Life History (life + history)

Distribution by Scientific Domains
Distribution within Life Sciences

Kinds of Life History

  • alternative life history
  • complex life history
  • early life history
  • host life history
  • human life history
  • individual life history
  • similar life history
  • species life history

  • Terms modified by Life History

  • life history attribute
  • life history change
  • life history characteristic
  • life history data
  • life history evolution
  • life history parameter
  • life history pattern
  • life history plasticity
  • life history stage
  • life history strategy
  • life history theory
  • life history trade-off
  • life history trait
  • life history type
  • life history variation

  • Selected Abstracts


    EVOLUTION, Issue 7 2010
    Hélène Magalon
    In parasites with mixed modes of transmission, ecological conditions may determine the relative importance of vertical and horizontal transmission for parasite fitness. This may lead to differential selection pressure on the efficiency of the two modes of transmission and on parasite virulence. In populations with high birth rates, increased opportunities for vertical transmission may select for higher vertical transmissibility and possibly lower virulence. We tested this idea in experimental populations of the protozoan Paramecium caudatum and its bacterial parasite Holospora undulata. Serial dilution produced constant host population growth and frequent vertical transmission. Consistent with predictions, evolved parasites from this "high-growth" treatment had higher fidelity of vertical transmission and lower virulence than parasites from host populations constantly kept near their carrying capacity ("low-growth treatment"). High-growth parasites also produced fewer, but more infectious horizontal transmission stages, suggesting the compensation of trade-offs between vertical and horizontal transmission components in this treatment. These results illustrate how environmentally driven changes in host demography can promote evolutionary divergence of parasite life history and transmission strategies. [source]


    EVOLUTION, Issue 5 2002
    Bernard J. Crespi
    Abstract The selective pressures involved in the evolution of semelparity and its associated life-history traits are largely unknown. We used species-level analyses, independent contrasts, and reconstruction of ancestral states to study the evolution of body length, fecundity, egg weight, gonadosomatic index, and parity (semelparity vs. degree of iteroparity) in females of 12 species of salmonid fishes. According to both species-level analysis and independent contrasts analysis, body length was positively correlated with fecundity, egg weight, and gonadosomatic index, and semelparous species exhibited a significantly steeper slope for the regression of egg weight on body length than did iteroparous species. Percent repeat breeding (degree of iteroparity) was negatively correlated with gonadosomatic index using independent contrasts analysis. Semelparous species had significantly larger eggs by species-level analysis, and the egg weight contrast for the branch on which semelparity was inferred to have originated was significantly larger than the other egg weight contrasts, corresponding to a remarkable increase in egg weight. Reconstruction of ancestral states showed that egg weight and body length apparently increased with the origin of semelparity, but fecundity and gonadosomatic index remained more or less constant or decreased. Thus, the strong evolutionary linkages between body size, fecundity, and gonadosomatic index were broken during the transition from iteroparity to semelparity. These findings suggest that long-distance migrations, which increase adult mortality between breeding episodes, may have been necessary for the origin of semelparity in Pacific salmon, but that increased egg weight, leading to increased juvenile survivorship, was crucial in driving the transition. Our analyses support the life-history hypotheses that a lower degree of repeat breeding is linked to higher reproductive investment per breeding episode, and that semelparity evolves under a combination of relatively high juvenile survivorship and relatively low adult survivorship. [source]


    JOURNAL OF PHYCOLOGY, Issue 6 2004

    The phenology, life history, ultrastructure of reproductive structures, and molecular phylogeny using rbcL and rDNA (5.8S, internal transcribed spacer 2, and partial 26S) gene sequences of Stschapovia flagellaris, endemic to the northwestern Pacific Ocean, were studied. This species was first classified in the order Delamareales together with Delamarea, Coelocladia, and Cladothele. Those three genera, however, were later transferred to Dictyosiphonales, whereas the systematic position of Stschapovia remained unclear. At Abashiri, Hokkaido, Japan, the species regenerated by forming a new erect thallus from a perennial crustose holdfast or by presumably parthenogenetic development of eggs released from the erect thallus. There was no alternation of generations. In winter, the monoecious erect thallus formed reproductive structures (i.e. plurilocular antheridia and oogonia) in the thickened part of the thallus. Sperm had a chloroplast with an eyespot and a long anterior and short posterior flagellum. Eggs contained numerous disc-shaped chloroplasts, physodes, and vacuoles. Neither sexual attraction of the presumptive sperm by eggs nor their sexual fusion was observed. Molecular phylogenetic analyses revealed the closest phylogenetic relationship between Stschapovia and Halosiphonaceae, and they grouped with Phyllariaceae and Tilopteridaceae (Tilopteridales s. s.). Stschapovia and Tilopteridaceae have several important morphological similarities: chloroplasts lacking pyrenoids, lack of sexual reproduction despite the release of obvious sperm, occurrence of monoecious gametophytes, and similarity in the early developmental pattern of the erect thallus. In conclusion, we propose the establishment of the new family Stschapoviaceae to accommodate Stschapovia and the placement of the family in the order Tilopteridales together with Tilopteridaceae, Halosiphonaceae, and Phyllariaceae. [source]

    Primate Life Histories and Socioecology

    ETHOLOGY, Issue 12 2003
    D. B. Meikle
    No abstract is available for this article. [source]

    Introduction to special issue on "Trade-Offs in Female Life Histories: Integrating Evolutionary Frameworks"

    Rebecca Sear
    First page of article [source]

    Contrasting Patch Residence Strategy in Two Species of Sit-and-Wait Foragers Under the Same Environment: A Constraint by Life History?

    ETHOLOGY, Issue 2 2005
    Tadashi Miyashita
    The present study explored the significance of life history constraints on patch residence strategy by using two congeneric web spider species living in the same habitat. Nephila maculata had a large body size but had a shorter developmental period compared with N. clavata, indicating that N. maculata should have a greater foraging efficiency to reach maturity and reproduce. Residence time at web-sites in N. maculata was shorter than that in N. clavata, irrespective of the season. However, supplementation of food to N. maculata increased residence time, suggesting that it searches web-sites with higher prey intake. Investment of web materials, an important trait influencing web relocation frequency, was not greater in N. maculata. In addition, microhabitat and prey size did not differ significantly after controlling for the effect of body size. Because N. maculata needs to attain a large body size in a shorter period of time, this species appears to take a risk of moving patches to seek high quality web-sites. [source]

    The relationship between history of violent and criminal behavior and recognition of facial expression of emotions in men with schizophrenia and schizoaffective disorder

    Elisabeth M. Weiss
    Abstract Social psychological research underscores the relation between aggression and emotion. Specifically, regulating negative affect requires the ability to appraise restraint-producing cues, such as facial signs of anger, fear and other emotions. Individuals diagnosed with major mental disorders are more likely to have engaged in violent behavior than mentally healthy members of the same communities. We examined whether violent and criminal behavior in men with schizophrenia is related to emotion recognition abilities. Forty-one men with schizophrenia underwent a computerized emotion discrimination test presenting mild and extreme intensities of happy, sad, angry, fearful and neutral faces, balanced for gender and ethnicity. History of violence was assessed by the Life History of Aggression Scale and official records of arrests. Psychopathology was rated using the Positive and Negative Symptom Scale. Criminal behavior was associated with poor emotion recognition, especially for fearful and angry facial expressions. History of aggression was also associated with more severe positive symptoms and less severe negative symptoms. These findings suggest that misinterpretation of social cues such as angry and fearful expression may lead to a failure in socialization and adaptive behavior in response to emotional situation, which may result in a higher number of criminal arrests. Aggr. Behav. 32:1,8, 2006. © 2006 Wiley-Liss, Inc. [source]

    133 Studies on the Life History of the Portuguese Red Alga Porphyra Dioica (Brodie and Irvine) Under Varying Environmental Conditions

    R. Pereira
    The life history of Porphyra dioica collected in Porto, Portugal, was investigated under laboratory conditions. This is one of the most common Porphyra species on the North Coast of Portugal and can be found throughout the year. Field studies showed higher percentage cover, from 23 to 66%, during February through May. Varying temperature, light intensities and photoperiods were tested. The zygotospores germinated faster at 15°C, and at 25 ,mol m,2·s,1. Growth rate of the conchocelis was affected by temperature rather than by photoperiod. In the three photoperiods tested, growth rate was always higher at 15°C, under 25 to 75 ,mol m,2·s,1, although not significantly different from that at 20° C. Difference between these two temperatures and 5 and 10°C was significant. Conchosporangia formation was higher in 15°C and at short-day, 8:16, Light:Dark and 25 to 75 ,mol m,2·s,1 and was almost non-existent in free floating conditions. Optimal conditions for conchosporangia maturation, 15° C, 8:16, Light:Dark and 5 to 25 ,mol m,2·s,1 also promoted spore release after 18 weeks. Aeration appeared to be crucial for normal blade development. No archeospores were observed. The first findings of the optimal conditions for growth of the gametophyte stage will also be discussed. [source]

    135 Life History and Ecology of Trentepohliaceae (Chlorophyta) in the West of Ireland

    F. Rindi
    Species of subaerial green algae of the family Trentepohliaceae are common in tropical and temperate regions. Despite nearly two centuries of investigations, several important aspects of their biology (such as life history and taxonomic relationships of some species) are still poorly understood. In western Ireland, the abundance of Trentepohliaceae is a peculiar feature of the subaerial algal vegetation. Six species are present (Phycopeltis arundinacea, Printzina lagenifera, Trentepohlia abietina, T. aurea, T. iolithus and T. umbrina). Life history and phenology of these were examined by extensive field and culture studies. In contrast to most other subaerial algae, the Trentepohliaceae show a generally strict substratum-specificity in western Ireland. T. iolithus, in particular, is remarkable for its occurrence on concrete walls, where it may produce extensive dark-red growths. Our observations suggest that general statements about the life history of Trentepohlia should be reconsidered critically. There is no evidence that in Irish populations a regular alternation of isomorphic gametophytes and sporophytes takes place; biflagellate swarmers (usually considered gametes) behave as asexual spores and reproduce the same morphological phase. No fusion of gametes was observed and a detailed examination of the literature concerning the genus shows that this phenomenon is extremely rare. A combination of studies based on different types of data (molecular data, examination of very large numbers of field samples, chromosome numbers, culture studies) is considered fundamental to any definitive clarification of the taxonomy and life history of Trentepohlia. [source]

    Life histories of Eucalanus bungii and Neocalanus cristatus (Copepoda: Calanoida) in the western subarctic Pacific Ocean

    Abstract Life cycles of the large suspension-feeding copepods, Eucalanus bungii and Neocalanus cristatus were investigated by seasonal sampling in the western subarctic Pacific. Eucalanus bungii has a diapause from August to March at copepodite stages between copepodite 3 (C3) and C6 female. We propose that individuals with early birth dates are young of overwintering C5 and C6-females that develop to C4 in their birth year, while individuals with late birth dates are young of overwintering C4 that develop to C3 in their birth year. Thus, a majority of the population has annual generations alternating with biennial generations. Neocalanus cristatus showed life history almost identical to the population in the Alaskan gyre. Timing of the life cycle in N. cristatus is very close to that in the eastern subarctic gyre, but that of E. bungii is 2 months earlier than in the eastern subarctic. This difference is probably caused by the timing difference in the maximum primary production in the two areas and the plasticity of the life cycle strategy in E. bungii. [source]

    Life history and population size variability in a relict plant.

    Different routes towards long-term persistence
    ABSTRACT A central tenet of conservation biology is that population size affects the persistence of populations. However, many narrow endemic species combine small population ranges and sizes with long persistence, thereby challenging this tenet. I examined the performance of three different-sized populations of Petrocoptis pseudoviscosa (Caryophyllaceae), a palaeoendemic rupicolous herb distributed along a small valley in the Spanish Pyrenees. Reproductive and demographic parameters were recorded over 6 years, and deterministic and stochastic matrix models were constructed to explore population dynamics and extinction risk. Populations differed greatly in structure, fecundity, recruitment, survival rate, and life span. Strong differentiation in life-history parameters and their temporal variability resulted in differential population vulnerability under current conditions and simulated global changes such as habitat fragmentation or higher climatic fluctuations. This study provides insights into the capacity of narrow endemics to survive both at extreme environmental conditions and at small population sizes. When dealing with species conservation, the population size,extinction risk relationship may be too simplistic for ancient, ecologically restricted organisms, and some knowledge of life history may be most important to assess their future. [source]

    Life history in a model system: opening the black box with Arabidopsis thaliana

    ECOLOGY LETTERS, Issue 7 2009
    C. Jessica E. Metcalf
    Abstract A broad research programme in Arabidopsis thaliana has provided estimates of selection on specific alleles in specific contexts, and identified geographic patterns of alleles in genes linked to timing of flowering. A closely related field has successfully captured many key axes of the evolution of timing of flowering in other monocarpic species through statistical and demographic modelling of large empirical databases. There has as yet been no synthesis between these two fields. Here we examine ways in which the two fields inform each other, and how this synergy will shape our knowledge of life-history evolution as a whole. [source]

    Life history of the bird cherry-oat aphid, Rhopalosiphum padi, on transgenic and non-transformed wheat challenged with Wheat streak mosaic virus

    Edgardo S. Jiménez-Martínez
    Abstract The life history of the bird cherry-oat aphid, Rhopalosiphum padi (L.) (Hemiptera: Aphididae), was studied via laboratory assays on Wheat streak mosaic virus (WSMV)-infected and non-infected transgenic and non-transformed wheat [Triticum aestivum L. (Poaceae)]. Although R. padi is not a WSMV vector, it is known to colonize WSMV-infected wheat plants. Two transgenic soft white winter wheat genotypes, 366-D03 and 366-D8, that express the WSMV coat protein gene, and the WSMV-susceptible non-transformed cultivar Daws were tested. All genotypes showed disease symptoms when infected with WSMV. Whereas plant height was significantly reduced on virus-infected compared to non-infected plants of all genotypes, virus-infected transgenic plants exhibited lower virus titer and lower disease rating scores than Daws. No significant effects of WSMV infection or genotypes were observed on the length of R. padi nymphal development period, nor on their pre-, and post-reproductive periods. Rhopalosiphum padi reproductive period was significantly longer on Daws infected with WSMV than on non-infected plants of this cultivar. In contrast, there were no significant differences in length of R. padi reproductive period between virus-infected and non-infected transgenic plants within a genotype. Rhopalosiphum padi daily fecundity was significantly lower and adult longevity significantly longer on virus-infected than on non-infected plants of all genotypes. Total aphid fecundity and intrinsic rate of increase were not significantly different among treatments. The percentage of winged aphids that developed was greater on WSMV-infected compared to non-infected plants within a genotype. Results indicate that both virus infection status of plants and wheat genotype influence the life history of R. padi. [source]

    Life history and host specificity of the Japanese flea beetles Trachyaphthona sordida and T. nigrita (Coleoptera: Chrysomelidae), potential biological control agents against skunk vine, Paederia foetida (Rubiaceae), in the southeastern parts of the United States and Hawaii

    Chie OKAMOTO
    Abstract Skunk vine, Paederia foetida (Rubiaceae), is native to Asia and has been recognized as an invasive weedy vine of natural areas in Florida and Hawaii. Two insects, Trachyaphthona sordida and Trachyaphthona nigrita (Coleoptera: Chrysomelidae) from Japan are being considered as potential biological control agents against skunk vine. To gather fundamental information on their biology, we carried out field surveys and laboratory experiments in Kyushu, southern Japan, between 2003 and 2006. We found that T. sordida is commonly distributed in Kyushu and T. nigrita is restricted to the southern parts of Kagoshima Prefecture on the southern part of Kyushu. These species are fundamentally univoltine and adults appear in late April to early July. Trachyaphthona sordida overwinters as mature larvae and T. nigrita as mature larvae or rarely as adults. Larvae of both species feed on fine roots of P. foetida in the field and Serissa foetida (Rubiaceae) under rearing conditions, and they appear to have tribe-level host specificity in their host range. On the basis of these results, we suggest that both species are suitable as biological control agents. [source]

    Life history and production of Agapetus quadratus (Trichoptera: Glossosomatidae) in a temporary, spring-fed stream

    FRESHWATER BIOLOGY, Issue 6 2005
    Summary 1. The life history and trophic basis of production of the caddisfly grazer Agapetus quadratus were studied in the torrent Gorg Blau, a spring-fed stream on the island of Majorca that dries annually during summer. 2. Quantitative random samples were taken every 2,3 weeks during an annual surficial flow period, from November 2000 to mid-July 2001. Instars of field-collected larvae were determined by measurements of head width and pronotum length, and the sex of all pupae was determined to study sexual dimorphism and sex ratio. 3. Stage-frequency histograms suggested a trivoltine population, with an average cohort time of 4 months. Larval development was asynchronous, with continuous growth and overlapping generations. Recruitment peaks were identified in mid-November, early March and late June, indicative of winter, spring and summer generations. On average, females were larger than males and the mean sex ratio was 2 : 3 (females : males). Population densities and biomasses derived from the field data were used to calculate production and turnover rate. 4. Annual production of A. quadratus in the torrent Gorg Blau (4.80 g dry mass m,2 year,1) was the highest ever reported for the genus, being comparable with that estimated for some insects with rapid development and multiple cohorts. 5. Estimates of production of A. quadratus were combined with foregut content analysis to estimate the fraction of total production derived from the principal food sources: algae and organic detritus. Algae supported a major proportion of the production of this grazer. 6. The low density of predators characteristic of many temporary streams, and the small amplitudes in discharge and temperature during most of the wet period that characterise the spring habitats might allow high levels of grazer production in this particular Mediterranean stream. [source]

    Life history correlates of oxidative damage in a free-living mammal population

    FUNCTIONAL ECOLOGY, Issue 4 2009
    Daniel H. Nussey
    Summary 1Reactive oxygen species, produced as a by-product of normal metabolism, can cause intracellular damage and negatively impact on cell function. Such oxidative damage has been proposed as an evolutionarily important cost of growth and reproduction and as a mechanistic explanation for organismal senescence, although few tests of these ideas have occurred outside the laboratory. 2Here, we examined correlations between a measure of phospholipid oxidative damage in plasma samples and age, growth rates, parasite burden and investment in reproduction in a population of wild Soay sheep on St. Kilda, Scotland. 3We found that, amongst females of different ages, lambs had significantly elevated levels of oxidative damage compared to all other age classes and there was no evidence of increasing damage with age amongst adult sheep. 4Amongst lambs, levels of oxidative damage increased significantly with increasing growth rates over the first 4 months of life. Neither mean damage nor the effect of growth rate on damage differed between male and female lambs. 5Amongst adult female sheep, there was no evidence that body mass, current parasite burden or metrics of recent and past reproductive effort significantly predicted oxidative damage levels. 6This study is the first to examine age variation in an assay of oxidative damage and correlations between oxidative damage, growth and reproduction in a wild mammal. Our results suggest strong links between early conditions and oxidative damage in lambs, but also serve to highlight the limitations of cross-sectional data for studies examining associations between oxidative stress, ageing and life history in free-living populations. [source]

    Life history of a mule (c. 160 AD) from the Roman fort Biriciana/Weißenburg (Upper Bavaria) as revealed by serial stable isotope analysis of dental tissues

    T. E. Berger
    Abstract The presence of the osseous remains of at least four mules in a garbage dump at the Roman fort of Biriciana near the town of Weißenburg, Upper Bavaria, dating to c. 160 AD, raised the question as to whether mule breeding was already performed to the north of the Alps during the Middle Roman Empire, or whether these animals still had to be imported from the Mediterranean. Serial analyses of the dental enamel and dentine of a lower fourth premolar and the surrounding alveolar bone of a mandible of a mule in terms of stable strontium isotopic ratios of the apatite, and stable carbon and oxygen isotope ratios of the structural carbonate, were carried out to test whether this individual moved long distances during its lifetime. Since isotopic ratios obtained by serial analysis can be correlated with consecutive ontogenetic stages, it can be assumed that this particular individual experienced significant changes in terms of diet and environmental parameters after its eighth year of life. These changes included a period of residence in a region of high altitude, most likely the Alps considering the location of the Roman fort where the mule was found. The isotopic data obtained do not contradict the assumption that this animal was bred and raised in northern Italy, to frequent later in its adult life the Alps and finally perish at Biriciana/Weißenburg. Copyright © 2008 John Wiley & Sons, Ltd. [source]

    Life history of Littorina scutulata and L. plena, sibling gastropod species with planktotrophic larvae

    Paul A. Hohenlohe
    Abstract. The intertidal, sibling species Littorina scutulata and L. plena (Gastropoda, Proso-branchia) are sympatric throughout most of their ranges along the Pacific coast of North America. Both species release disc-shaped, planktonic egg capsules from which planktotrophic veliger larvae hatch. Here I review existing data and present new observations on these species' life history, including age at first reproduction, spawning season, maximum fecundity rates, capsule morphology, egg size and number, pre-hatching development, larval growth at three food concentrations, potential settlement cues, planktonic period, and protoconch size. Previous classification of egg capsule morphologies used to distinguish the species is inaccurate; instead, capsules can be categorized into three types of which each species may produce two. Females of L. scutulata produced capsules with either two rims of unequal diameter or one rim, while females of L. plena produced capsules with one rim or two rims of nearly equal diameter. Females of each species spawned sporadically from early spring to early fall in Puget Sound. Larvae of L. plena hatched one day earlier than those of L. scutulata, and both species grew fastest in the laboratory at intermediate food concentrations. Larvae metamorphosed in the presence of a variety of materials collected from their adult habitat, including conspecific adults, algae, rocks, and barnacle tests. This is the first report of planktotrophic larvae in this genus metamorphosing in the laboratory. The total planktonic period of 8 larvae of L. scutulata raised in the laboratory was 37,70 days, and a single larva of L. plena metamorphosed after 62 days. Protoconch diameter of shells collected from the field was 256,436 ,m and did not differ significantly between the species. Previous allozyme and mitochondrial DNA work has suggested high levels of genetic variability in both species and greater genetic population structure in L. plena, despite the long spawning season and long-lived larvae in both species. The interspecific life history differences described here appear insufficient to produce consistent differences in gene flow patterns. [source]

    Life history and fitness consequences of ectoparasites

    Patrick S. Fitze
    Summary 1For iteroparous organisms life-history theory predicts a trade-off between current and future reproduction, and therefore the evolution of host responses to current parasite infestation that will maximize lifetime reproductive success. The parasite-induced variation in reproductive success is thus not the net result of parasite infestation alone, but the parasite-mediated outcome of optimal resource allocation among current and future reproductive events. Understanding the importance of parasites for the evolution of host life history therefore requires an experimental investigation of the effects of parasites over the host's life span. Such studies are currently scant. 2We manipulated the load of an ectoparasite, the hen flea (Ceratophyllus gallinae), in the nests of its most common host, the great tit (Parus major), over a period of 4 years and recorded, the components of current and future reproductive success including survival, divorce, breeding dispersal and various reproductive parameters. Finally we assessed, for females only as paternity of males was unknown, the lifetime reproductive success as a close correlate of Darwinian fitness. 3For current reproduction, our experiment demonstrates that parasites reduce current reproductive success via an increase in the probability of nest failure during incubation and the nestling period. In the presence of fleas, clutch size and the number of fledglings were reduced while the incubation and the nestling period were prolonged. Thus parasitism led to an increase in parental effort but nevertheless reduced current reproductive success. 4For future reproduction, the experiment shows that females breeding in infested nests dispersed over longer distances between breeding attempts. The divorce rate following infestation, the probability of breeding locally in the future and residual reproductive success were not affected significantly by ectoparasites. The study thus suggests that hen fleas play a minor role in shaping the trade-off between current and future reproduction. 5Lifetime reproductive success of females, measured as the total number of locally recruiting offspring over the 4 experimental years, was reduced significantly by ectoparasites. The negative effect of parasites arose by a reduction of the number of fledglings per breeding attempt rather than by a reduction of the number of breeding attempts. [source]

    General guidelines for invasive plant management based on comparative demography of invasive and native plant populations

    Satu Ramula
    Summary 1General guidelines for invasive plant management are currently lacking. Population declines may be achieved by focusing control on demographic processes (survival, growth, fecundity) with the greatest impact on population growth rate. However, we often have little demographic information on populations in the early stages of an invasion when control can be most effective. Here we determine whether synthesis of existing demographic data on invasive and native plant populations can address this knowledge problem. 2We compared population dynamics between invasive and native species using published matrix population models for 21 invasive and 179 native plant species. We examined whether the population growth rate responsiveness to survival, growth and fecundity perturbations varied between invasive and native species, and determined which demographic processes of invaders to target for reductions in population growth rate. 3Invaders had higher population growth rates (,) than natives, resulting in differences in demographic processes. Perturbations of growth and fecundity transitions (elasticities) were more important for population growth of invaders, whereas perturbations of survival had greater importance for population growth of natives. 4For both invasive and native species, elasticities of , to survival increased with life span and decreased with ,; while elasticities to growth and fecundity decreased with life span and increased with ,. 5For long-lived invaders, simulated reductions in either survival, growth or fecundity transitions were generally insufficient to produce population declines, whereas multiple reductions in either survival + growth or survival + fecundity were more effective. For short-lived invaders, simulated reductions in growth or fecundity and all pairwise multiple reductions produced population declines. 6Synthesis and applications. Life history and population growth rate of invasive species are important in the selection of control targets. For rapidly growing populations of short-lived invaders, growth and fecundity transitions should be prioritized as control targets over survival transitions. For long-lived invaders, simultaneous reductions in more than one demographic process, preferably survival and growth, are usually required to ensure population decline. These general guidelines can be applied to rapidly growing new plant invasions and at the invasion front where detailed demographic data on invasive species are lacking. [source]

    Age-based life history parameters and status assessments of by-catch species (Lethrinus borbonicus, Lethrinus microdon, Pomacanthus maculosus and Scolopsis taeniatus) in the southern Arabian Gulf

    E. Grandcourt
    Summary Life history and demographic parameters for Lethrinus borbonicus, Lethrinus microdon, Pomacanthus maculosus and Scolopsis taeniatus in the southern Arabian Gulf were estimated using a combination of size frequency, biological and size-at-age data. Defined structural increments consisting of alternating translucent and opaque bands in transverse sections of sagittal otoliths were validated as annuli. The maximum age estimates ranged from 5 years for Scolopsis taeniatus to 36 years for Pomacanthus maculosus. The size-at-age relationships were highly asymptotic in form with the majority of growth being achieved early in life. There were significant differences in the growth characteristics between sexes for Pomacanthus maculosus, with males approaching a larger asymptotic size at a faster rate than females. With the exception of Scolopsis taeniatus, the mean age at which fish became vulnerable to capture was lower than the mean age at first sexual maturity. The stocks of L. microdon, P. maculosus and S. taeniatus were exploited within sustainable limits, conversely, L. borbonicus was found to be overexploited and recruitment overfishing may have occurred as the relative spawner biomass per recruit was below 30% of the unexploited state. [source]

    Life history, ecology and longevity in bats

    AGING CELL, Issue 2 2002
    Gerald S. Wilkinson
    Summary The evolutionary theory of aging predicts that life span should decrease in response to the amount of mortality caused by extrinsic sources. Using this prediction, we selected six life history and ecological factors to use in a comparative analysis of longevity among 64 bat species. On average, the maximum recorded life span of a bat is 3.5 times greater than a non-flying placental mammal of similar size. Records of individuals surviving more than 30 years in the wild now exist for five species. Univariate and multivariate analyses of species data, as well as of phylogenetically independent contrasts obtained using a supertree of Chiroptera, reveal that bat life span significantly increases with hibernation, body mass and occasional cave use, but decreases with reproductive rate and is not influenced by diet, colony size or the source of the record. These results are largely consistent with extrinsic mortality risk acting as a determinant of bat longevity. Nevertheless, the strong association between life span and both reproductive rate and hibernation also suggests that bat longevity is strongly influenced by seasonal allocation of non-renewable resources to reproduction. We speculate that hibernation may provide a natural example of caloric restriction, which is known to increase longevity in other mammals. [source]

    Life history and ecology of seahorses: implications for conservation and management

    S. J. Foster
    We present the first synthesis of the life history and ecology of seahorses, compare relationships for seahorses with other marine teleosts and identify research needs. Seahorses occurred primarily amidst temperate seagrasses and tropical coral reefs. Population densities were generally low, ranging from 0 to 0·51 individuals m,2, but reached 10 m,2 in some patches. Inferred life spans ranged from 1 to 5 years. Seahorses consumed live prey and possibly changed diet as they grew. Growth rates are poorly investigated to date. Reproduction and mating systems are the best-studied aspects of seahorse ecology. The relationship between size at first maturity and maximum size in seahorses conformed to that for other marine teleosts. All seahorse species were monogamous within a cycle, but some were polygamous across cycles. Direct transfer of clutches to the brood pouch of the male fish made it difficult to measure clutch size in live seahorses. After brooding, males released from c. 5 to 2000 young, depending on species and adult size. Newborn young measured from 2 to 20 mm in length, which was a narrower size range than the 17-fold difference that occurred in adult size. Newborn body size had no relationship to adult size. Both eggs and young were larger than expected among marine teleosts, even when considering only those with parental care, but brood size at release was lower than expected, perhaps because the young were more developed. The size of adults, eggs and young increased with increasing latitude, although brood size did not. Considerable research is needed to advance seahorse conservation and management, including (a) fisheries-dependent and fisheries-independent abundance estimates, (b) age- or stage-based natural and fishing mortalities, (c) growth rates and age at first maturity, and (d) intrinsic rates of increase and age- or size-specific reproductive output. Current data confirm that seahorses are likely to be vulnerable to high levels of exploitation. [source]

    135 Life History and Ecology of Trentepohliaceae (Chlorophyta) in the West of Ireland

    F. Rindi
    Species of subaerial green algae of the family Trentepohliaceae are common in tropical and temperate regions. Despite nearly two centuries of investigations, several important aspects of their biology (such as life history and taxonomic relationships of some species) are still poorly understood. In western Ireland, the abundance of Trentepohliaceae is a peculiar feature of the subaerial algal vegetation. Six species are present (Phycopeltis arundinacea, Printzina lagenifera, Trentepohlia abietina, T. aurea, T. iolithus and T. umbrina). Life history and phenology of these were examined by extensive field and culture studies. In contrast to most other subaerial algae, the Trentepohliaceae show a generally strict substratum-specificity in western Ireland. T. iolithus, in particular, is remarkable for its occurrence on concrete walls, where it may produce extensive dark-red growths. Our observations suggest that general statements about the life history of Trentepohlia should be reconsidered critically. There is no evidence that in Irish populations a regular alternation of isomorphic gametophytes and sporophytes takes place; biflagellate swarmers (usually considered gametes) behave as asexual spores and reproduce the same morphological phase. No fusion of gametes was observed and a detailed examination of the literature concerning the genus shows that this phenomenon is extremely rare. A combination of studies based on different types of data (molecular data, examination of very large numbers of field samples, chromosome numbers, culture studies) is considered fundamental to any definitive clarification of the taxonomy and life history of Trentepohlia. [source]

    Life history of amphibians in the seasonal tropics: habitat, community and population ecology of a caecilian (genus Ichthyophis)

    JOURNAL OF ZOOLOGY, Issue 3 2005
    Alexander Kupfer
    Abstract Fundamental information on the ecology of the limbless tropical caecilians is needed for a well-founded conservation assessment. Here, essential life-history characters are presented for the oviparous caecilian Ichthyophis cf. kohtaoensis from a field site in South-east Asia (Mekong valley, north-eastern Thailand). Ichthyophis cf. kohtaoensis was found in a range of terrestrial macrohabitats including open scrubs, gallery forests and open secondary dipterocarp forests. In the dry season, caecilians were found mainly in soil but in the rainy season they were also detected in epigeic microhabitats (leaf litter or rotten vegetation). Ichthyophis cf. kohtaoensis were recorded in low densities (median 0.08 individuals/m2) and they share their habitat with a range of other terrestrial amphibians and reptiles. The population structure of I. cf. kohtaoensis varied seasonally. Records of late metamorphs were restricted to the cold dry season and occasionally to the onset of the rainy season. Females with clutches were only found in the rainy season. A life-history scenario of I. cf. kohtaoensis in north-eastern Thailand was set up. Reproduction and larval development is related to the rainy season. Mating and oviposition may start at the onset of the monsoon. Larvae hatch at the peak until the end of the rainy season and metamorphose until the end of the dry season. In the light of amphibian decline, this study may encourage further baseline work on the ecology of other caecilian species. [source]

    Life history determines biogeographical patterns of soil bacterial communities over multiple spatial scales

    MOLECULAR ECOLOGY, Issue 19 2010
    Abstract The extent to which the distribution of soil bacteria is controlled by local environment vs. spatial factors (e.g. dispersal, colonization limitation, evolutionary events) is poorly understood and widely debated. Our understanding of biogeographic controls in microbial communities is likely hampered by the enormous environmental variability encountered across spatial scales and the broad diversity of microbial life histories. Here, we constrained environmental factors (soil chemistry, climate, above-ground plant community) to investigate the specific influence of space, by fitting all other variables first, on bacterial communities in soils over distances from m to 102 km. We found strong evidence for a spatial component to bacterial community structure that varies with scale and organism life history (dispersal and survival ability). Geographic distance had no influence over community structure for organisms known to have survival stages, but the converse was true for organisms thought to be less hardy. Community function (substrate utilization) was also shown to be highly correlated with community structure, but not to abiotic factors, suggesting nonstochastic determinants of community structure are important Our results support the view that bacterial soil communities are constrained by both edaphic factors and geographic distance and further show that the relative importance of such constraints depends critically on the taxonomic resolution used to evaluate spatio-temporal patterns of microbial diversity, as well as life history of the groups being investigated, much as is the case for macro-organisms. [source]

    Habits of the heart: Life history and the developmental neuroendocrinology of emotion

    Carol M. Worthman
    The centrality of emotion in cognition and social intelligence as well as its impact on health has intensified investigation into the causes and consequences of individual variation in emotion regulation. Central processing of experience directly informs regulation of endocrine axes, essentially forming a neuro-endocrine continuum integrating information intake, processing, and physiological and behavioral response. Two major elements of life history,resource allocation and niche partitioning,are served by linking cognitive-affective with physiologic and behavioral processes. Scarce cognitive resources (attention, memory, and time) are allocated under guidance from affective co-processing. Affective-cognitive processing, in turn, regulates physiologic activity through neuro-endocrine outflow and thereby orchestrates energetic resource allocation and trade-offs, both acutely and through time. Reciprocally, peripheral activity (e.g., immunologic, metabolic, or energetic markers) influences affective-cognitive processing. By guiding attention, memory, and behavior, affective-cognitive processing also informs individual stances toward, patterns of activity in, and relationships with the world. As such, it mediates processes of niche partitioning that adaptively exploit social and material resources. Developmental behavioral neurobiology has identified multiple factors that influence the ontogeny of emotion regulation to form affective and behavioral styles. Evidence is reviewed documenting roles for genetic, epigenetic, and experiential factors in the development of emotion regulation, social cognition, and behavior with important implications for understanding mechanisms that underlie life history construction and the sources of differential health. Overall, this dynamic arena for research promises to link the biological bases of life history theory with the psychobehavioral phenomena that figure so centrally in quotidian experience and adaptation, particularly, for humans. Am. J. Hum. Biol. 2009. © 2009 Wiley-Liss, Inc. [source]

    Proceedings of the 20th Annual Conference of the Japanese Association for Adolescent Psychotherapy, 16 November 2002, Tokyo, Japan

    Article first published online: 28 AUG 200
    Inpatient treatment of obsessive,compulsive disorder in a child and adolescent psychiatry ward M. USAMI National Center of Neurology and Psychiatry, Kohnodai Hospital, Chiba, Japan This is a case report of a 13-year-old-boy (2nd grade in junior high school). His father had poor communication; his mother was a very fragile woman. The boy had been overprotected by his parents, as long as he responded to their expectations. He did not have any other siblings. He played well with his friends since he was young, and did not have problems until the 1st term (from April to July) of 1st grade in junior high school. However, in September he started to have difficulties going well with his friends, and going to school. He spent most of his time in his room, and began to repeat checking and hand-washing frequently. Even at midnight, he forced his mother to touch the shutter from outside of the house for many times. He also ritually repeated to touch his mother's body, after he licked his hands, for over an hour. He became violent, when his parents tried to stop him. In April, year X, his parents visited our hospital for the first time. From then, his mother could not tolerate her son's coerciveness any longer. His father explained to the boy that ,your mother has been hospitalized', and she started to live in the next room to the boy's without making any noise. After 3 months he noticed that his mother was not hospitalized, and he got very excited. He was admitted to our hospital with his family and relatives, in October, year X. At the initial stage of hospitalization he showed distrust and doubt towards the therapist and hospital. He had little communication with other boys and did not express his feelings. Therefore, there was a period of time where he seemed to wonder whether he could trust the treatment staff or not. During his interviews with his therapist he repeated only ,I'm okay' and did not show much emotional communication. For the boy, exposing himself was equivalent to showing his vulnerability and incompleteness. Therefore, the therapist considered that he was trying to denying his feelings to avoid this. The therapist set goals for considering his own feelings positively and expressing them appropriately. Also, the therapist carried out behavioral restrictions towards him. He hardly had any emotional communication with the staff, and his peer relationship in the ward was superficial. Therefore, he gradually had difficulty spending his time at the end of December On the following day in which he and the therapist decided to return to his house for the first time, he went out of the ward a few days before without permission. From thereon it was possible for him to share feelings such as hostility and aggression, dependence and kindness with the therapist. The therapist changed his role from an invasive one to a more protective one. Then, his unsociability gradually faded. He also developed good peer relationships with other boys in the ward and began to express himself feeling appropriately. He was also able to establish appropriate relations with his parents at home, and friends of his neighborhood began to have normal peer relationships again. During childhood and adolescence, boys with obsessive,compulsive disorder are known to have features such as poor insight and often involving their mothers. We would like to present this case, through our understanding of dynamic psychiatry throughout his hospitalization, and also on the other therapies that were performed. Psychotherapy with a graduate student that discontinued after only three sessions: Was it enough for this client? N. KATSUKI Sophia University, Tokyo, Japan Introduction: Before and after the psychotherapy, SWT was administrated in this case. Comparing these two drawings, the therapist was provided with some ideas of what kind of internal change had taken place inside this client. Referring to the changes observed, we would like to review the purposes and the ways of the psychotherapy, as well as the adequacy of the limited number of the sessions (vis-a-vis result attained.) Also we will discuss later if any other effective ways could be available within the capacities of the consulting system/the clinic in the university. Case: Ms. S Age 24 years. Problems/appeal: (i) awkwardness in the relationship with the laboratory colleagues; (ii) symptoms of sweating, vomiting and quivering; and (iii) anxiety regarding continuing study and job hunting. Diagnosis: > c/o PTSD. Psychotherapeutic setting: At the therapy room in the clinic, placed at the university, 50 min-session; once a week; paralleled with the medical treatment. Process: (1) Since she was expelled from the study team in the previous year, it has become extremely difficult for her to attend the laboratory (lab) due to the aforementioned symptoms. She had a feeling of being neglected by the others. When the therapist suggested that she compose her mental confusions in the past by attending the therapy room, she seemed to be looking forward to it, although she said that she could remember only a few. (2) She reported that she overdosed on sedatives, as she could not stop irritating. She was getting tough with her family, also she slashed the mattress of her bed with a knife for many times. She complained that people neither understood nor appreciated her properly. and she said that she wanted revenge on the leader of the lab by punishing him one way or other. (3) Looking back the previous session, she said ,I had been mentally mixed up at that time, but I feel that now I can handle myself, as I stopped the medication after consulting the psychiatrist. According to what she said, when she disclosed the occurrences in the lab to her mother, she felt to be understood properly by her mother and felt so relieved. and she also reported that she had been sewing up the mattress which she slashed before, without any reason. She added, " although I don't even know what it means, I feel that this work is so meaningful to me, somehow". Finally, she told that she had already made her mind to cope with the situation by herself from now on, although it might result in a flinch from the real solution. Situations being the above, the session was closed. Swt: By the remarkable changes observed between the two drawings, the meanings of this psychotherapy and its closure to the client would be contemplated. Question of how school counselors should deal with separation attendant on students' graduation: On a case in which the separation was not worked through C. ASAHARA Sophia University, Tokyo, Japan Although time limited relationship is one of the important characteristics in school counseling, the question of separation attendant on it has not been much discussed based on specific cases. This study focuses on the question of separation through looking at a particular case, in which the separation was not worked through, and halfway relationship continued even after the student's graduation and the counselor's resignation. I was a part time school counselor at a junior high school in Tokyo. The client was a 14-year-old female student, who could not go to her classroom, and spent a few hours in a sick bay when she came to school. She was in the final grade and there was only half a year left before graduation when we first met, and we started to see each other within a very loose structure. As her personality was hyper-vigilant and defensive, it took almost 2 months before I could feel that she was nearer. Her graduation was the first occasion of separation. On that occasion, I found that there had been a discrepancy between our expectations; while I took it for granted that our relationship would end with the graduation, she expected to see me even after she graduated, and she actually came up to see me once in a while during the next year. A year later, we faced another occasion of separation, that was my resignation. Although I worried about her, all I have done for her was to hand a leaflet of a counseling office, where I work as a part time counselor. Again I could not refer to her feelings or show any concrete directions such as making a fixed arrangement. After an occasional correspondence for the next 10 months (about 2 years after her graduation), she contacted me at the counseling office asking for a constant counseling. Why could I not deal with both occasions? and how did that affect the client thereafter? There were two occasions of separation. At the time of the client's graduation, I seemed to be enmeshed in the way of separation that is peculiar to the school setting. In general in therapeutic relationship, mourning work between counselor and client is regarded as being quite important. At school, however, separation attendant on graduation is usually taken for granted and mourning work for any personal relationship tends to be neglected. Graduation ceremony is a big event but it is not about mourning over one's personal relationships but separation from school. That may be why I did not appreciate how the client counted on our relationship. At the time of my resignation I was too worried about working through a change from very loose structure which is peculiar to the school setting to a usual therapeutic structure (fees are charged, and time, place are fixed). That is why I did nothing but give her a leaflet. In this way, we never talked about her complex feelings such as sadness or loneliness, which she was supposed to experience on separation. Looking at the aforementioned process from the client's viewpoint, it can be easily imagined that she could not accept the fact of separation just because she graduated. and later, she was forced to be in double-bind situation, in which she was accepted superficially (handed a leaflet), while no concrete possibility was proposed concerning our relationship (she could never see me unless she tries to contact me.) As a result, she was left alone and at a loss whether she could count on me or not. The halfway situation or her suspense was reflected in her letter, in which she appeared to be just chatting at first sight, but between the lines there was something more implying her sufferings. Above discussion suggests that in some case, we should not neglect the mourning work even in a school setting. To whom or how it is done is the next theme we should explore and discuss in the future. For now, we should at least be conscious about the question of separation in school setting. Study of the process of psychotherapy with intervals for months M. TERASHIMA Bunkyo Gakuin University, Tokyo, Japan This is a report on the process of psychotherapy of an adolescent girl who showed manic and depressive state. At the time of a depressed state, she could not go to a college and withdrew into home, and the severe regressive situation was shown. Her therapy began at the age of 20 and she wanted to know what her problem was. The process of treatment went on for 4 years but she stopped coming to sessions for several months because of failure of the therapist. She repeated the same thing twice. After going through these intervals the client began to remember and started to talk about her childhood , suffering abusive force from her father, with vivid impressions. They once were hard for her to accept, but she began to establish the consistent figure of herself from past to present. In this case, it could be thought that the intervals of the sessions had a certain role, with which the client controlled the structure of treatment, instead of an attack against the therapist. Her object relation, which is going to control an object offensively, was reflected in these phenomena. That is, it can be said that the ambivalence about dependency , difficult to depend but desirous of the object , was expressed. Discontinuation of the sessions was the product of the compromise formation brought about the ambivalence of the client, and while continuing to receive this ambivalence in the treatment, the client started to realize discontinuance of her memories and then advanced integration of her self-image. For the young client with conflict to dependence such as her, an interval does not destroy the process of treatment but in some cases it could be considered as a therapeutic element. In the intervals the client could assimilate the matter by herself, that acquired by the sessions. Psychotherapy for a schizoid woman who presented eccentric speech and behaviour M. OGASAWARA Osaka University Graduate School of Medicine, Osaka, Japan Case presentation: A case of a 27-year-old woman at the beginning of therapy. Life history: She had been having a wish for death since she was in kindergarten and she had been feeling strong resistance to do the same as others after school attendance. She had a history of ablutomania from the age of 10,15, but the symptom disappeared naturally. and she said that she had been eliminated from groups that she tried to enter. After graduating a junior college, she changed jobs several times without getting a full-time position. Present history: Scolded by her boy friend for her coming home too late one day, she showed confusion such as excitement, self-injury or terror. She consulted a psychiatrist in a certain general hospital, but she presented there eccentric behaviours such as tense facial expression, stiffness of her whole body, or involuntary movement of limbs. and because she felt on bad terms with the psychiatrist and she had come to cause convulsion attacks in the examination room, she was introduced to our hospital. Every session of this psychotherapy was held once a week and for approximately 60 min at a time. Treatment process: She sometimes presented various eccentric attitudes, for example overturning to the floor with screaming (1), going down on her knees when entrance at the door (5), entering with a knife in her mouth and hitting the wall suddenly (7), stiffening herself just outside the door without entering the examination room (9), taking out a knife abruptly and putting it on her neck (40), exclaiming with convulsion responding to every talk from the therapist (41), or stiffening her face and biting herself in the right forearm suddenly (52). She also repeated self-injuries or convulsion attacks outside of the examination room in the early period of the therapy. Throughout the therapy she showed hypersensitivity for interpersonal relations, anxiety about dependence, terror for self-assertion, and avoidance for confrontation to her emotional problems. Two years and 6 months have passed since the beginning of this therapy. She ceased self-injury approximately 1 year and 6 months before and her sense of obscure terror has been gradually reduced to some extent. Discussion: Her non-verbal wariness and aggression to the therapist made the sessions full of tension and the therapist felt a sense of heaviness every time. In contrast, she could not express aggression verbally to the therapist, and when the therapist tried to identify her aggression she denied it. Her anxiety, that she will be thoroughly counterattacked to self-disintegration if she shows aggression to other persons, seems to be so immeasurably strong that she is compelled to deny her own aggression. Interpretations and confrontations by the therapist make her protective, and occasionally she shows stronger resistance in the shape of denial of her problems or conversion symptoms (astasia, aphonia, or involuntary movements) but she never expresses verbal aggression to the therapist. and the therapist feels much difficulty to share sympathy with her, and she expresses distrust against sympathetic approach of the therapist. However, her obvious disturbance that she expresses when she feels the therapist is not sympathetic shows her desire for sympathy. Thus, because she has both strong distrust and desire for sympathy, she is in a porcupine dilemma, which is characteristic of schizoid patients as to whether to lengthen or to shorten the distance between herself and the therapist. This attitude seems to have been derived from experience she might have had during her babyhood and childhood that she felt terror to be counterattacked and deserted when she showed irritation to her mother. In fact, existence of severe problems of the relationship between herself and her mother in her babyhood and childhood can be guessed from her statement. Although she has been repeating experiences to be excluded from other people, she shows no attitude to construct interpersonal relationship actively. On the contrary, by regarding herself to be a victim or devaluating other persons she externalizes responsibility that she herself should assume essentially. The reason must be that her disintegration anxiety is evoked if she recognizes that she herself has problems; that is, that negative things exist inside of her. Therefore, she seems to be inhibited to get depressive position and obliged to remain mainly in a paranoid,schizoid position. As for the pathological level, she seems to have borderline personality organization because of frequent use of mechanisms to externalize fantastically her inner responsibility. For her high ability to avoid confronting her emotional problems making the most of her verbal ability, every intervention of the therapist is invalidated. So, it seems very difficult for her to recognize her own problems through verbal interpretations or confrontation by the therapist, for the present. In general, it is impossible to confront self problems without containing negative emotions inside of the self, but her ability seemed to be insufficient. So, to point out her problems is considered to be very likely to result in her confusion caused by persecution anxiety. Although the therapy may attain the stage on which verbal interpretation and confrontation work better some day, the therapist is compelled to aim at promoting her ability to hold negative emotion inside of herself for the time being. For the purpose, the therapist is required to endure the situation in which she brings emotion that makes the therapist feel negative counter-transference and her process to experience that the therapeutic relation itself would not collapse by holding negative emotion. On supportive psychotherapy with a male adolescent Y. TERASHIMA Kitasato University Health Care Center, Kanagawa, Japan Adolescent cases sometimes show dramatic improvements as a consequence of psychotherapy. The author describes how psychotherapy can support an adolescent and how theraputic achievements can be made. Two and a half years of treatment sessions with a male adolescent patient are presented. The patient was a 19-year-old man, living with his family. He had 5 years of experience living abroad with his family and he was a preparatory school student when he came to a mental clinic for help. He was suffering from not being able to sleep well, from difficulties concerning keeping his attention on one thing, and from fear of going to distant places. He could barely leave his room, and imagined the consequence of overdosing or jumping out of a window. He claimed that his life was doomed because his family moved from a town that was familiar to him. At the first phase of psychotherapy that lasted for approximately 1 year, the patient seldom responded to the therapist. The patient was basically silent. He told the therapist that the town he lives in now feels cold or that he wants to become a writer. However, these comments were made without any kind of explanation and the therapist felt it very difficult to understand what the patient was trying to say. The sessions continued on a regular basis. However, the therapist felt very useless and fatigued. Problems with the patient and his family were also present at this phase of psychotherapy. He felt unpleasant at home and felt it was useless to expect anything from his parents. These feelings were naturally transferred to the therapist and were interpreted. However, interpretation seemed to make no changes in the forms of the patient's transference. The second phase of psychotherapy began suddenly. The patient kept saying that he did not know what to talk about. However, after a brief comment made by the therapist on the author of the book he was reading, the patient told the therapist that it was unexpected that the therapist knew anything of his favorite writer. After this almost first interaction between the patient and the therapist, the patient started to show dramatic changes. The patient started to bring his favorite rock CDs to sessions where they were played and the patient and the therapist both made comments on how they felt about the music. He also started asking questions concerning the therapist. It seemed that the patient finally started to want to know the therapist. He started communicating. The patient was sometimes silent but that did not last long. The therapist no longer felt so useless and emotional interaction, which never took place in the first phase, now became dominant. The third phase happened rapidly and lasted for approximately 10 months. Conversations on music, art, literature and movies were made possible and the therapist seldom felt difficulties on following the patient's line of thought. He started to go to schools and it was difficult at first but he started adjusting to the environment of his new part-time jobs. By the end of the school year, he was qualified for the entrance to a prestigious university. The patient's problems had vanished except for some sleeping difficulties, and he did not wish to continue the psychotherapy sessions. The therapist's departure from the clinic added to this and the therapy was terminated. The patient at first reminded the therapist of severe psychological disturbances but the patient showed remarkable progress. Three points can be considered to have played important roles in the therapy presented. The first and the most important is the interpretation by behavior. The patient showed strong parental transference to the therapist and this led the therapist to feel useless and to feel fatigue. Content analysis and here-and-now analysis seemed to have played only a small part in the therapy. However, the therapist tried to keep in contact with the patient, although not so elegant, but tried to show that the therapist may not be useless. This was done by maintaining the framework of the therapy and by consulting the parents when it was considered necessary. Second point is the role that the therapist intentionally took as a model or target of introjection. With the help of behavioral interpretation that showed the therapist and others that it may not be useless, the patient started to introject what seemed to be useful to his well being. It can be considered that this role took some part in the patient going out and to adjust to the new environment. Last, fortune of mach must be considered. The patient and the therapist had much in common. It was very fortunate that the therapist knew anything about the patient's favorite writer. The therapist had some experience abroad when he was young. Although it is a matter of luck that the two had things in common, it can be said that the congeniality between the patient and the therapist played an important role in the successful termination of the therapy. From the physical complaint to the verbal appeal of A's recovery process to regain her self-confidence C. ITOKAWA and S. KAZUKAWA Toyama Mental Health Center, Toyama, Japan This is one of the cases at Toyama Mental Health Center about a client here, we will henceforth refer to her simply as ,A'. A was a second grade high school student. We worked with her until her high school graduation using our center's full functions; counseling, medical examination and the course for autogenic training (AT). She started her counseling by telling us that the reason for her frequent absences from school began because of stomach pains when she was under a lot of stress for 2 years of junior high school, from 2nd grade to 3rd grade. Due to a lack of self confidence and a constant fear of the people around her, she was unable to use the transportation. She would spend a large amount of time at the school infirmary because she suffered from self-diagnosed hypochondriac symptoms such as nausea, diarrhea and a palpitation. She continued that she might not be able to have the self-confidence to sit still to consult me on her feelings in one of our sessions. A therapist advised her to take the psychiatric examination and the use of AT and she actually saw the medical doctor. In counseling (sessions), she eventually started to talk about the abuse that started just after her entering of junior high school; she approached the school nurse but was unable to tell her own parents because she did not trust them. In doing so, she lost the rest of her confidence, affecting the way she looked at herself and thought of how others did. At school she behaved cheerfully and teachers often accused her of idleness as they regarded this girl's absences along with her brightly dyed hair and heavy make-up as her negligent laziness. I, as her therapist, contacted some of the school's staff and let them know of her situation in detail. As the scolding from the teachers decreased, we recognized the improvement of her situation. In order to recover from the missed academic exposure due to her long absence, she started to study by herself. In a couple of months her physical condition improved gradually, saying ,These days I have been doing well by myself, haven't I?' and one year later, her improved mental condition enabled her to go up to Tokyo for a concert and furthermore even to enjoy a short part-time job. She continued the session and the medical examination dually (in tangent) including the consultation about disbelief to the teachers, grade promotion, relationships between friends and physical conditions. Her story concentrated on the fact that she had not grown up with sufficiently warm and compassionate treatment and she could not gain any mental refuge in neither her family nor her school, or even her friends. Her prospects for the future had changed from the short-ranged one with no difficulty to the ambitious challenge: she aimed to try for her favorite major and hoped to go out of her prefecture. But she almost had to give up her own plan because the school forced her to change her course as they recommended. (because of the school's opposition with her own choice). So without the trust of the teachers combined with her low self-esteem she almost gave up her hopes and with them her forward momentum. In this situation as the therapist, I showed her great compassion and discussed the anger towards the school authorities, while encouraging this girl by persuading her that she should have enough self-confidence by herself. Through such sessions, she was sure that if she continued studying to improve her own academic ability by herself she could recognize the true meaning of striving forward. and eventually, she received her parents' support who had seemed to be indifferent to her. At last she could pass the university's entrance exams for the school that she had yearned to attend. That girl ,A' visited our center 1 month later to show us her vivid face. I saw a bright smile on her face. It was shining so brightly. [source]

    "Life history space": A multivariate analysis of life history variation in extant and extinct Malagasy lemurs

    Kierstin K. Catlett
    Abstract Studies of primate life history variation are constrained by the fact that all large-bodied extant primates are haplorhines. However, large-bodied strepsirrhines recently existed. If we can extract life history information from their skeletons, these species can contribute to our understanding of primate life history variation. This is particularly important in light of new critiques of the classic "fast-slow continuum" as a descriptor of variation in life history profiles across mammals in general. We use established dental histological methods to estimate gestation length and age at weaning for five extinct lemur species. On the basis of these estimates, we reconstruct minimum interbirth intervals and maximum reproductive rates. We utilize principal components analysis to create a multivariate "life history space" that captures the relationships among reproductive parameters and brain and body size in extinct and extant lemurs. Our data show that, whereas large-bodied extinct lemurs can be described as "slow" in some fashion, they also varied greatly in their life history profiles. Those with relatively large brains also weaned their offspring late and had long interbirth intervals. These were not the largest of extinct lemurs. Thus, we distinguish size-related life history variation from variation that linked more strongly to ecological factors. Because all lemur species larger than 10 kg, regardless of life history profile, succumbed to extinction after humans arrived in Madagascar, we argue that large body size increased the probability of extinction independently of reproductive rate. We also provide some evidence that, among lemurs, brain size predicts reproductive rate better than body size. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc. [source]

    Synchrony between growth and reproductive patterns in human females: Early investment in growth among Pumé foragers

    Karen L. Kramer
    Abstract Life history is an important framework for understanding many aspects of ontogeny and reproduction relative to fitness outcomes. Because growth is a key influence on the timing of reproductive maturity and age at first birth is a critical demographic variable predicting lifetime fertility, it raises questions about the synchrony of growth and reproductive strategies. Among the Pumé, a group of South American foragers, young women give birth to their first child on average at age 15.5. Previous research showed that this early age at first birth maximizes surviving fertility under conditions of high infant mortality. In this study we evaluate Pumé growth data to test the expectation that if early reproduction is advantageous, then girls should have a developmental trajectory that best prepares them for young childbearing. Analyses show that comparatively Pumé girls invest in skeletal growth early, enter puberty having achieved a greater proportion of adult body size and grow at low velocities during adolescence. For early reproducers growing up in a food-limited environment, a precocious investment in growth is advantageous because juveniles have no chance of pregnancy and it occurs before the onset of the competing metabolic demands of final reproductive maturation and childbearing. Documenting growth patterns under preindustrial energetic and demographic conditions expands the range of developmental variation not otherwise captured by normative growth standards and contributes to research on human phenotypic plasticity in diverse environments. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source]