Proceedings of the Royal Society of London. Series B. Biological Sciences最新文献_第4页

Going nuclear: gene family evolution and vertebrate phylogeny reconciled 走向核:基因家族进化与脊椎动物系统发育的调和

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2074

J. Cotton, R. Page

引用次数: 89

Severe inbreeding depression in collared flycatchers (Ficedula albicollis) 有领捕蝇(Ficedula albicollis)的严重近亲繁殖抑制

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2049

L. Kruuk, B. Sheldon, J. Merilä

{"title":"Severe inbreeding depression in collared flycatchers (Ficedula albicollis)","authors":"L. Kruuk, B. Sheldon, J. Merilä","doi":"10.1098/rspb.2002.2049","DOIUrl":"https://doi.org/10.1098/rspb.2002.2049","url":null,"abstract":"The causes and magnitude of inbreeding depression are of considerable importance for a wide range of issues in evolutionary and conservation biology, but we have only a limited understanding of inbreeding depression in natural populations. Here, we present a study of inbreeding in a large wild population of collared flycatchers (Ficedula albicollis). Inbreeding was rare, to the extent that we detected only 1.04%of 2139 matings over 18 years that resulted in offspring with a non–zero inbreeding coefficient, f > 0. When it did occur, inbreeding caused a significant reduction in the egg–hatching rate, in fledgling skeletal size and in post–fledging juvenile survival, with the number of offspring being recruited to the breeding population from a nest of f = 0.25 being reduced by 94% relative to a non–inbred nest. A maximum–likelihood estimate of the number of lethal equivalents per gamete was very high at B = 7.47, indicating a substantial genetic load in this population. There was also a non–significant tendency for inbreeding depression to increase with the strength of selection on a trait. The probability of mating between close relatives f = 0.25) increased throughout the breeding season, possibly reflecting increased costs of inbreeding avoidance. Our results illustrate how severe inbreeding depression and considerable genetic load may exist in natural populations, but detecting them may require extensive long–term datasets.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"72 1","pages":"1581 - 1589"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91052065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 196

Host–pathogen interactions in a varying environment: temperature, behavioural fever and fitness 宿主-病原体在不同环境中的相互作用:温度、行为性发热和适应性

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2067

S. Elliot, S. Blanford, M. Thomas

{"title":"Host–pathogen interactions in a varying environment: temperature, behavioural fever and fitness","authors":"S. Elliot, S. Blanford, M. Thomas","doi":"10.1098/rspb.2002.2067","DOIUrl":"https://doi.org/10.1098/rspb.2002.2067","url":null,"abstract":"We demonstrate how variable temperatures, mediated by host thermoregulation and behavioural fever, critically affect the interaction between a host (the desert locust, Schistocerca gregaria) and a pathogen (the fungus Metarhizium anisopliae var. acridum). By means of behavioural thermoregulation, infected locusts can raise their body temperatures to fever levels. The adaptive value of this behaviour was examined using three thermal regimes wherein maximum body temperatures achievable were: (i) below, or (ii) at normally preferred temperatures, or were (iii) unrestricted, allowing heightened fever temperatures. All infected locusts ultimately succumbed to disease, with median survival times of 8, 15 and 21 days post–infection, respectively. Crucially, only those locusts able to fever produced viable offspring. This represents, to our knowledge, the first demonstration of the adaptive value of behavioural fever following infection with a naturally occurring pathogen. By contrast, although normal host thermoregulation moderately reduced pathogen reproduction (by 35%), there was no additional negative effect of fever, resulting in an asymmetry in the fitness consequences of fever for the host and the pathogen. The dependency of the host–pathogen interaction upon external abiotic conditions has implications for how virulence and resistance are treated both theoretically and in the management of pests and diseases.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"180 1","pages":"1599 - 1607"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91507042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 221

Analysing noisy time–series: describing regional variation in the cyclic dynamics of red grouse 噪声时间序列分析:描述红松鸡循环动态的区域变化

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2053

D. Haydon, D. Shaw, I. Cattadori, P. Hudson, S. Thirgood

{"title":"Analysing noisy time–series: describing regional variation in the cyclic dynamics of red grouse","authors":"D. Haydon, D. Shaw, I. Cattadori, P. Hudson, S. Thirgood","doi":"10.1098/rspb.2002.2053","DOIUrl":"https://doi.org/10.1098/rspb.2002.2053","url":null,"abstract":"We develop a method for describing the periodicity of noisy ‘quasi–cyclic’ time–series based on integrals of their power spectra corresponding to different frequency intervals that we use to classify time–series as ‘strongly cycli’,‘weakly cycli’ or‘non–cycli’. We apply this analysis to over 300 time–series of shooting records of red grouse from 289 moors located in 20 regions of the UK. Time–series from 63 of these populations were not distinguishable from white noise, but significant evidence of cyclic behaviour in the 2–15 year range was detected in time–series from 183 other populations. Time–series from the remaining 43 populations, though distinguishable from white noise, did not exhibit consistently recognizable cyclic behaviour in the same period range. Cyclic populations exhibit an average periodicity of 8.3 years, but only 20% of these populations cycle with a period of four to six years. Geographically, grouse populations are remarkable more for their dynamic heterogeneity than for any observable regularity. The relationship between the location of populations and their dynamical behaviour is weak. The prevalence of cyclic time–series within a region did not significantly differ from the overall average value. Moor region explained 22% of the variation in periodicity, differing from the overall mean in three regions. Average periodicity increases significantly from 6.8 to 8.9 years from the most southerly to most northerly populations. However, latitude explains only 5.3% of the variation in periodicity of the cycles.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"2 1","pages":"1609 - 1617"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87942737","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 55

Positive fitness consequences of interspecific interaction with a potential competitor 与潜在竞争者的种间相互作用的正适合度结果

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2065

Jukka T. Forsman, Janne-Tuomas Seppänen, M. Mönkkönen

{"title":"Positive fitness consequences of interspecific interaction with a potential competitor","authors":"Jukka T. Forsman, Janne-Tuomas Seppänen, M. Mönkkönen","doi":"10.1098/rspb.2002.2065","DOIUrl":"https://doi.org/10.1098/rspb.2002.2065","url":null,"abstract":"The coexistence of species sharing mutual resources is usually thought to be limited by negative processes such as interspecific competition. This is because an overlap in resource use leads to negative fitness consequences, and traits favouring avoidance of potential competitors, for example in habitat selection, are therefore selected for. However, species interactions are acknowledged to vary from negative (competition) to mutualism, although empirical evidence for positive interspecific interactions from natural communities of other than plants and sessile animals is scarce. Here, we experimentally examined the habitat selection and its fitness consequences of a migrant bird, the pied flycatcher (Ficedula hypoleuca), in relation to the presence of competitively superior birds, resident titmice (Parus spp.). Experiments were conducted on two spatial scales: landscape and nest–site scale. We demonstrate that pied flycatchers were attracted to and accrued fitness benefits from the presence of titmice. Flycatchers breeding in tight association with titmice initiated breeding earlier, had larger broods and heavier young than solitarily breeding flycatchers. This paradoxical result indicates that species interactions may switch from negative to positive and that the coexistence of species is not always restricted by negative costs caused by other species.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"43 1","pages":"1619 - 1623"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82651651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 153

Adjustments of ejaculation rates in response to risk of sperm competition in a fish, the bitterling (Rhodeus sericeus) 一种鱼的射精率对精子竞争风险的反应。

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2055

U. Candolin, J. Reynolds

引用次数: 75

The role of parasites in the dynamics of a reindeer population 寄生虫在驯鹿种群动态中的作用

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2064

S. Albon, A. Stien, R. Irvine, R. Langvatn, E. Ropstad, O. Halvorsen

{"title":"The role of parasites in the dynamics of a reindeer population","authors":"S. Albon, A. Stien, R. Irvine, R. Langvatn, E. Ropstad, O. Halvorsen","doi":"10.1098/rspb.2002.2064","DOIUrl":"https://doi.org/10.1098/rspb.2002.2064","url":null,"abstract":"Even though theoretical models show that parasites may regulate host population densities, few empirical studies have given support to this hypothesis. We present experimental and observational evidence for a host–parasite interaction where the parasite has sufficient impact on host population dynamics for regulation to occur. During a six year study of the Svalbard reindeer and its parasitic gastrointestinal nematode Ostertagia gruehneri we found that anthelminthic treatment in April–May increased the probability of a reindeer having a calf in the next year, compared with untreated controls. However, treatment did not influence the over–winter survival of the reindeer. The annual variation in the degree to which parasites depressed fecundity was positively related to the abundance of O. gruehneri infection the previous October, which in turn was related to host density two years earlier. In addition to the treatment effect, there was a strong negative effect of winter precipitation on the probability of female reindeer having a calf. A simple matrix model was parameterized using estimates from our experimental and observational data. This model shows that the parasite–mediated effect on fecundity was sufficient to regulate reindeer densities around observed host densities.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"182 1","pages":"1625 - 1632"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83021530","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 334

Estimating the prevalence of inbreeding from incomplete pedigrees 估计不完整家系近亲繁殖的流行程度

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-08-07 DOI: 10.1098/rspb.2002.2035

T. C. Marshall, David W. Coltman, J. Pemberton, J. Slate, J. A. Spalton, F. Guinness, J. A. Smith, J. Pilkington, T. Clutton‐Brock

{"title":"Estimating the prevalence of inbreeding from incomplete pedigrees","authors":"T. C. Marshall, David W. Coltman, J. Pemberton, J. Slate, J. A. Spalton, F. Guinness, J. A. Smith, J. Pilkington, T. Clutton‐Brock","doi":"10.1098/rspb.2002.2035","DOIUrl":"https://doi.org/10.1098/rspb.2002.2035","url":null,"abstract":"A previous review of inbreeding in natural populations suggested that close inbreeding (inbreeding coefficient f = 0.25) is generally rare in wild birds and mammals. However, the review did not assess rates of moderate inbreeding (f = 0.125), which may make a rather larger contribution to overall inbreeding in a population. Furthermore, previous studies may have underestimated the prevalence of inbreeding in wild populations with incomplete pedigrees. By categorizing inbreeding events by the relationship of the parental pair, we suggest a simple method for estimating rates of close and moderate inbreeding from incomplete pedigree data. We applied this method to three wild populations of ruminants: red deer on Rum, Scotland, Soay sheep on Hirta, Scotland and reintroduced Arabian oryx on the Jiddat–al–Harasis, Oman. Although paternal half–sib pairs were the most common category of inbreeding in all three populations, there was considerable variation among populations in the frequencies of the various categories of inbreeding. This variation may be largely explained by differences in population size and dynamics, in maternal and paternal sibship size and in the overlap of reproductive lifespan of consecutive generations. Close and moderate inbreeding appear to be a routine part of breeding behaviour in these ruminant populations.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"11 1","pages":"1533 - 1539"},"PeriodicalIF":0.0,"publicationDate":"2002-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88413749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 92

Delayed effects of cold stress on immune response in laboratory mice 冷应激对实验小鼠免疫反应的延迟效应

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-07-22 DOI: 10.1098/rspb.2002.2054

M. Cichoń, M. Chadzińska, A. Książek, M. Konarzewski

{"title":"Delayed effects of cold stress on immune response in laboratory mice","authors":"M. Cichoń, M. Chadzińska, A. Książek, M. Konarzewski","doi":"10.1098/rspb.2002.2054","DOIUrl":"https://doi.org/10.1098/rspb.2002.2054","url":null,"abstract":"This study was undertaken to examine the trade–off between the cost of thermoregulation and immune function in laboratory mice. Mice were maintained either at 23°C or cold exposed at 5°C for 10 days. Then, they were immunized with sheep red blood cells. Thus, the cold–exposed mice had either experienced or not experienced cold stress prior to immunization. Cold stress elicited a substantial increase in food intake, accompanied by a significant reduction in food digestibility. An increase in mass of metabolically active internal organs (small intestines, heart and kidney) was observed in cold–exposed mice. These findings reassured us that costs of increased thermoregulation caused by cold stress were substantial. The immune response of mice exposed to long–lasting cold stress was significantly lower, but immune response was not affected in short–exposed mice. Differences in immune response between experimental groups accompanied changes in mass of immunocompetent organs (thymus and spleen). Our findings indicate that studies of trade–offs should account for the fact that resource reallocation in response to an environmental challenge may not be immediate. In fact, resource reallocation may be postponed until the new environmental state becomes permanent or until an organism attains physiological adaptation to the current conditions.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"91 1","pages":"1493 - 1497"},"PeriodicalIF":0.0,"publicationDate":"2002-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76181967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 72

Seeing blur: ‘motion sharpenin’ without motion 视觉模糊:没有运动的“运动锐化”

Proceedings of the Royal Society of London. Series B. Biological Sciences Pub Date : 2002-07-22 DOI: 10.1098/rspb.2002.2029

M. Georgeson, S. Hammett

{"title":"Seeing blur: ‘motion sharpenin’ without motion","authors":"M. Georgeson, S. Hammett","doi":"10.1098/rspb.2002.2029","DOIUrl":"https://doi.org/10.1098/rspb.2002.2029","url":null,"abstract":"It is widely supposed that things tend to look blurred when they are moving fast. Previous work has shown that this is true for sharp edges but, paradoxically, blurred edges look sharper when they are moving than when stationary. This is‘motion sharpenin’. We show that blurred edges also look up to 50% sharper when they are presented briefly (8–24 ms) than at longer durations (100–500 ms) without motion. This argues strongly against high–level models of sharpening based specifically on compensation for motion blur. It also argues against a recent, low–level, linear filter model that requires motion to produce sharpening. No linear filter model can explain our finding that sharpening was similar for sinusoidal and non–sinusoidal gratings, since linear filters can never distort sine waves. We also conclude that the idea of a ‘defaul’ assumption of sharpness is not supported by experimental evidence. A possible source of sharpening is a nonlinearity in the contrast response of early visual mechanisms to fast or transient temporal changes, perhaps based on the magnocellular (M–cell) pathway. Our finding that sharpening is not diminished at low contrast sets strong constraints on the nature of the nonlinearity.","PeriodicalId":20585,"journal":{"name":"Proceedings of the Royal Society of London. Series B. Biological Sciences","volume":"8 1","pages":"1429 - 1434"},"PeriodicalIF":0.0,"publicationDate":"2002-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77411567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24