bluuebunny/crossref_metadata_2025 huggingface dataset:
‘What do you think?’: a qualitative approach to evaluating individual planning services
Authors: Carnaby S.
Published: December 2004

An established individual planning service was evaluated using a service‐user‐centred approach, which looked at the extent to which people are involved in the process and their understanding of its nature and function. Responses recorded during interviews with service users, their key workers and some family members are complemented with data collected from participant observation of individual planning meetings. The findings suggest that the majority of service users able to speak for themselves who were interviewed have a good understanding of the planning process and find it a positive experience; this is supported by participant observation data. Those speaking on behalf of people unable to speak for themselves are unclear as to how much understanding the group has of the process. Observation data suggest that people needing others to speak on their behalf are excluded from discussion during meetings more often than they are included. Recommendations are made for developing the service and providing additional support for keyworkers, building upon the considerable progress made during the service's inception.
Clinical considerations in digitate dermatosis
Authors: Mueller Kurt K. , Yeager Josef K.
Published: December 2004

A 53‐year‐old man presented for evaluation of erythematous plaques over the trunk which had been present for several months. The lesions were asymptomatic and were not changing in appearance or number. The patient was in otherwise good health and had no history of dermatologic problems.

Significant physical findings were well‐defined, elongated, erythematous plaques lying in parallel along both sides of the lower trunk (Figs la and 1b). There was no lymphadenopathy or visceral enlargement. A skin biopsy showed a lymphocytic perivascular infiltrate with epidermal spongiosis, acanthosis, and parakeratosis. On the basis of the clinical and histopathologic findings, and diagnosis of digitate dermatosis was established and the patient has done well without treatment.
Lymphocutaneous infection due to Scedosporium apiospermum
Authors: Kusuhara Masahiro , Hachisuka Hiroshi
Published: December 2004

A 67‐year‐old Japanese man had been treated occasionally for asthma by oral administration of prednisolone at a dose between 5 and 15 mg/day for 18 years. In December 1993, the patient had a severe asthma attack, during which he developed a pneumothorax, complicated by pneumonia. He was hospitalized immediately, and antibiotics and hydrocortisone were administered intravenously. The treatment was, however, ineffective and his condition deteriorated. In February 1994, he was treated with pulse therapy of 1 g/day of sodium hydrocortisone for 3 days. During the pulse therapy, erythema and red papules were noticed on his right dorsum manus. The erythema progressed with purpura, induration, and local fever. The papules became necrotic, giving rise to small ulcers with effusions (Fig. 1). The patient also developed a subcutaneous nodule on the proximal region of his forearm.

Laboratory investigations revealed anemia (hemoglobin (Hb), 9.6 g/dL), leucocytosis (leukocyte count, 11,800/mm3), slight liver dysfunction (GOT 32KU, GPT 71KU, LDH 759UU), and hypoaluminemia (albumin (Alb), 2.7 mg/dL). A biopsy of the indurated erythema of the dorsum manus was performed.

The histopathology of the biopsied tissue showed diffuse infiltration with inflammatory cells, edema, and necrosis in the mid‐dermis and fat. The infiltrate consisted of lymphocytes, neutrophils, histiocytes, and occasional giant cells. Many mycelial form fungal elements were observed (Fig. 2a), and aggregates of hyphae were also found in the lower dermis (Fig. 2b). Similar findings were noted for the biopsied specimen of the forearm subcutaneous nodule.

Biopsied material was inoculated on Sabouraud's dextrose agar, and floccose and smoky‐gray colonies grew rapidly at room temperature for 7 days (Fig. 3a). Microscopic findings showed that the hyphae were broad, branching, and brown in color. Round or oval conidia were produced singly on short conidiophores from the sides of the hyphae, or terminally on long conidiophores (Fig. 3b). Scanning electron microscopy showed an oval conidium produced from the terminus of the conidiophore with annellation. Although we observed the cultured mycelium for several months, cleistothecia were not produced. From these findings, we identified the organism as Scedosporium apiospermum, the asexual stage of Pseudallescheria boydii. The organism was not isolated from sputum or blood cultures.

The patient was given fluconazole intravenously at 400 mg/day. Although the treatment was stopped after 2 weeks, because of increasing serum transaminase, the erythema and subcutaneous nodule almost completely disappeared after 5 weeks.
Neurocutaneous melanosis and Dandy‐Walker syndrome in an infant
Authors: Green Lawrence J. , Nanda Vandana S. , Roth Gerald M. , Barr Ronald J.
Published: December 2004

An 18‐week‐old boy was referred by the pediatric service for evaluation of a large congenital nevus. The baby was a term infant who was noted to have extensive pigmented skin lesions at birth that extended from the scalp to the feet. Apgar scores and physical examination (including neuromuscular examination) were within normal limits. Electroencephalographic tracings were normal and unenhanced cranial computerized tomography (CT) was reported as showing a subarachnoid cyst with atrophic changes, involving predominantly the inferior aspect of the cerebellar hemispheres bilaterally. Hydrocephalus or signs thereof were not present. Lumbar spine films were normal. The patient was next evaluated at age 3 months, where he was reported to roll over, reach for objects, and smile.

At age 17 weeks, the baby had dermabrasion of an abdominal portion of his congenital nevus, followed by autologous epidermal cell autograft. The baby was subsequently hospitalized at the University of California Irvine Medical Center for complications from this procedure. Upon initial dermatologic evaluation, the baby was noted to have uniformly brown pigmented bathing‐trunk verrucous lesions covering his buttocks, scrotum, two‐thirds of his trunk, and proximal portions of his extremities. Multiple similar but smaller lesions were noted on the face, scalp, and distal extremities (Fig. 1). Tense anterior fontanelles, frontal bossing, Babinski reflexes bilaterally, and possible “setting‐sun” sign (downward gaze of the eyes secondary to pressure from the midbrain) were apparent. Although the length (size) percentile for the baby was normal, the plot of head circumference was noted to deviate above the normal range by age 3 months.

Magnetic resonance imaging (MRI) of the brain was performed. The midline sagittal T1 weighted image (Fig. 2a) demonstrated an enlarged posterior fossa with vermin hypoplasia and hydrocephalus. An axial image through the dilated sylvian aqueduct revealed a hyperintense focus, characteristic of melanocytes, adjacent to the dilated left temporal horn (Fig. 2b). More superiorly, enhancing leptomeningeal deposits were identified (not shown). Cerebrospinal fluid was obtained after subsequent placement of a right ventricular‐peritoneal shunt. The fluid was bloody, but sterile, and without malignant cells. Staining for melanin of the few nucleated cells in this limited cerebrospinal fluid sample was negative. Several excisional biopsies of a nevus from locations on the feet, wrist, back, and buttock showed the picture of either congenital melanocytic nevus or congenital melanocytic nevus with atypical melanocytic hyperplasia; however, no significant atypia was identified in the specimens containing foci of atypical melanocytic hyperplasia.
The function of anal papillae in salt adaptation of Drosophila melanogaster larvae
Authors: Te Velde J. H. , Molthoff C. F. M. , Scharloo W.
Published: December 2004

The anal papillae of Drosophila melanogaster larvae showed strong developmental plasticity in media with different osmotic pressure. The size of the papillae decreased with increasing salt content of the medium, which supports the hypothesis of its absorptive function. We showed that CI‐transport at the site of the anal papillae decreased with increasing salt concentration, which also supports the hypothesis, that the function of anal papillae in osmoregulation is absorption at low salt content and not excretion at high salt content.

The inactive area between the anal papillae increased with increased salt concentration, and thus contributed to the decreasing size of the anal papillae. Remnants of this area in pupae were mistakenly measured as anal papillae in a study on salt adaptation by Waddington (1959).
A critique of methods for measuring life history trade‐offs
Authors: Pease C. M. , Bull J. J.
Published: December 2004

Constraints have important effects on the evolution of life history strategies, but several difficulties have been encountered in determining constraints empirically. Here we investigate methods for measuring a specific type of constraint known as a trade‐off. A trade‐off between two traits implies a perfect negative correlation between the traits. Trade‐offs may involve more than two traits, however, and pairs of traits involved in such a higher‐dimensional trade‐off may be positively correlated. If some of the traits involved in a trade‐off are omitted from the experimental design, the trade‐off may not even be detectable. Direct measures of trade‐offs are thus complicated, and indirect means of identifying trade‐offs may often provide the only feasible measures.
Reaction norms for developmental time and weight at eclosion in Drosophila mercatorum
Authors: Gebhardt Martin D. , Stearns Stephen C.
Published: December 2004

We determined reaction norms for developmental time and weight at eclosion for 2 isozygous and 11 genetically mixed strains of Drosophila mercatorum in four culture media differing in yeast concentration. With decreasing yeast concentration, development was delayed, the weight of emerging flies decreased, and the phenotypic variance of both variables increased. Differences among stocks and significant stock × yeast interactions indicated genetic variance for both variables within environment and different phenotypic responses of stocks across environments. The phenotypic correlation between developmental time and weight was negative at low yeast concentrations and disappeared gradually with increasing yeast. The comparison of completely homozygous with genetically heterogenous stocks showed that most of the increase of variability with deteriorating environment was due to the changing expression of genetic variance. The genetic correlation between developmental time and weight turned from negative in poor to positive in rich medium, while the environmental covariance was negative in all media. Plotting the reaction norms in the developmental time‐weight plane rather than separately for each trait reveals most of these results at a glance. It also suggests that much of the genetic variance might be additive, because an effect of the half‐sib family structure inherent in the design is clearly visible in the plot. We interpret the pattern of changing variances and covariances, pointing out that the special growth physiology of Drosophila and the way environmental factors affect it must be taken into account. We briefly discuss the implications of changing genetic correlations among traits for the evolution of phenotypic plasticity in general.
Heterochrony: Developmental mechanisms and evolutionary results
Authors: Raff Rudolf A. , Wray Gregory A.
Published: December 2004

The concept of heterochrony, that the relative timing of ontogenetic events can shift during evolution, has been a major paradigm for understanding the role of developmental processes in evolution. In this paper we consider heterochrony from the perspective of developmental biology. Our objective is to redefine heterochrony more broadly so that the concept becomes readily applicable to the evolution of the full range of ontogenetic processes, from embryogenesis through the adult. Throughout, we stress the importance of considering heterochrony from a hierarchical perspective. Thus, we recognize that a heterochronic change at one level of organization may be the result of non‐heterochronic events at an underlying level. As such, heterochrony must be studied using a combination of genetic, molecular, cellular, and morphological approaches.
Establishment of a tetraploid cytotype in a diploid population: Effect of relative fitness of the cytotypes
Authors: Felber François
Published: December 2004

The conditions for the establishment of a tetraploid in a diploid population were investigated by means of a deterministic model, on the assumption that the diploid cytotype produces some 2n gametes.

If the fertility and viability of both cytotypes were the same and the initial population was diploid, then a mixed population would occur if the production of 2n gametes was below 17.16%. The tetraploid excluded the diploid above this limit. By modifying the fertility and the viability of the polyploid this threshold varied, dropping to 10% when one of the two parameters was twice that of the diploid, and falling to as low as 6% if both fertility and viability were double that of the diploid.

The conditions for the establishment of a polyploid are therefore quite restrictive under the assumptions of this model. In nature, such processes would probably allow the spread of the polyploid only if the immigration of polyploids considerably enhanced the frequency of tetraploids, or if genetical or environmental changes, or chance processes in small populations caused a substantial increase in the frequency of 2n gametes produced by the diploid.
Phylogeographic histories of representative herpetofauna of the southwestern U.S.: mitochondrial DNA variation in the desert iguana (Dipsosaurus dorsalis) and the chuckwalla (Sauromalus obesus)
Authors: Lamb Trip , Jones Thomas R. , Avise John C.
Published: December 2004

To determine whether genetic variation in representative reptiles of the southwestern U.S. may have been similarly molded by the geologic history of the lower Colorado River, we examined restriction site polymorphisms in the mitochondrial DNA (mtDNA) of desert iguanas (Dipsosaurus dorsalis) and chuckwallas (Sauromalus obesus). Observed phylogeographic structure in these lizards was compared to that reported for the desert tortoise (Xerobates agassizi), whose mtDNA phylogeny demonstrates a striking genetic break at the Colorado River.

Both the desert iguana and chuckwalla exhibit extensive mtDNA polymorphism, with respective genotypic diversities G = 0.963 and 0.983, close to the maximum possible value of 1.0. Individual mtDNA clones, as well as clonal assemblages defined by specific levels of genetic divergence, showed pronounced geographic localization. Nonetheless, for each species the distributions of certain clones and most major clonal groupings encompass both sides of the Colorado River valley, and hence are clearly incongruent with the phylogeographic pattern of the desert tortoise. Overall, available molecular evidence provides no indication that the intraspecific phylogenies of the southwestern U.S. herpetofauna have been concordantly shaped by a singular vicariant factor of overriding significance.
Disturbance, competition and the maintenance of clonal diversity in Daphnia pulex
Authors: Weider Lawrence J.
Published: December 2004

Laboratory microcosm experiments tested the intermediate disturbance hypothesis, which states that the highest level of diversity (e.g. species diversity) will be maintained at intermediate scales of disturbance. The effects of disturbance on the maintenance of clonal diversity and on competitive interactions among clones of the obligately parthenogenetic freshwater cladoceran, Daphnia pulex were examined. No significant effect of disturbance size (i.e. dilution volume) on clonal diversity was noted. However, frequency of disturbance had a pronounced effect on clonal diversity, with the highest clonal diversity maintained at low to intermediate disturbance frequencies. Competitive hierarchies among clones were often invariant within a given experiment. Generally, one or two clones dominated, with several less abundant clones persisting throughout an experiment. Results suggest that low to intermediate disturbances could be important in the maintenance of genetic variation in natural populations (i.e. through pre‐emption of competitive exclusion between genotypes). This could have a direct bearing on the maintenance of both intra‐ and interspecific diversity.
The genetics of phenotypic plasticity. VI. Theoretical predictions for directional selection
Authors: Gavrilets Sergey , Scheiner Samuel M.
Published: December 2004

We explore the effects of linear and quadratic reaction norms on heritability and directional selection. Genetic variation for reaction norm parameters can alter the heritability of traits; the magnitude of the heritability depends upon both the environment and the correlation among the parameters. Genetic variation for reaction norm parameters can alter the response to directional selection. Selection on a trait in one environment can shift both the mean of the trait measured across environments and the plasticity of the trait; the signs and magnitudes of these responses depend on the correlations among the parameters of the reaction norm. Our model is consistent with the results of ten experiments for selection on a trait in a single environment. In all experiments, selection towards the overall mean of the population always resulted in a relatively lower plasticity than selection away from the overall mean. Our model was able to predict the results of two experiments for selection on a trait index calculated over more than one environment. Predictions were good for the direct response to selection but poorer for the correlated response to selection. Our results indicate the need for more data on the effects of environment on genetic parameters, especially correlations among reaction norm parameters.
Parental care as a game
Authors: Yamamura N. , Tsuji N.
Published: December 2004

A new game model of parental care is presented where fitnesses of males and females depend on frequencies of care and no‐care strategies in the population, as well as strategies of individuals and those of their mates. Evolutionarily stable states (ESS) of biparental‐care (BC), female‐care (FC), male‐care (MC), and no‐care (NC) are represented as regions in a 3‐dimensional parameter space, comprising the ratio of the number of offspring raised by FC or MC to that by BC, the ratio of that by NC to that by FC or MC, and the sex ratio. ESSs are not necessarily uniquely determined: ESS regions of FC and MC overlap in parts, as well as those of BC and NC. In a region where none of the four states is ever an ESS, a polymorphism (a mixed state of care and no‐care strategies in one or both sexes) is stable. Although an asymmetry between prezygotic investment times of males and females results in the difference in sizes of the ESS regions of FC and MC, it is not responsible for determining whether FC or MC evolves from other modes of parental care as a result of slowly changing parameters. The key factor is the sex ratio of adults in the population. By a slightly modified model, it is also shown that paternity uncertainty at fertilization of eggs is highly important for evolution of FC.
Do peacock's trains advertise age?
Authors: Petrie Marion
Published: December 2004

Manning (1987 and 1989) found a positive correlation between several measured aspects of the male's upper tail coverts and male age in a sample of males measured at several different sites. Here we test whether or not the trains of individuals from the same population increase between years. There is no evidence from the data presented that variation in the degree of train elaboration amongst male peacocks is age‐dependent beyond 4 years or that peahens always prefer to mate with older males; one young male in his first year of displaying achieved high mating success and was preferred by several females over other older males present. It therefore appears unlikely that the peacock's train acts as an age‐indicator.
Transfer of a parasitic sex factor to the nuclear genome of the host: A hypothesis on the evolution of sex‐determining mechanisms in the terrestrial Isopod Armadillidium vulgare Latr.
Authors: Juchault P. , Mocquard J. P.
Published: December 2004

In A. vulgare sex is usually determined either by a cytoplasmic feminizing factor (F symbiotic bacteria) or by another feminizing factor (f) which behaves like a mobile element of DNA and which seems to correspond to a fragment of bacterial DNA. By inhibiting the expression of male genes carried by the Z heterochromosome, these feminizing factors induce differentiation of neo‐females [ZZ(+F) or ZZ(+f)]. Such a mechanism leads to the production of progenies whose sex ratio is highly female biased. In some populations in which F and/or f factors are present, genetic females (WZ) have disappeared and all individuals (males and females) are genetic males. However in other populations, cohabitation of ZZ(+f) neo‐females and females in all points similar to genetic females is observed. Such a situation may be unstable and is not likely to be explainable only by migrations of individuals from distinct populations.

Owing to certain types of crosses, in particular those which involve an artificial neo‐male ( = female reversed into a functional male by an implant of androgenic gland) we show here that the f factor can be transmitted as a Mendelian gene. In these progenies ZfZ females may appear: like WZ females, they breed broods whose sex ratio is unbiased. The hypothesis that the “F bacteria—A. vulgare” symbiosis may have led, after a complex co‐evolutive process (F bacteria → f mobile element → insertion of f on Z heterochromosome), to the creation (from a male genotype) of a female genotype, is put forward. The consequences of such a phenomenon on the composition and the evolution of A. vulgare populations are examined.
Sex allocation variation in Daphnia pulex
Authors: Innes David J. , Dunbrack Robert L.
Published: December 2004

Daphnia
(Crustacea: Cladocera) reproduce by cyclical parthenogenesis in which the sex of offspring is environmentally determined. Although numerous studies have demonstrated that factors such as crowding and short‐day photoperiod stimulate male production, there is limited information on variation in allocation to male and female offspring for any species of
Daphnia
. The present study assessed the presence or absence of male production in 96 isofemale lines (clones) from each of eight populations of
Daphnia pulex
. An average of 37% (range 18–51%) of clones failed to produce males under crowded conditions in the laboratory. A subset of 14 of these non‐male‐producing clones also failed to produce males under short‐day photoperiod (8L:16D). Three male‐producing clones were within‐clone mated as well as crossed to three non‐male‐producing clones to study the inheritance of the failure to produce males. The average frequency of non‐male‐producing F
1
progeny was significantly higher (58%,
N
= 486) among the outcrossed progeny than the inbred progeny (5%,
N
= 86). In addition, when sixteen of the male‐producing outcrossed progeny were within‐clone mated, only 7% (
N
= 106) of the resulting F
2
progeny failed to produce males. These results are consistent with a genetic basis for the absence of male production. Average survival of the progeny from the nine outcrossed matings was more than twice (67%) that of the inbred progeny from the three within‐clone matings (30%), suggesting that within‐clone mating would result in significant inbreeding depression. We present a model that suggests that even low levels of inbreeding could allow non‐male‐producing females to be maintained in a population. The co‐occurrence of non‐male‐producing females and females that produce both males and females in
Daphnia pulex bears a similarity to the gynodioecious breeding system found in some plant species.
Drosophila C virus and Drosophila hosts: a good association in various environments
Authors: Gomariz‐Zilber Eliane , Thomas‐Orillard Michèle
Published: December 2004

To discover whether the beneficial effects observed when Drosophila C virus (DCVC) infects Drosophila larvae should be considered as a specific case or, as a general rule, the DCVC‐Drosophila association was studied in different environments (3 host‐populations, 2 temperatures, 2 viral dose). We measured pre‐adult mortality, developmental time and number of ovarioles per fly. In all experiments, and, in all contaminated populations, DCVC could be considered, either a parasite since it increased pre‐adult mortality, or a symbiont since it decreased developmental time and increased mean number of ovarioles. The viral dose necessary for the appearance of beneficial effects varied with population, temperature and life‐cycle parameters. A sufficient number of viral particles appears necessary at a specific point in the host life‐cycle for a beneficial DCVC effect on the host. DCVC does not affect the variance of any of these parameters. The observed changes in DCVC‐contaminated populations were thus not a response to the selection pressure of DCVC. Two arguments support the association as an example of the “cohabitation‐without‐struggle model” and will be discussed.
Evolution of clutch size in insects. II. A test of static optimality models using the beetle Callosobruchus maculatus (Coleoptera: Bruchidae)
Authors: Wilson Kenneth
Published: December 2004

Wilson and Lessells (1993) analysed the effect of constraint assumptions on the predictions of static optimality models for insect clutch size. They concluded that the models could be reliably distinguished between (and hence the main constraints identified) only after precise quantitative predictions had been examined. The present paper describes a series of laboratory experiments, using the bruchid beetle Callosobruchus maculatus, that allow these quantitative predictions to be made and tested. Experiments in which female encounter rate with hosts was altered gave qualitative support for 3 out of 6 basic (single oviposition) models, but the quantitative fit of them all was poor. However, when the (a priori) condition was included in these models that several other females would oviposit on the same hosts (the multiple oviposition models), the time limiting multiple oviposition model alone produced quantitative predictions that were supported by observations. In other words, the results suggest that the main constraints on bruchid oviposition behaviour are the amount of time available for laying eggs and the number of other females ovipositing. However, additional qualitative predictions indicate that the number of eggs available to the female may also constrain clutch size evolutionarily. The usefulness of static optimality models for examining clutch size decisions in insects is discussed in the context of these results.
The evolution of reaction norms: simple models for age and size at maturity
Authors: Berrigan David , Koella Jacob C.
Published: December 2004

This paper presents a simple model for the evolution of reaction norms for age and size at maturity that predicts reaction norms with a variety of shapes. Using realistic parameter values the model predicts reaction norms close to those observed in Drosophila. The major assumptions of the model are: 1) that net reproductive rate is maximized, 2) that growth is determinate, and 3) that mortality rates are independent of age and size at maturity. If, additionally, juvenile mortality is uncorrelated with a growth coefficient, k, the model predicts that selection favors maturation later at a smaller size when k is reduced by environmental factors and that decreased juvenile mortality leads to delayed maturity. These two predictions conform with those found by previous models using other measures of fitness. Correlations between k and juvenile mortality can change the shape of the predicted reaction norm. Depending on the precise form of the correlation, the model can predict done‐ or bowl‐shaped reaction norms and can predict delayed or earlier maturity as k decreases. These shapes are qualitatively different from those predicted by previous models that used different fitness measures. Systematic estimates of the parameter values for this and for related models are required to determine the appropriate fitness measure for models of reaction norms.
Selection on the genetical and environmental components of tarsal growth in juvenile willow tits (Parus montanus)
Authors: Thessing A. , Ekman J.
Published: December 2004

We studied selection on tarsus length among first year willow tits Parus montanus in relation to environmental and genetical influences on growth. The main environmental influence on growth was a cohort effect. We also found a substantial heritable component of phenotypic variation for tarsus length (h2 = 0.61), and crossfostering in one year showed no shared environment effect which could account for parent/offspring resemblance. The deteriorating conditions for growth later in the season did not confound our heritability estimates as the time of laying was not correlated to parent size, and no maternal effects operating through egg size were found. We tested for selection during the summer dispersal phase by comparing tarsus length among fullgrown pulli (age 14 days, controlled by repeated measurements of the same individuals later during breeding and the ensuing winter) and the tarsus length of the first year cohort in autumn composed of a mixture of locally born birds remaining within our study area after the dispersal phase and immigrants born outside the study site. Following a season with poor nestling growth, birds with short tarsi were selected against when underweight, suggesting that growth condition is the target of selection. Such selection on those individuals which show the strongest environmental influence on phenotypic variation will reduce the potential for an evolutionary response to selection.
Metapopulations: an arena for local speciation
Authors: Levin Donald A.
Published: December 2004

Speciation in many groups of plants and animals is thought to occur in single, isolated populations. Recent investigations of metapopulation longevity and genetic structure indicate that metapopulations have demographic and genetic properties which may be more conducive for local speciation than properties of single populations. It is argued that metapopulations may persist longer than single populations, that the former may retain genetic variation more readily, and that the former offers more opportunity for genomic reorganization.
The effects of relatedness on progeny sex ratio in spider mites
Authors: Roeder C. , Harmsen R. , Mouldey S.
Published: December 2004

Theory predicts that optimal sex allocation in subdivided populations is dependent on the genetic relatedness among competing offspring such that when relatedness is high, progeny sex allocation should be more biased than when relatedness is low. In the laboratory we compared the progeny sex ratio of four groups of five ovipositing females of various presumed degrees of relatedness (sisters of inbred laboratory population, sisters of outbred field population, non‐sisters of the same field population and non‐sisters each from a different, geographically distant field population). We found a greater female bias in the progeny of inbred sisters than for sisters from the field population; the progeny sex ratio was also more strongly female biased for sisters than for non‐sisters from the field population. These differences in sex ratio are in line with theoretical predictions. Our results indicate that spider mites are capable of some method of discrimination between kin and non‐kin.
Placental hormones, genomic imprinting, and maternal—fetal communication
Authors: Haig D.
Published: December 2004

Placental hormones are produced by one genetic individual (the fetus) to act on the receptors of another genetic individual (the mother). Mothers are probably able to extract some information from placental hormones, but this information may be limited to a crude measure of fetal vigor. Placental hormones are most easily interpreted as fetal attempts to manipulate maternal metabolism for fetal benefit. An evolutionary model is presented for a hypothetical hormone that increases the nutrient content of maternal blood. The model predicts that, at an evolutionary equilibrium, the hormone will be produced solely by the mother or solely by the placenta, but not by both. If the gene for the hormone is subject to genomic imprinting, the paternally‐derived allele will be active and the maternally‐derived allele will be silent. Hormone production benefits the members of the mother's current litter at some cost to future litters. Therefore, paternity changes between litters increase the level of hormone production. On the other hand, offspring that produce less of the hormone than litter‐mates share the benefits but have lower costs. Therefore, multiple paternity within litters reduces the level of hormone production.
Origin and radiation of the house mouse: mitochondrial DNA phylogeny
Authors: Boursot P. , Din W. , Anand R. , Darviche D. , Dod B. , Von Deimling F. , Talwar G. P. , Bonhomme F.
Published: December 2004

On the basis of patterns of allele frequency variation in nuclear genes (Din et al., in press) it has been proposed that the house mouse M. musculus originated in the northern Indian subcontinent, from where it radiated in several directions to form the well‐described peripheral subspecies (M. m. domesticus, M. m. musculus and M. m. castaneus). Here we use a mitochondrial DNA (mtDNA) phylogeny to test this hypothesis and to analyse the historical and demographic events that have accompanied this differentiation. This marker also provides a powerful means to check for genetic continuity between the central and peripheral populations. We studied restriction site polymorphism of samples from India and the Middle East as well as samples from the rest of Eurasia and northern Africa. M. m. domesticus and M. m. musculus are both monophyletic for mtDNA and belong to the subspecies‐specific mtDNA lineages that have been described previously. Average nucleotide diversity is low in M. m. musculus (0.2–5%). It is not only higher in M. m. domesticus (0.7–0.9%) but the distribution of pairwise divergence is wider, and the rate of evolution in this branch appears to be higher than in M. m. musculus. The nucleotide diversity found in M. m. castaneus (0.4%) is due to the existence of two rather divergent linages with little intralineage variation. These two lineages are part of a diversified bush of the phylogenetic tree that also comprises several previously undescribed branches and includes all samples from the northern Indian subcontinent and Iran. The degree of diversity found in each of the samples from this region is high (1.2–2.4%) although they come from small geographic areas. This agrees well with the idea that the origin of the radiation was in the northern Indian subcontinent. However, as neither haplotypes on the M. m. domesticus nor on the M. m. musculus branches were found in this region, there appear to be important phylogeographic discontinuities between this central region and these peripherial subspecies. On the basis of the present result and the nuclear data (Din et al., in press), we propose that M. musculus originated in the north of the indian subcontinent. Our calibration of the evolutionary rate of mtDNA in mice suggests that the mouse settlement in this region could be as old as 900 000 years. Possibly from there, a first radiation could have reach the Middle East and the Caspian Sea, where the M. m. domesticus and M. m. musculus lineages, respectively, would have started to differentiate a few hundred thousand years ago, and from where they could have colonised the peripheral part of their ranges only recently.M. m. castaneus appears from its mtDNA to be recent offshoot of the northern Indian population. This multiple and gradual radiation ultimately led to recent peripheral secondary contacts, such as the well‐known European hybrid zone.
Origin and radiation of the house mouse: clues from nuclear genes
Authors: Din W. , Anand R. , Boursot P. , Darviche D. , Dod B. , Jouvin‐Marche E. , Orth A. , Talwar G.P. , Cazenave P.‐A. , Bonhomme F.
Published: December 2004

Although quite a lot is known about the genetic structure of the polytypic species Mus musculus at the periphery of its range, the centre of origin and dispersion of the species remains unknown. To investigate the amount of genetic subdivision that occurs in the central parts of its range, we analysed the genetic variation in four new samples of mice coming from Iran, Pakistan, northern and southern India using 35 autosomal protein loci and restriction fragment length polymorphisms of three genes of the Vβ gene complex of the immune system. The variation was then compared with that found in the subspecies occupying the peripheral regions of the species range. The two samples from the northern part of the Indian subcontinent were shown to be more heterozygous than the samples from any of the other regions. They also contain the majority of the alleles that exist in the differentiated subspecies at the periphery of the species range. A neighbour‐joining analysis on Nei's genetic distances and a factorial analysis of correspondences on the allelic composition of each sample both place the Pakistani and Indian populations in a phylogenetically and genetically central position compared to the peripheral subspecies. These results suggest that the populations in this geographically central area have retained most of the ancestral polymorphisms, which in turn indicates that the Indian subcontinent is probably the cradle of the species. The nature of the genetic relationships between the various populations throughout the species range and the possibility that they form an incipient ring species are also discussed. Our results are in agreement with the classical model of geographic differentiation where genetic divergence in allopatry is considered to be the prime cause of subspecies formation that may eventually lead to partial reproductive isolation on secondary contact.
Phenotypic plasticity in age and size at maturity and its effects on the integrated phenotypic expressions of life history traits of Cardamine flexuosa (Cruciferae)
Authors: Kudoh H. , Ishiguri Y. , Kawano S.
Published: December 2004

We analyzed variation in phenotypic plasticity of life history traits between two Cardamine flexuosa populations based on differences in plasticity of age and size at maturity. C. flexuosa (Cruciferae) is a facultative, vernalization‐sensitive, long‐day annual, and its phenology and the phenotypic expressions of many life history traits are largely controlled by photoperiod and vernalization in natural populations. We used plants from two populations which differed in their responses to chilling and photoperiod treatments. The timing of developmental processes was changed by controlling temperature and photoperiod regimes in growth chambers. Plasticity in size at maturity was analyzed as changes in a growth trajectory using two parameters, age at maturity (Δt) and growth rate (k). Both traits showed plasticity, but differences between the populations were found mostly for Δt. Distinctive differences in size at maturity of individuals in the two populations were mainly due to different amounts of plasticity in Δt. Variations in plasticity of nine other life history traits and their associations to age and size at maturity were also analyzed. Variation for eight of the traits can be described, at least in part, as a function of age and size at maturity for both populations, and most of the variation in the total number of seeds was explained by age and size at maturity. Only age at maturity had any effect on changes in resource allocation. The nine life history traits were integrated through associated character expressions with age and size at maturity. Changes in the association between a trait and age and/or size at maturity were rather conservative compared to changes in the plasticity of a trait between the two populations. Associations with age and size at maturity are mostly explicable in terms of inherent relationships in the developmental processes, and they may limit the ecological range expansion and the adaptive evolution of plasticity in C. flexuosa. The negative correlation between reproductive allocation and age at maturity can be a cost of delaying maturation in C. flexuosa.
Ejaculate size in bushcrickets: the importance of being large
Authors: Wedell N.
Published: December 2004

Sexual size dimorphism is common in animals. Females, which often experience increased fecundity with size, are generally the larger sex. In males, the pre‐copulatory advantages of large size have been extensively investigated. However, in polyandrous species, large male size may also be advantageous after copulation due to sperm competition. Male size co‐varies with ejaculate size and increased fertilization success in many insects. Large male size can also be important for production of nuptial gifts enhancing female fecundity. In this study, the relative importance of male size for ejaculate and nuptial gift production is assessed in 20 bushcricket species (Orthoptera: Tettigoniidae). Relative male size is found to correlate with increased ejaculate size across taxa. In contrast, no association is found between relative male size and the size or quality of the nuptial gift. These findings indicate that selection for increased ejaculate volumes as a response to sperm competition may act to promote large male size in insects.
The seasonal timing of oviposition in sand lizards (Lacerta agilis): why early clutches are better
Authors: Olsson M. , Shine R.
Published: December 2004

We studied a population of sand lizards (Lacerta agilis) near the northern edge of the species' range in coastal Sweden. We captured, marked, released and recaptured 98 adult female lizards over 5 years. Hatchlings from 146 laboratory‐incubated clutches (1279 eggs) from field‐caught gravid females were measured, weighed, marked and released at the study site. Female sand lizards usually laid only a single clutch of 4 to 15 eggs each year, but varied considerably in the time of year at which they laid their eggs. Oviposition dates shifted between years depending on weather (basking opportunities), but the relative timing of oviposition was consistent within a given female from year‐to‐year. The first females to oviposit each year were large animals in good physical condition, that had grown rapidly in previous years. “Early” clutches were larger than “later” clutches, had higher hatching success, and tended to have higher post‐hatching survival rates. Offspring from early clutches were larger than “later” hatchlings, and differed in body proportions (probably because seasonal changes in maternal temperatures directly modified offspring phenotypes).

Overall, our study documents several strong correlates of the timing of oviposition, and suggests that variation in this trait among females has strong fitness consequences, perhaps related to maternal “quality”. The correlations we observed between oviposition date and other traits that have been invoked as determinants of hatchling survival in reptiles (e.g., hatchling size, body shape, opportunities for multiple mating by the mother) suggest that hypotheses advocating simple causal connections between these traits and hatchling success should be viewed with caution.
Fluctuating asymmetry in the honey bee, Apis mellifera: effects of ploidy and hybridization
Authors: Smith D. R. , Crespi B. J. , Bookstein F. L.
Published: December 2004

We present a new measure of morphological asymmetry that avoids most of the statistical problems inherent in character‐by‐character analysis of size or shape. The method is an application of Procrustes analysis, which computes best‐fitting super‐positions of configurations of landmarks to the left and right sides of a single specimen. The Procrustes method combines subtle deviations in all aspects of the landmark configuration into one net asymmetry score. Directional asymmetry is separated from fluctuating asymmetry in a simple partition of a net sum‐of‐squares, and geometrical details of either component can be inspected by traditional methods of multivariate statistical analysis of landmarks.

We demonstrate this method in a comparison of wing venation asymmetry in male (haploid) and female (diploid) honey bees (Apis mellifera). In addition we investigate the effects of ploidy and inter‐subspecies hybridization on asymmetry and wing venation abnormalities, using the subspecies A. m. mellifera, A. m. carnica, and the hybrid strain “Nigra”. Results suggest that while the haploid males showed a higher frequency of wing venation abnormalities and greater total asymmetry than the diploid females, most of the asymmetry difference between males and females was in the form of directional, not fluctuating, asymmetry. Hybrid females had a higher frequency of wing venation abnormalities than females of either subspecies, but there were no significant differences in the mean level of asymmetry among females of A. m. mellifera, A. m. carnica and hybrid Nigra. Hybrid males had higher absolute frequency of wing venation abnormalities and asymmetry than males of either subspecies. However the mean frequency of venation abnormalities did not differ significantly between Nigra and A. m. carnica males, and mean asymmetries were not significantly different between Nigra and A. m. mellifera males. We discuss the relationship which is assumed to exist between developmental stability and fluctuating asymmetry in light of our result.
In situ proton NMR analysis of α‐alkynoate biotransformations
Authors: Brecker Lothar , Petschnigg Julia , Depiné Nicole , Weber Hansjörg , Ribbons Douglas W.
Published: December 2004

Only 2% of the known natural products with acetylenic bonds are α‐alkynoates. Their polarized, conjugated triple bond is an optimal target for an enzymic hydration. Therefore they are good substrates for the enzymes involved in metabolism of acetylenic compounds, resulting in products that are suitable for bacterial growth. We isolated a Pseudomonas putida strain growing on 2‐butynedioate as well as on propynoate, and determined the metabolic pathways of these two α‐alkynoates. The triple bonds in both compounds were initially hydrated and 2‐ketobutandioate as well as 3‐ketopropanoate were formed. These two β‐keto acids were decarboxylated resulting in pyruvate and acetaldehyde, respectively. Pyruvate was further hydrolysed mainly to acetate and formate, whereas minor amounts were reduced to lactate. In the other biotransformation, acetaldehyde was oxidized to acetate accompanied by the reduction of 3‐ketopropanoate to 3‐hydroxypropanoate. Analyses of these metabolic processes were performed by in situ1H‐NMR spectroscopy in 1H2O, although the substrates, propynoate and 2‐butynedioate, carried only one or even no detectable protons, respectively. However, while protons from the solvent are incorporated in the course of the pathway, the metabolites can be detected and identified. Therefore a detailed determination of the metabolic process is possible.