bluuebunny/crossref_metadata_2025_split huggingface dataset:
The importance of phylogenetic scale in tests of Bergmann's and Rapoport's rules: lessons from a clade of South American lizards
Authors: CRUZ F. B. , FITZGERALD L. A. , ESPINOZA R. E. , SCHULTE II J. A. 
Published: August 2005

AbstractWe tested for the occurrence of Bergmann's rule, the pattern of increasing body size with latitude, and Rapoport's rule, the positive relationship between geographical range size and latitude, in 34 lineages of Liolaemus lizards that occupy arid regions of the Andean foothills. We tested the climatic‐variability hypothesis (CVH) by examining the relationship between thermal tolerance breadth and distribution. Each of these analyses was performed varying the level of phylogenetic inclusiveness. Bergmann's rule and the CVH were supported, but Rapoport's rule was not. More variance in the data for Bergmann's rule and the CVH was explained using species belonging to the L. boulengeri series rather than all species, and inclusion of multiple outgroups tended to obscure these macroecological patterns. Evidence for Bergmann's rule and the predicted patterns from the CVH remained after application of phylogenetic comparative methods, indicating a greater role of ecological processes rather than phylogeny in shaping the current species distributions of these lizards.
Evolutionary dynamics and population biology of a polymorphic insect
Authors: SVENSSON E. I. , ABBOTT J. 
Published: August 2005

AbstractConspicuous heritable polymorphisms are useful to address the question if morph frequencies are stable or whether they fluctuate between generations. Ecological geneticists have studied colour polymorphisms in the past, but there are few long‐term studies of genetic dynamics across multiple generations. We studied morph‐frequency dynamics and female fecundity in the trimorphic blue‐tailed damselfly (Ischnura elegans). The morphs include a male‐coloured (androchrome) type of female, which is thought to be maintained by frequency‐dependent sexual conflict. Morph frequencies changed significantly between years across all populations. There was evidence for directional frequency change since androchrome females increased in 9 of 10 populations across a 4‐year period. There was heterogeneity between populations in their evolutionary trajectories, partly caused by population age: androchrome frequencies were initially high in young populations but gradually decreased and approached the level of old populations. We discuss the possible causes of morph‐frequency fluctuations, and the role of morph‐specific fecundity, dispersal and other forces influencing evolutionary dynamics in this system.
Does egg competition occur in marine broadcast‐spawners?
Authors: MARSHALL D. J. , EVANS J. P. 
Published: August 2005

AbstractWhen the availability of sperm limits female reproductive success, competition for sperm, may be an important broker of sexual selection. This is because sperm limitation can increase the variance in female reproductive success, resulting in strong selection on females to compete for limited fertilization opportunities. Sperm limitation is probably common in broadcast‐spawning marine invertebrates, making these excellent candidates for investigating scramble competition between broods of eggs and its consequences for female reproductive success. Here, we report our findings from a series of experiments that investigate egg competition in the sessile, broadcast‐spawning polychaete Galeolaria caespitosa. We initially tested whether the order in which eggs encounter sperm affects their fertilization success at two ecologically relevant current regimes. We used a split‐clutch—split‐ejaculate technique to compare the fertilization success of eggs from individual females that had either first access (competition‐free treatment) or second access (egg competition treatment) to a batch of sperm. We found that fertilization success depended on the order in which eggs accessed sperm; eggs that were assigned to the competition‐free treatment exhibited significantly higher fertilization rates than those assigned to the egg competition treatment at both current speeds. In subsequent experiments we found that prior exposure of sperm to eggs significantly reduced both the quantity and quality of sperm available to fertilize a second clutch of eggs, resulting in reductions in fertilization success at high and low sperm concentrations. These findings suggest that female traits that increase the likelihood of sperm‐egg interactions (e.g. egg size) will respond to selection imposed by egg competition.
Maternal genetic effects on adaptive divergence between anadromous and resident brook charr during early life history
Authors: PERRY G. M. L. , AUDET C. , BERNATCHEZ L. 
Published: August 2005

AbstractThe importance of directional selection relative to neutral evolution may be determined by comparing quantitative genetic variation in phenotype (QST) to variation at neutral molecular markers (FST). Quantitative divergence between salmonid life history types is often considerable, but ontogenetic changes in the significance of major sources of genetic variance during post‐hatch development suggest that selective differentiation varies by developmental stage. In this study, we tested the hypothesis that maternal genetic differentiation between anadromous and resident brook charr (Salvelinus fontinalisMitchill) populations for early quantitative traits (embryonic size/growth, survival, egg number and developmental time) would be greater than neutral genetic differentiation, but that the maternal genetic basis for differentiation would be higher for pre‐resorption traits than post‐resorption traits. Quantitative genetic divergence between anadromous (seawater migratory) and resident Laval River (Québec) brook charr based on maternal genetic variance was high (QST > 0.4) for embryonic length, yolk sac volume, embryonic growth rate and time to first response to feeding relative to neutral genetic differentiation [FST = 0.153 (0.071–0.214)], with anadromous females having positive genetic coefficients for all of the above characters. However,QSTwas essentially zero for all traits post‐resorption of the yolk sac. Our results indicate that the observed divergence between resident and anadromous brook charr has been driven by directional selection, and may therefore be adaptive. Moreover, they provide among the first evidence that the relative importance of selective differentiation may be highly context‐specific, and varies by genetic contributions to phenotype by parental sex at specific points in offspring ontogeny. This in turn suggests that interpretations ofQST‐FSTcomparisons may be improved by considering the structure of quantitative genetic architecture by age category and the sex of the parent used in estimation.
Reproductive ageing and sexual selection on male body size in a wild population of antler flies (Protopiophila litigata)
Authors: BONDURIANSKY R. , BRASSIL C. E. 
Published: August 2005

AbstractLittle is known about the importance of trade‐offs between ageing and other life history traits, or the effects of ageing on sexual selection, particularly in wild populations suffering high extrinsic mortality rates. Life history theory suggests that trade‐offs between reproduction and somatic maintenance may constrain individuals with higher initial reproductive rates to deteriorate more rapidly, resulting in reduced sexual selection strength. However, this trade‐off may be masked by increased condition dependence of reproductive effort in older individuals. We tested for this trade‐off in males in a wild population of antler flies (Protopiophila litigata). High mating rate was associated with reduced longevity, as a result of increased short‐term mortality risk or accelerated ageing in traits affecting viability. In contrast, large body size was associated with accelerated ageing in traits affecting mating success, resulting in reduced sexual selection for large body size. Thus, ageing can affect sexual selection and evolution in wild populations.
The evolution of fledging age in songbirds
Authors: ROFF D. A. , REMEŠ V. , MARTIN T. E. 
Published: August 2005

AbstractIn birds with altricial young an important stage in the life history is the age at fledging. In this paper we use an approach proven successful in the prediction of the optimal age at maturity in fish and reptiles to predict the optimal age of fledging in passerines. Integrating the effects of growth on future fecundity and survival leads to the prediction that the optimal age at fledging is given by a function that comprises survival to maturity, the exponent of the fecundity‐body size relationship and nestling growth. Growth is described by the logistic equation with parameters,A, Kandti. Assuming that the transitional mortality curve can be approximated by the nestling mortality,Mn, the optimal fledging age,tf, is given by a simple formula involving the three growth parameters, nestling mortality (Mn) and the exponent (d) of the fecundity‐body size relationship. Predictions of this equation underestimate the true values by 11–16%, which is expected as a consequence of the transitional mortality function approximation. A transitional mortality function in which mortality is approximately 0.3–0.4 of nesting mortality (i.e. mortality declines rapidly after fledging) produces predictions which, on average, equal the observed values. Data are presented showing that mortality does indeed decline rapidly upon fledging.
Changes in genetic architecture during relaxation in Drosophila melanogaster selected on divergent virgin life span
Authors: Vermeulen C. J. , Bijlsma R. 
Published: August 2005

Abstract
Artificial selection experiments often confer important information on the genetic correlations constraining the evolution of life history. After artificial selection has ceased however, selection pressures in the culture environment can change the correlation matrix again. Here, we reinvestigate direct and correlated responses in a set of lines of Drosophila melanogaster that were selected on virgin life span and for which selection has been relaxed for 10 years. The decrease in progeny production in long-lived lines, a strong indication of antagonistic pleiotropy, had disappeared during relaxation. This was associated with a higher cost of reproduction to long-lived flies in mated, but not in virgin life span. These data strongly suggest that genetic mechanisms of mated and virgin life span determination are partly independent. Furthermore, data on body weight, developmental time and viability indicated deleterious effects of longevity selection in either direction, giving rise to a nonlinear relationship with life span for these characters. In order to reclaim original patterns, we founded a new set of derived lines by resuming selection in mixed replicate lines of the original set. Although selection was successful, most patterns in correlated characters remained, showing that these new patterns are resistant to new episodes of selection.
The effect of female polyandry and sperm precedence on the evolution of sexual difference in dispersal timing
Authors: HIROTA T. 
Published: August 2005

AbstractPredispersal copulation and unpredictable environment facilitate the evolution of female‐biased dispersal in species, where females are functionally monandrous. Females should migrate and reproduce over different habitats to spread their risks due to environmental fluctuation. On the other hand, males do not have to disperse because their risks are spread by their mating partners who produce their offspring in different habitats. However, when females are functionally polyandrous, it is expected that they will not contribute to spreading the male's risk extensively. Therefore, by simulation with the individual based model, the present study evaluated how female polyandry influences the sexual difference in dispersal timing. This model revealed that when females are polyandrous, the timing of female remating and sperm priority patterns have an important influence on the evolution of sex‐biased dispersal. Particularly when female remating is not synchronized with dispersal or when last‐male sperm precedence does not exist, female‐biased dispersal is evolved.
Geographical patterns of adaptation within a species’ range: interactions between drift and gene flow
Authors: Alleaume-benharira M. , Pen I. R. , Ronce O. 
Published: August 2005

Abstract
We use individual-based stochastic simulations and analytical deterministic predictions to investigate the interaction between drift, natural selection and gene flow on the patterns of local adaptation across a fragmented species’ range under clinally varying selection. Migration between populations follows a stepping-stone pattern and density decreases from the centre to the periphery of the range. Increased migration worsens gene swamping in small marginal populations but mitigates the effect of drift by replenishing genetic variance and helping purge deleterious mutations. Contrary to the deterministic prediction that increased connectivity within the range always inhibits local adaptation, simulations show that low intermediate migration rates improve fitness in marginal populations and attenuate fitness heterogeneity across the range. Such migration rates are optimal in that they maximize the total mean fitness at the scale of the range. Optimal migration rates increase with shallower environmental gradients, smaller marginal populations and higher mutation rates affecting fitness.
Yolk androgens in the barn swallow (Hirundo rustica): a test of some adaptive hypotheses
Authors: Gil D. , Ninni P. , Lacroix A. , De Lope F. , Tirard C. , Marzal A. , Pape MøLler A. 
Published: August 2005

Abstract
Maternal effects such as androgen in avian eggs can mediate evolutionary responses to selection, allowing manipulation of offspring phenotype and promoting trans-generational adaptive effects. We tested the predictions of two adaptive hypotheses that have been proposed to explain female variation in yolk androgen allocation in birds, using the barn swallow Hirundo rustica as a model. We found no support for the first hypothesis proposing that yolk androgen varies as a function of breeding density in order to prepare offspring for different breeding densities. However, we found experimental support for the hypothesis that female yolk androgen allocation depends on mate attractiveness and that it constitutes an example of differential allocation. Females increased the concentration of androgens in their eggs when mated to males with experimentally elongated tails. Female phenotypic quality as measured by arrival date and clutch size was positively related to egg androgen concentration, consistent with the hypothesis that this is a costly investment, constrained by female condition. We found correlative evidence of a direct relationship between egg androgen concentration and performance of offspring as measured by mass increase.
Analysis of microsatellite variation in Pinus radiata reveals effects of genetic drift but no recent bottlenecks
Authors: Karhu A. , Vogl C. , Moran G. F. , Bell J. C. , Savolainen O. 
Published: August 2005

Abstract
Most conifer species occur in large continuous populations, but radiata pine, Pinus radiata, occurs only in five disjunctive natural populations in California and Mexico. The Mexican island populations were presumably colonized from the mainland millions of years ago. According to Axelrod (1981), the mainland populations are relicts of an earlier much wider distribution, reduced some 8000 years ago, whereas according to Millar (1997, 2000), the patchy metapopulation-like structure is typical of the long-term population demography of the species. We used 19 highly polymorphic microsatellite loci to describe population structure and to search for signs of the dynamics of population demography over space and time. Frequencies of null alleles at microsatellite loci were estimated using an approach based on the probability of identity by descent. Microsatellite genetic diversities were high in all populations [expected heterozygosity (He) = 0.68–0.77], but the island populations had significantly lower estimates. Variation between loci in genetic differentiation (FST) was high, but no locus deviated statistically significantly from the rest at an experiment wide level of 0.05. Thus, all loci were included in subsequent analysis. The average differentiation was measured as FST = 0.14 (SD 0.012), comparable with earlier allozyme results. The island populations were more diverged from the other populations and from an inferred common ancestral gene pool than the mainland ones. All populations showed a deficiency of expected heterozygosity given the number of alleles, the mainland populations more so than the island ones. The results thus do not support a recent important contraction in the mainland range of radiata pine.
Cophylogenetic relationships between penguins and their chewing lice
Authors: Banks J. C. , Palma R. L. , Paterson A. M. 
Published: August 2005

Abstract
It is generally thought that the evolution of obligate parasites should be linked intimately to the evolution of their hosts and that speciation by the hosts should cause speciation of their parasites. The penguins and their chewing lice present a rare opportunity to examine codivergence between a complete host order and its parasitic lice. We estimated a phylogeny for all 15 species of lice parasitising all 17 species of penguins from the third domain of the mitochondrial 12S ribosomal rRNA gene, a portion of the mitochondrial cytochrome oxidase subunit 1 gene and 55 morphological characters. We found no evidence of extensive cospeciation between penguins and their chewing lice using TreeMap 2.02β. Despite the paucity of cospeciation, there is support for significant congruence between the louse and penguin phylogenies due to possible failure to speciate events (parasites not speciating in response to their hosts speciating).
Measuring natural and sexual selection on breeding values of male display traits in Drosophila serrata
Authors: Skroblin A. , Blows M.W. 
Published: August 2005

Abstract
Fundamental to many theories of sexual selection is the expectation that sexual traits, which males use in an attempt to increase mating success, confer costs as well as benefits to individual males. Although evolution of exaggerated male traits is predicted to be halted, by costs applied by natural selection, there is a lack of empirical work devoted to quantitatively establishing whether natural selection opposes sexual selection generated by the preferences of females. In this study, we quantified natural and sexual selection gradients on breeding values for cuticular hydrocarbon (CHC) components of male contact pheromones in Drosophila serrata. As male sexual traits may often be environmentally condition dependent, breeding values were used in the selection analysis to remove the possibility of environmental correlations between the measured trait and fitness biasing estimates of selection. The direction of natural selection was found to oppose sexual selection on a subset of CHCs examined. Opposing natural and sexual selection suggests that further evolution of the male pheromone may in part be limited by costs associated with attractive male CHC blends.
NEONATAL AND MATERNAL SERUM IRON LEVELS AT BIRTH
Authors: Kessel I. , Sills D. J. 
Published: August 2005

SummaryThe serum iron levels in mothers and their newborn full‐term infants at the time of birth has been measured. There is no correlation between the maternal and neonatal levels, and the high cord blood serum levels bear no relation to sex or birthweight.
LATENT DIABETES IN PREGNANCY
Authors: Drury M. I. , Timoney F. J. 
Published: August 2005

SummaryGlycosuria, a family history of diabetes mellitus, a history of previous unexplained fetal loss or of large babies may indicate possible latent diabetes in pregnancy. The value of the oral glucose tolerance test in detecting latent diabetes in an antenatal clinic over a five‐year period is reviewed and 220 women with latent diabetes were observed in 293 pregnancies. The fetal loss in 244 viable pregnancies in which latent diabetes was recognized prior to delivery was 2.9 per cent.The cortisone modified glucose tolerance test employed after the puerperium in 108 of the women was of less diagnostic value as a test for latent diabetes than pregnancy itself.
GASTRIC EMPTYING TIME IN LATE PREGNANCY AND LABOUR
Authors: Davison Joseph S. , Davison Mary C. , Hay David M. 
Published: August 2005

SummaryGastric emptying was measured in non‐pregnant, pregnant and labouring women.The results suggest an explanation for previously conflicting studies and support the suggestion that slowing of gastric emptying contributes to heartburn in pregnancy. However, there was no clear evidence that in pregnant women generally gastric emptying is impaired.Gastric emptying times during labour were shown to be prolonged and the pattern of emptying altered.
AN INVESTIGATION OF THE CELLULAR SOURCE OF RENIN IN HUMAN CHORION
Authors: Symonds E. M. , Skinner S. L. , Stanley M. A. , Kirkland J. A. , Ellis R. C. 
Published: August 2005

SummaryAn investigation has been made into the cellular source of renin in human chorion. Using cytogenetic techniques the cells producing renin in tissue cultures of chorion have been identified as fetal and not maternal in origin.Histochemical studies using the Bowie stain have shown the presence of cells containing Bowie‐positive granules in the cytoplasm in the spongy layer of amnion and the reticular layer of chorion. These cells do not occur in the trophoblastic layer and morphologically have been shown to resemble the Hofbauer cell.Chorion cells producing renin during in vitro culture do not, however, display Bowie‐positive cytoplasmic granules.
A CONTINUOUS RECORD OF FETAL HEART RATE OBTAINED BY SERIAL COUNTS
Authors: Steer P. J. , Beard R. W. 
Published: August 2005

SummaryA simple method for obtaining a continuous record of the fetal heart rate by serial counting in relation to uterine contractions, recorded by abdominal palpation, is described.By comparing serial counts with the record obtained at the same time of a continuous heart rate monitor it has been shown that the optimal counting period is 10 seconds. Comparison of records obtained by several observers shows no significant influence of experience on the accuracy of counting or of palpating uterine contractions.
THE INTERPRETATION OF URINARY OESTROGEN AND PREGNANEDIOL EXCRETION IN PREGNANT WOMEN RECEIVING CORTICOSTEROIDS
Authors: Oakey R. E. 
Published: August 2005

SummaryThe urinary excretion of oestrogens and pregnanediol of 17 pregnant women who were receiving corticosteroids was measured. In all 10 patients who received less than 75 mg. cortisol (or its equivalent) daily and who gave birth to infants of satisfactory weight and without fetal abnormality, oestrogen excretion was within the normal range. The 4 patients who received less than 75 mg. cortisol daily but who showed subnormal oestrogen excretion gave birth to infants with retarded fetal growth or, in 1 instance, with hypoplastic adrenal glands. All 3 patients who received more than 75 mg. cortisol daily showed subnormal oestrogen excretion. Urinary pregnanediol excretion was within the normal range in 5 out of the 7 pregnancies in which oestrogen excretion was subnormal.It is concluded that subnormal oestrogen excretion in pregnant women who are receiving less than 75 mg. cortisol (or equivalent) daily is indicative of a failure of the fetus to thrive.
THE VASCULAR PATTERNS IN MYOMATOUS UTERI
Authors: Farrer‐Brown Geoffrey , Beilby J. O. W. , Tarbit M. H. 
Published: August 2005

SummaryThe arterial and venous patterns in myomatous uteri have been studied by injection, microradiographic and histological techniques. The changes of the myometrial and endometrial veins produced by myomata are illustrated and their importance as a cause of uterine bleeding is discussed.