bluuebunny/crossref_metadata_2025_split huggingface dataset:
Social competition, corticosterone and survival in female lizard morphs
Authors: Comendant T. , Sinervo B. , Svensson E. I. , Wingfield J. 
Published: December 2004

Abstract
We examined the selective consequences of variation in behaviour and endocrine physiology in two female throat-colour morphs of the lizard, Uta stansburiana in the wild. Female morphs differed in home-range distribution patterns and corticosterone levels in relation to the density and frequency of their female neighbours. Levels of plasma corticosterone of yellow-throated females increased with increased density of both morphs. In contrast, orange-throated females had reduced levels of corticosterone in response to increased density of orange females. Additionally, females with lower corticosterone survived poorly, suggesting that social interactions and high local densities of orange females may be potentially costly for orange females. These results are consistent with decreased fitness effects and suppression of immune function previously reported for orange female morphs surrounded by more orange neighbours. These correlations, in conjunction with previous work in this system, indicate that corticosterone is likely to be an important physiological mechanism regulating female fitness in nature.
Incongruent nuclear and mitochondrial phylogeographic patterns in the Timarcha goettingensis species complex (Coleoptera, Chrysomelidae)
Authors: Gómez-Zurita J. , Vogler A. P. 
Published: December 2004

Abstract
Phylogeographic analyses have mostly been based on single-gene genealogies but it is unclear how conclusions from such studies depend on the choice of gene markers. We conducted a nested geographical clade analysis [A.R. Templeton, E. Routman & C.A. Phillips (1995) Genetics140: 767–782] based on nuclear rDNA internal transcribed spacer region 2 (ITS2) sequences in the Timarcha goettingensis species complex (Coleoptera, Chrysomelidae), and compared the inferences with an updated version of previously published results using mitochondrial cytochrome oxidase II (COII) sequences. Inferences from ITS2 suggest that patterns of marker distribution are mostly explained by restricted gene flow with isolation by distance. In contrast, COII revealed a history of geographical structure resulting from episodic population contiguous-range expansions. Both markers also show different genealogical patterns, which are associated to the effects of genetic introgression in a putative hybrid zone between two major lineages in the complex. Altogether, these differences are attributed to distinct population and/or evolutionary dynamics of the markers, and offer a more accurate phylogeographic description for the T. goettingensis complex.
Sequential radiation of unrelated organisms: the gall fly Eurosta solidaginis and the tumbling flower beetle Mordellistena convicta
Authors: Abrahamson W. G. , Blair C. P. , Eubanks M. D. , Morehead S. A. 
Published: December 2004

Abstract
Host shifts and the formation of insect-host races are likely common processes in the speciation of herbivorous insects. The interactions of goldenrods Solidago (Compositae), the gall fly Eurosta solidaginis (Diptera: Tephritidae) and the beetle Mordellistena convicta (Coleoptera: Mordellidae) provide behavioural, ecological and genetic evidence of host races that may represent incipient species forming via sympatric speciation. We summarize evidence for Eurosta host races and show that M. convicta has radiated from goldenrod stems to Eurosta galls to form host-part races and, having exploited the galler's host shift, has begun to differentiate into host races within galls. Thus, host-race formation has occurred in two interacting, but unrelated organisms representing two trophic levels, resulting in ‘sequential radiation’ (escalation of biodiversity up the trophic system). Distributions of host races and their behavioural isolating mechanisms suggest sympatric differentiation. Such differentiation suggests host-race formation and subsequent speciation may be an important source of biodiversity.
Genetic architecture for normal and novel host-plant use in two local populations of the herbivorous ladybird beetle, Epilachna pustulosa
Authors: Ueno H. , Fujiyama N. , Yao I. , Sato Y. , Katakura H. 
Published: December 2004

Abstract
Trade-offs in host-plant use are thought to promote the evolution of host specificity. However, usually either positive or no genetic correlations have been found. Whereas factors enhancing variation in overall viability have been claimed to mask negative genetic correlations, alternative hypotheses emphasize the sequential changes in genetic correlation in the course of host-range evolution. In this study, the genetic architectures of performances on different hosts were compared in two populations of the herbivorous ladybird beetle, Epilachna pustulosa, using three host plants, one being normal for both, one novel for only one population, and the other novel for both populations. The genetic correlations between larval periods on normal hosts were significantly positive whereas those between normal and novel hosts were not different from zero. There was no evidence for reduced genetic variation on the normal host-plants. These results suggest that the host-range is not restricted by the antagonistic genetic associations among exploitation abilities on different plant species, but rather that selection of different host-plants may improve the coordination between genes responsible for the use of different plants.
Sexual conflict and cooperation under naturally occurring male enforced monogamy
Authors: Montrose V. T. , Harris W. E. , Moore P. J. 
Published: December 2004

Abstract
An evolutionary conflict often exists between the sexes in regard to female mating patterns. Females can benefit from polyandry, whereas males mating with polyandrous females lose reproductive opportunities because of sperm competition. Where this conflict occurs, the evolution of mechanisms whereby males can control female remating, often at a fitness cost to the female, are expected to evolve. The fitness cost to the female will be increased in systems where a few high status males monopolise mating opportunities and thus have limited sperm supplies. Here we show that in the cockroach Nauphoeta cinerea, a species where males enforce female monogamy in the first reproductive cycle, males that have become sperm depleted continue to be able to manipulate female remating behaviour. Although the manipulation severely decreases fecundity in females mated to sperm-depleted males, males benefit, increasing their relative fitness by preventing other males from reproducing. Our results suggest that there is selection on maintaining the mechanism of manipulation rather than maintaining sperm numbers. Taken with previous research on sexual conflict in N. cinerea, this study suggests that the causes and consequences of sexual conflict are complex and can change across the life history of an individual.
Molecular, morphological and behavioural data reveal the presence of a cryptic species in the widely studied Drosophila serrata species complex
Authors: Schiffer M. , Carew M. E. , Hoffmann A. A. 
Published: December 2004

Abstract
The Drosophila serrata species complex from Australia and New Guinea has been widely used in evolutionary studies of speciation and climatic adaptation. It is believed to consist of D. serrata, D. birchii and D. dominicana, although knowledge of the latter is limited. Here we present evidence for a previously undescribed cryptic member of the D. serrata species complex. This new cryptic species is widespread in far north Queensland, Australia and is likely to have been previously mistaken for D. serrata. It shows complete reproductive isolation when crossed with both D. serrata and D. birchii. The cryptic species can be easily distinguished from D. serrata and D. birchii using either microsatellite loci or visual techniques. Although it occurs sympatrically with both D. serrata and D. birchii, it differs from these species in development time, viability, wing size and wing morphology. Its discovery explains patterns of recently described mitochondrial DNA divergence within D. serrata, and may also help to clarify some ambiguities evident in early evolutionary literature on reproductive incompatibility within the D. serrata species complex.
The relationship between morphology, escape behaviour and microhabitat occupation in the lizard clade Liolaemus (Iguanidae: Tropidurinae*: Liolaemini)
Authors: Schulte J. A. , Losos J. B. , Cruz F. B. , Núñez H. 
Published: December 2004

Abstract
Phenotypic differences among species are known to have functional consequences that in turn allow species to use different habitats. However, the role of behaviour in this ecomorphological paradigm is not well defined. We investigated the relationship between morphology, ecology and escape behaviour among 25 species of the lizard clade Liolaemus in a phylogenetic framework. We demonstrate that the relationship between morphology and characteristics of habitat structure shows little or no association, consistent with a previous study on this group. However, a significant relationship was found between morphology and escape behaviour with the distance a lizard moved from a potential predator correlated with body width, axilla-groin length, and pelvis width. A significant relationship between escape behaviour and habitat structure occupation was found; lizards that occupied tree trunks and open ground ran longer distances from predators and were found greater distances from shelter. Behavioural strategies used by these lizards in open habitats appear to have made unnecessary the evolution of limb morphology that has occurred in other lizards from other clades that are found in open settings. Understanding differences in patterns of ecomorphological relationships among clades is an important component for studying adaptive diversification.
The origin of a ‘true’ worker caste in termites: mapping the real world on the phylogenetic tree
Authors: Grandcolas P. , D'Haese C. 
Published: December 2004

Abstract
The evolution of the ‘true’ worker caste in termites is not decisively inferred by coding and mapping both this character and the foraging behaviour on a phylogenetic tree. Answering to Thompson et al. (2000, 2003), and with reference to Grandcolas and D'Haese (2002), we show that this indecisive inference depends on the correct consideration paid to the outgroups. These last ones could be non subsocial cockroaches, or some wood-eating subsocial cockroaches often considered misleadingly as living ancestors, or even any hemimetabolous insects, all of them would be unambiguously lacking ‘true’ worker caste and pseudergate caste and not showing the ‘one-piece’ life type foraging behaviour. These statements derive from observing, coding and mapping the real world on the tree without making ad hoc assumptions. In that respect, because termites do not exist in isolation, apart from the tree of life, mapping the character of interest on the tree must be applied to the outgroups as well.
Copulation reduces male but not female longevity in Saltella sphondylli (Diptera: Sepsidae)
Authors: Martin O. Y. , Hosken D. J. 
Published: December 2004

Abstract
Mating more than once is extremely costly for females in many species, making the near ubiquity of polyandry difficult to understand. However, evidence of mating costs for males is much rarer. We investigated the effects of copulation on longevity of male and female flies (Saltella sphondylli). We also scrutinized potential fecundity and fertility benefits to females with differing mating history. Copulation per se was found to decrease the longevity of males but not that of females. However, when females were allowed to lay eggs, females that mated died earlier than virgin females, indicating costs of egg production and/or oviposition. Thus, although longevity costs of copulation are higher for males, reproduction is nevertheless costly for females. We also found no differences in fecundity or fertility relative to female mating history. Results suggest that polyandry may be driven by minor costs rather than by major benefits in this species.
Selection on floral characters in natural Spanish populations of Silene latifolia
Authors: Wright J. W. , Meagher T. R. 
Published: December 2004

Abstract
In insect-pollinated plants, floral characters are expected to play an important role in paternal and maternal reproductive success. Bateman's principle states that male reproductive success increases with more mating opportunities, while female reproductive success is limited by the amount of resources available to produce progeny, thus there should be greater selection on male floral characters than on female. In the case of the dioecious plant Silene latifolia, floral characters are likely to be influenced by its association within its native European range with moths of the genus Hadena, which serve as both pollinators and seed predators. The present study addresses relationships between male and female reproductive success, spatial location and floral characters (corolla, calyx and claw) over a 2-year period in two Spanish populations of S. latifolia in the presence of Hadena moths. A maximum likelihood paternity analysis using genetic variation at six allozyme markers showed heterogeneity in male reproductive success. There was much less variation in female reproductive success. When this analysis was extended to include interplant distance as a causal factor underlying variation in male success, we found that successful pollination tended to be limited to nearby females, in accordance with exponential decay of pollen dispersal with increasing distance. When the paternity analysis included floral characters as a causal factor underlying variation in male success, our data showed little evidence for directional selection, but there was stabilizing selection in one of the two years for calyx diameter. Selection on female characters varied widely between sites and years, in most of the site/year combinations there was little selection on female floral characters; however, in one site/year there was evidence for selection on all three floral characters. We conclude that pollinators visit flowers that are close together, and that while floral characters are important for the attraction of pollinators, larger flowers do not necessarily attract more pollinators at all sites and that variation among sites and years makes difficult any conclusions about the long-term importance of the predictions suggested by Bateman's principle.
Population structure and speciation in the genus Tursiops based on microsatellite and mitochondrial DNA analyses
Authors: Natoli Ada , Peddemors Victor M. , Rus Hoelzel A. 
Published: December 2004

Abstract
Bottlenose dolphins (Tursiops truncatus) have a world-wide distribution, and show morphotypic variation among regions. Distinctions between coastal and pelagic populations have been documented; however, regional patterns of differentiation had not been previously investigated in a wider geographic context. We analysed up to nine different populations from seven different areas of the world by mitochondrial DNA and microsatellite DNA markers, and found differentiation among all putative regional populations. Both mtDNA and microsatellite DNA data show significant differentiation, suggesting restricted gene flow for both males and females. Dolphins in coastal habitat showed less variability and were in most cases differentiated from a pelagic lineage, which could suggest local founder events in some cases. Two coastal populations recently classified as belonging to a new species, T. aduncus, were each highly differentiated from populations of the truncatus morphotype, and from each other, suggesting a possible third species represented by the South African aduncus type.
Plasticity in resource allocation based life history traits in the Pacific oyster, Crassostrea gigas. I. Spatial variation in food abundance
Authors: Ernande B. , Boudry P. , Clobert J. , Haure J. 
Published: December 2004

Abstract
We investigated the quantitative genetics of plasticity in resource allocation between survival, growth and reproductive effort in Crassostrea gigas when food abundance varies spatially. Resource allocation shifted from survival to growth and reproductive effort as food abundance increased. An optimality model suggests that this plastic shift may be adaptive. Reproductive effort plasticity and mean survival were highly heritable, whereas for growth, both mean and plasticity had low heritability. The genetic correlations between reproductive effort and both survival and growth were negative in poor treatments, suggesting trade-offs, but positive in rich ones. These sign reversals may reflect genetic variability in resource acquisition, which would only be expressed when food is abundant. Finally, we found positive genetic correlations between reproductive effort plasticity and both growth and survival means. The latter may reflect adaptation of C. gigas to differential sensitivity of fitness to survival, such that genetic variability in survival mean might support genetic variability in reproductive effort plasticity.
What maintains noncytoplasmic incompatibility inducing Wolbachia in their hosts: a case study from a natural Drosophila yakuba population
Authors: Charlat S. , Ballard J. W. O. , Merçot H. 
Published: December 2004

Abstract
Cytoplasmic incompatibility (CI) allows Wolbachia to invade hosts populations by specifically inducing sterility in crosses between infected males and uninfected females. In some species, non-CI inducing Wolbachia, that are thought to derive from CI-inducing ancestors, are common. In theory, the maintenance of such infections is not possible unless the bacterium is perfectly transmitted to offspring - and/or provides a fitness benefit to infected females. The present study aims to test this view by investigating a population of Drosophila yakuba from Gabon, West Africa. We did not find any evidence for CI using wild caught females. Infected females from the field transmitted the infection to 100% of their offspring. A positive effect on female fecundity was observed one generation after collecting, but this was not retrieved five generations later, using additional lines. Similarly, the presence of Wolbachia was found to affect mating behaviour, but the results of two experiments realized five generations apart were not consistent. Finally, Wolbachia was not found to affect sex ratio. Overall, our results would suggest that Wolbachia behaves like a neutral or nearly neutral trait in this species, and is maintained in the host by perfect maternal transmission.
Genetic variation, disequilibrium and natural selection on reproductive traits in Allium vineale
Authors: Ceplitis A. , Bengtsson B. O. 
Published: December 2004

Abstract
Bulbils and seeds collected from Allium vineale plants from natural populations were grown under uniform conditions. The bulbil-derived offspring represented the parental generation, whereas the seed-derived offspring represented the sexually produced offspring generation. Molecular markers were used to identify maternal genets. Variation in traits determining the allocation to sexual and asexual reproduction was partitioned among genets and ramet families in the parental and offspring generations. From observations of a release of genetic variation and slippage in the mean phenotype in the offspring generation, we inferred that there exists extensive genetic disequilibrium for reproductive traits in A. vineale populations, that most of the genetic variance is because of dominance effects, and that natural selection favours a reduced allocation to sexual reproduction. No genetic correlation between sexual and asexual allocation traits was found. We discuss the implications of these results with respect to the evolution of a mixed reproductive system in A. vineale.
Discrimination of cassava‐associatedBemisia tabaciin Africa from polyphagous populations, by PCR–RFLP of the internal transcribed spacer regions of ribosomal DNA
Authors: Abdullahi I. , Atiri G. I. , Thottappilly G. , Winter S. 
Published: December 2004

Abstract:Restriction fragment length polymorphism (RFLP) analysis of the ribosomal DNA internal transcribed spacer regions ofBemisia tabaciwas used to distinguish cassava‐associated populations from other host‐associated populations. Endonuclease restriction profile analysis indicated that cassava‐associated populations from Africa represent a distinct group, with a significant level of separation into subgroups that were not linked to geographical origin. Analysis of molecular variance (amova) revealed that a high proportion of the total genetic variation (47%) was attributable to among‐population differences within the host‐associated groups. Principal coordinate analysis supported the differentiation between the cassava and the non‐cassava group, a result which was in agreement with the cluster analysis of the restriction fragment profile. Internal transcribed spacer RFLP markers, especiallySmaI, identified in this study can be used to monitor the spread ofB. tabacibiotypes, especially of the more virulent biotype B that has so far not been reported in the cassava‐growing belt of Africa.
Evidences of non‐additive effects of multiple parasitoids on Diatraea saccharalis Fabr. (Lep., Crambidae) populations in sugarcane fields in Brazil
Authors: Rossi M. N. 
Published: December 2004

Abstract:Biological control is a relatively benign method of pest control. However, considerable debate exists over whether multiple natural enemies often interact to produce additive or non‐additive effects on their prey or host populations. Based on the large data set stored in the São João and Barra sugarcane mills (state of São Paulo, Brazil) regarding the programme of biological control of Diatraea saccharalis using the parasitoids Cotesia flavipes and tachinid flies, in the present study the author investigated whether the parasitoids released into sugarcane fields interfered significantly with the rate of parasitized D. saccharalis hosts. The author also observed whether there was an additive effect of releasing C. flavipes and tachinids on the rate of parasitized hosts, and looked for evidence of possible negative effects of the use of multiple parasitoid species in this biological control programme. Results showed that C. flavipes and the tachinids were concomitantly released in the Barra Mill, but not in the São Jão Mill. Furthermore, in the Barra Mill there was evidence that the parasitoids interacted because the percentage of parasitism did not increase after the release of either C. flavipes or tachinids. In the São João Mill, when both parasitoid species were released out of synchrony, both the percentage of parasitism by C. flavipes as well as that of the tachinids increased. When large numbers of tachinids were released in the Barra Mill, they caused a significant lower percentage of parasitism imposed by C. flavipes. The implications of the results as evidence of non‐additive effects of C. flavipes plus tachinids on D. saccharalis populations are discussed.