clutch-Size evolution.
H. C. J. Godfray - One of the best experts on this subject based on the ideXlab platform.
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Clutch Size, fecundity and parent-offspring conflict
Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences, 1991Co-Authors: H. C. J. Godfray, Geoffrey ParkerAbstract:Selection often acts in different ways on genes expressed in parents and offspring leading to parent—offspring conflict. The effect of parent—offspring conflict on the evolution of reproductive strategies is explored. Models are constructed using kin-selection techniques and it is argued that these are frequently more useful than techniques from classical population genetics. Parent and offspring optima are compared in models of (1) the trade-off between the number and Size of offspring, (2) Clutch Size and (3) the evolution of reproductive effort with age structure. Parent—offspring conflict over Clutch Size is examined in more detail. Models of sibling competition are reviewed and it is suggested that the reduction in parental fitness caused by sibling competition may lead to selection on Clutch Size. The possibility that the parent may be selected to produce a hierarchy of Sizes of young in order to reduce sibling conflict is investigated. The preliminary results give little support for this hypothesis. An extreme form of sibling conflict, siblicide, is also discussed. In some cases, the kin-selection approach fails in the analysis of siblicide and classical population genetic models are required. The paper concludes that parent—offspring conflict is a potentially significant, and often overlooked, factor influencing the evolution of reproductive strategies. Birds in their little nests agree And ’tis a shameful sight, When children of one family Fall out, and chide, and fight Isaac Watts, Love between Brothers & Sisters , 1721. Birds in their little nests agree With Chinamen, but not with me. Hilaire Belloc, On Food .
Dolph Schluter - One of the best experts on this subject based on the ideXlab platform.
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TIME, CONDITION, AND THE SEASONAL DECLINE OF AVIAN Clutch Size
The American Naturalist, 1994Co-Authors: Locke Rowe, Donald Ludwig, Dolph SchluterAbstract:A seasonal decline in Clutch Size is typical of bird populations. This phenomenon may result from a conflict between the advantages of early breeding (greater offspring value) and the advantages of delay (greater accumulated condition and hence Clutch Size). We construct a dynamic model for adaptive seasonal decline in Clutch Size on the basis of these premises. The model requires a small number of well-supported assumptions; it is formulated and analyzed in both analytical and graphical forms. We outline some novel predictions and suggest tests of our conclusions. Initial comparisons of our predictions with results available from wild birds in the field are favorable. We briefly extend the model to consider the evolution of multiple Clutches within a season and the effects of between-season costs of reproduction. Although this work focuses on avian Clutch Size, the analysis provides a general framework for studies of conditiondependent transitions in life histories. Such transitions between stages (e.g.,...
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MATERNAL INHERITANCE OF CONDITION AND Clutch Size IN THE COLLARED FLYCATCHER.
Evolution; international journal of organic evolution, 1993Co-Authors: Dolph Schluter, Lars GustafssonAbstract:Maternal effects may strongly influence evolutionary response to natural selection but they have been little studied in the wild. We use a novel combination of experimental and statistical methods to estimate maternal effects on condition and Clutch Size in the collared flycatcher, where we define "condition" to be the nongenetic component of Clutch Size. We found evidence of two maternal effects. The first (m) was the negative effect of mother's Clutch Size on daughter's condition, when mother's condition was held constant. The second (M) was the positive effect of mother's condition on daughter's condition, when mother Clutch Size was held constant. These two effects oppose one another because mothers in good condition also lay many eggs. The maternal effects were large: Experimentally adding an egg to a mother's nest reduced Clutch Sizes of her daughters by 1/4 egg (i.e., m = -0.25). Measured degree of resemblance between mother and daughter Clutch Sizes yielded M = 0.43. The results weakly support the presence of heritable genetic variation in Clutch Size: additive genetic variance/total phenotypic variance = 0.33. This estimate was highly variable probably because, as we show, mother-daughter resemblance may depend hardly at all on the amount of genetic variance when maternal effects are present. Daughter-mother regression (a standard method for estimating heritability) is consequently a poor guide to the amount of genetic variance in Clutch Size. Our results emphaSize the value of combining field experiments with observations for studying inheritance.