Population proteomics: an emerging discipline to study metapopulation ecology

Proteomics research has developed until recently in a relative isolation from other fast-moving disciplines such as ecology and evolution. This is unfortunate since applying proteomics to these disciplines has apparently the potential to open new perspectives. The huge majority of species indeed exhibit over their entire geographic range a metapopulation structure, occupying habitats that are fragmented and heterogeneous in space and/or through time. Traditionally, population genetics is the main tool used to studying metatopulations, as it describes the spatial structure of populations and the level of gene flow between them. In this Viewpoint, we present the reasons why we think that proteomics, because of the level of integration it promotes, has the potential to resolve interesting issues specific to metapopulation biology and adaptive processes.     

A general measure of human population growth regulation

A general measure relating the relative effects of mortality and fertility in damping population growth has been derived from stable population theory. This measure, called the Index of Growth Regulation, can be calculated from a life table and a fertility schedule. It is a single number which integrates the fertility and mortality aspects of a population. It has intuitive meaning, and can be related to social aspects of the population. It can be used to compare any two populations, and for this purpose it has advantages over traditional comparative statistics such as life expectancy, which consider only mortality. By selecting life tables representing general stages of human cultural evolution, it has been shown that hunting-gathering populations were regulated more by mortality than by fertility factors. That is, more growth which could have occurred did not occur due to the incidence of mortality than to the incidence of infecundity. The two forces were of about equal weight before the industrial revolution, and fertility has had a predominant role in population regulation since the beginning of industrialization.     

黄腹角雉的种群数量及其结构研究

1983—1986年在浙江省乌岩岭自然保护区,应用标图法和线路统计法,对野生黄腹角雉种群、数量进行了统计分析。结果表明冬季种群约50只。种群数量有明显的季节变动:繁殖后期数量增加,秋末冬初开始明显下降。黄腹角雉繁殖力低,卵的损失率高,使种群数量上升十分缓慢。成体性比接近1:1,在各样区之间略有差异。在性比偏离1:1较大的样区,亚成体比例较高。     

Evidence of population structuring following population genetic analyses of Fasciola hepatica from Argentina

Fasciola hepatica, the liver fluke, is a trematode parasite that causes disease of economic importance in livestock. As a zoonosis this parasite also poses a risk to human health in areas where it is endemic. Population genetic studies can reveal the mechanisms responsible for genetic structuring (non-panmixia) within parasite populations and provide valuable insights into population dynamics, which in turn enables theoretical predictions of evolutionary dynamics such as the evolution of drug resistance. Here we genotyped 320 F. hepatica collected from 14 definitive hosts from four provinces in Argentina. STRUCTURE analysis indicated three population clusters, and principal coordinate analysis confirmed this, showing population clustering across provinces. Similarly, pairwise F_ST values amongst all four provinces were significant, with standardised pairwise F_ST (F′_ST) ranging from 0.0754 to 0.6327. Therefore, population genetic structure was evident across these four provinces in Argentina. However, there was no evidence of deviation from Hardy–Weinberg equilibrium, so it appears that within these sub-populations there is largely random mating. We identified 263 unique genotypes, which gave a clonal diversity of 82%. Parasites with identical genotypes, clones, accounted for 26.6% of the parasites studied and were found in 12 of the 14 hosts studied, suggesting some clonemate transmission.     

Synchronous dynamics and rates of extinction in spatially structured populations

We explore extinction rates using a spatially arranged set of subpopulations obeying Ricker dynamics. The population system is subjected to dispersal of individuals among the subpopulations as well as to local and global disturbances. We observe a tight positive correlation between global extinction rate and the level of synchrony in dynamics among thesubpopulations. Global disturbances and to a lesser extent, migration, are capable of synchronizing the temporal dynamics of the subpopulations over a rather wide span of the population growth rate r. Local noise decreases synchrony, as does increasing distance among the subpopulations. Synchrony also levels off with increasing r: in the chaotic region, subpopulations almost invariably behave asynchronously. We conclude that it is asynchrony that reduces the probability of global extinctions, not chaos as such: chaos is a special case only. The relationship between global extinction rate, synchronous dynamics and population growth rate is robust to changes in dispersal rates and ranges.     

武夷山木荷种群结构和动态的研究

 本文采用“空间序列代替时间变化”的方法,对武夷山区常绿阔叶林演替过程中木荷种群动态规律进行了研究,结果表明,在木荷种群侵入黄山松幼林向木荷林以及成熟木荷、甜槠、青冈林的发展过程中,种群结构由增长型→稳定型→成熟型→衰退型,空间分布格局由随机型趋于集群分布,种群密度呈现负增长;在成熟木荷、甜槠、青冈林中,由于种间和种内竞争的影响以及林窗效应,木荷种群结构和密度有一个波动性的变化过程,在这一变化过程中,木荷种群仍趋于集群分布。此外,对成熟木荷、甜槠、青冈林中木荷种群不同大小级的分布格局动态进行了研究,表明其幼苗、幼树和中树等级的个体均呈集群分布,而大树等级的个体呈随机分布。根据上述研究结果,对木荷种群动态机制作了探讨。     

中国兽类种群生态学研究进展与展望

兽类种群生态学是现代生态学的核心研究内容。Charles Sutherland Elton在20世纪20年代发现小哺乳动物种群波动现象,标志着现代种群生态学研究的开始。什么因素调节种群波动的问题一直是现代种群生态学领域的研究热点。我国兽类种群生态学研究始于20世纪50年代,迄今,已走过了70年的发展历程,并取得了重要成果。本综述基于20世纪50年代以来我国学者在主流中文期刊及科学引文索引（Science Citation Index,简称SCI）刊物发表的历史文献,分别从种群波动格局、种群统计参数变化、种群内部和外部调节等不同层面评述了我国在鼠类和大型兽类种群生态学的研究历程及现状,同时探讨了未来的研究方向。     

Comparing the genetic diversity and structure of indigenous Korean and Chinese populations of Laodelphax striatellus Fallén using mitochondrial haplotypes

The small brown planthopper, Laodelphax striatellus Fallén, is a major migratory pest from China to Korea and transmits viral diseases of rice plants. In this study, we compared the genetic structures of overwintered indigenous Korean and Chinese populations. The eight Korean populations consisted of 33 haplotypes, and 16 of these were newly identified. The genetic diversity of the Korean population revealed high haplotype diversity (Hd) and low nucleotide diversity (π) of 0.86 ± 0.017 and 0.0024 ± 0.0001 on average, respectively. These values for the Chinese population were Hd = 0.92 ± 0.016 and π = 0.0026 ± 0.0002. Overall, genetic distances by pairwise F_ST were generally low, ranging from ? 0.022 to 0.089. Moreover, the Korean population revealed its ongoing population expansion by showing negative values in the neutrality test (Tajima's D = ? 1.4, Fu's Fs = ? 15.8) and a unimodal pattern in the mismatch distribution analysis. The genetic structures and population relationships were determined using 8 indigenous Korean and 30 Chinese populations by Bayesian approaches and population tree construction, respectively. The genetic structure was inferred as five (K = 5), and all indigenous Korean populations as well as 10 Chinese populations from the Shanghai city, Anhui, Henan, Jiangsu, Liaoning, Shandong, and Zhejiang provinces were grouped into ‘G3’. These results provide partial support for unidirectional gene flow by migratory Chinese populations into Korea. Further analysis conducted using specimens from China and Korea collected in similar periods is necessary to clarify the migration population's origin and its effect on the genetic structure of the indigenous populations.     

Phenotypic consequences of nonrandom migration in the Jirels of Nepal

The phenotypic structure of human populations is shaped by a number of factors such as population size and marital migration. This paper examines the impact of migration on the between-village phenotypic differentiation of the Jirels, a tribal group of eastern Nepal. Data on stature and five cranial measurements for 526 individuals (males and females) are utilized to illustrate the patterns of phenotypic variation. A permutation method is used to generate the phenotypic consequences of random migration constrained to observed levels of movement. The results suggest that Jirel migration is nonrandom and that it produces higher levels of phenotypic differentiation than would result from a random migration process.     

Experimental evidence for density-dependent reproductive output in a coral reef fish

We tested for density-dependent reproduction in a small coral reef fish using field manipulations of density and observational data. Males of the study species, the bridled goby (Coryphopterus glaucofraenum Gill), defend benthic nest sites, within which they spawn with females, and females can spawn repeatedly over an extended breeding season. In small areas, usually only a single male nested at any one time regardless of how many males were present, so the probability of nesting was inversely proportional to density. Nesting males were almost always the largest in the vicinity, suggesting that, for males whose home ranges overlap, social interactions dictate opportunities to nest. Both the per capita rate at which clutches were laid and the number of eggs produced per clutch declined with increasing density, so the per capita rate of egg production was also density dependent. All three measures of fecundity were better predicted by numerical density (numbers per unit area) than biomass (mass of fish per unit area), and were well described as an inverse function of the number of gobies in the vicinity. A simple hypothesis consistent with these results is that a constant number of females spawn, regardless of density. Alternately, the effect of crowding may depend primarily on the number of interacting individuals and affect all females relatively equally. This density dependence could thus contribute to population regulation at the spatial scale over which populations become reproductively closed.     

Population genetics of marine species: the interaction of natural selection and historically differentiated populations

High gene flow, particularly as mediated by larval dispersal, has usually been viewed as sufficient to limit geographic isolation as a major source of population differentiation among marine species. Despite the general observation of relatively little geographic variation among populations of high dispersal marine species many cases of divergence have been observed and natural selection has usually been invoked to explain geographic divergence. Detailed study of several allozyme polymorphisms provided additional evidence that selection may be the predominant force that determines genetic divergence in marine systems. There is, however, growing evidence that marine species with high dispersal are more subdivided than originally thought. The use of multi-locus approaches and the application of molecular techniques have provided new insight into the nature of population divergence in marine species. I argue that (1) many species, which were formerly thought to be unstructured, are in fact subdivided into genetically discrete groups, (2) it is often the case that genetically subdivided populations have distinct evolutionary histories, (3) in many cases, natural selection is the consequence of introgression between these groups, and (4) the combination of molecular assays of both nuclear and mitochondrial DNA and allozyme loci provides the best approach to understanding the evolutionary dynamics of these interacting populations.     

Local adaptation in the monocarpic perennial Carlina vulgaris at different spatial scales across Europe

Spatial variation in environmental conditions can lead to local adaptation of plant populations, particularly if gene flow among populations is low. Many studies have investigated adaptation to contrasting environmental conditions, but little is known about the spatial scale of adaptive evolution. We studied population differentiation and local adaptation at two spatial scales in the monocarpic grassland perennial Carlina vulgaris. We reciprocally transplanted seedlings among five European regions (northwestern Czech Republic, central Germany, Luxembourg, southern Sweden and northwestern Switzerland) and among populations of different sizes within three of the regions. We recorded survival, growth and reproduction over three growing periods. At the regional scale, several performance traits and the individual fitness of C. vulgaris were highest if the plants were grown in their home region and they decreased with increasing transplant distance. The effects are likely due to climatic differences that increased with the geographical distance between regions. At the local scale, there were significant interactions between the effects of the population of origin and the transplant site, but these were not due to an enhanced performance of plants at their home site and they were not related to the geographical or environmental distance between the site of origin and the transplant site. The size of the population of origin did not influence the strength of local adaptation. The results of our study suggest that C. vulgaris consists of regionally adapted genotypes, and that distance is a good predictor of the extent of adaptive differentiation at large scales ( > 200 km) but not at small scales. We conclude that patterns of local adaptation should be taken into account for the efficient preservation of genetic resources, when assessing the status of a plant species and during conservation planning.Electronic supplementary material Supplementary material is available in the online version of this article at and is accessible for authorized users.     

珍稀濒危植物珙桐的生存与人为活动的关系

近年来,由于人类活动的加剧,区域开发项目的增多,致使珍稀濒危树种珙桐的天然分布面积和天然种群数量急剧下降,现天然分布种群已濒临灭绝。为此,本文系统分析了珙桐在不同地质阶段和不同历史阶段的地理分布状况,探讨了促使其地理分布及种数数理动态变化的主要原因,通过大面积的野外调查和查阅资料,提出了珙桐的保护措施。     

Long-term population trends in widespread British moths

The Rothamsted Insect Survey has operated a Great Britain-wide network of light-traps since 1968. From these data we estimated the first ever national abundance indices and 35-year population trends for 338 species of common macro-moths. Although the number of trap sites which run each year is not constant, there is a representative, well-distributed core of traps that have run for 15 years. The proportion of operating sites catching a species and the annual geometric mean catch of successful traps were used to provide estimates of species range and absolute abundance. T, an index of long-term population trends, was used to compare trends among species. T was not biased by trap site turnover. The percentage of species displaying significant decreases (54%) was more than double that displaying increases (22%). Species found throughout Great Britain are decreasing most rapidly in the south and especially the southeast but species with a southerly distribution are increasing. Results of a preliminary overview suggest habitat and climate change may both play a role in changing species dynamics. The existence of estimates of abundances and trends for such a large species pool opens the way for much further research, linking trends with land-use changes, climate change and inter-specific dynamics.     

Comparative population structure of three snook species (Teleostei: Centropomidae) from the eastern central Pacific

Three snook species, Centropomus viridis, Centropomus medius, and Centropomus robalito, from the eastern central Pacific, representing three of the four proposed phyletic lineages in the genus, were analyzed for genetic variability by means of allozyme and RAPD to evaluate the divergence between populations at different levels of dispersal ability and to evaluate the importance of barriers to dispersal in the population subdivision and genetic diversity. Levels of genetic diversity among species estimated by allozymes were similar and consistent with the observed levels of differentiation in marine fish species. Mean heterozygosity ranged from 0.089 for C. viridis to 0.10 for C. robalito. Genetic diversity for the snook species studied was slightly higher than the mean estimation reported in allozymes for 106 marine fish (0.055) and for anadromous fish species (0.043 to 0.057). Multilocus allele frequency homogeneity tests and population-subdivision estimates for both allozyme and RAPD markers revealed the existence of population structure in C. viridis and C. medius, in coincidence with geographic separation of samples, whereas no divergence was detected in C. robalito. This finding may be attributed to the greater population size of C. robalito, which originated by a recent population range expansion, and hence the potential for dispersal is mediated by larval drift. Fluctuations in population size and population range expansion are used to explain discrepancies between levels of genetic diversity and population structure in the studied species. Supplementary material to this paper is available in electronic format at     

Density, climate and varying return points: an analysis of long-term population fluctuations in the threatened European tree frog

Experimental research has identified many putative agents of amphibian decline, yet the population-level consequences of these agents remain unknown, owing to lack of information on compensatory density dependence in natural populations. Here, we investigate the relative importance of intrinsic (density-dependent) and extrinsic (climatic) factors impacting the dynamics of a tree frog (Hyla arborea) population over 22 years. A combination of log-linear density dependence and rainfall (with a 2-year time lag corresponding to development time) explain 75% of the variance in the rate of increase. Such fluctuations around a variable return point might be responsible for the seemingly erratic demography and disequilibrium dynamics of many amphibian populations.     

社鼠种群生态研究

1983—1987年在北京西山研究了社鼠的种群生态学,共捕获标本870只,用胴体重方法划分5个年龄组。种群年龄组成,随季节而有变化。年龄锥体有季节和年度差异。雌雄性比亦有年度变化。在多数年份中,幼体和亚成体的雌性比例高于雄性。社鼠一般在3—4月开始繁殖,9月基本结束,10月见到个别孕鼠。雄性个体性成熟时的睾丸重量在0.8克以上,雌性产仔数平均为5.20。多数雌体一年繁殖2次,个别可繁殖3次。生态寿命约一年半或更长一些。有些雌体参加两年的繁殖活动。社鼠的种群数量,有明显的季节和年度变化。