Simultaneous failure of two sex-allocation invariants: implications for sex-ratio variation within and between populations

Local mate competition (LMC) occurs when male relatives compete for mating opportunities, and this may favour the evolution of female-biased sex allocation. LMC theory is among the most well developed and empirically supported topics in behavioural ecology, clarifies links between kin selection, group selection and game theory, and provides among the best quantitative evidence for Darwinian adaptation in the natural world. Two striking invariants arise from this body of work: the number of sons produced by each female is independent of both female fecundity and also the rate of female dispersal. Both of these invariants have stimulated a great deal of theoretical and empirical research. Here, we show that both of these invariants break down when variation in female fecundity and limited female dispersal are considered in conjunction. Specifically, limited dispersal of females following mating leads to local resource competition (LRC) between female relatives for breeding opportunities, and the daughters of high-fecundity mothers experience such LRC more strongly than do those of low-fecundity mothers. Accordingly, high-fecundity mothers are favoured to invest relatively more in sons, while low-fecundity mothers are favoured to invest relatively more in daughters, and the overall sex ratio of the population sex ratio becomes more female biased as a result.     

Pacific Coral-reef Fishes: The Implications of Behaviour and Ecology of Larvae for Biodiversity and Conservation, and a Reassessment of the Open Population Paradigm

The two-phase life history of most marine fishes and invertebrates has enormous implications for dispersal, population connectivity, and resource management. Pelagic dispersal larvae of marine animals traditionally thought to ensure that populations are widespread, that chances of local extinction are low, and that marine protected areas (MPA) can easily function to replenish both their own populations and those of unprotected areas. Traditionally, dispersal is considered to depend primarily on two variables: pelagic larva duration and far-field currents. These conclusions arise from the open population paradigm and are usually accompanied by a simplifying assumption: larvae are distributed passively by far-field currents. Unfortunately, they ignore the complex reality of circulation and hydrological connectivity of reefs, and do not consider newly-demonstrated behavioural capabilities of coral-reef fish larvae. Far-field circulation varies with depth and often excludes water bodies where propagules are released, and this has important implications for predicting trajectories of even passive larvae. However, larvae are not passive: late-stage larvae of coral-reef fishes can swim faster than currents for long periods, can probably detect reefs at some distance, and can actively find them. This behaviour is flexible, which greatly complicates modelling of larval fish trajectories. Populations at ecological (as opposed to evolutionary) scales are probably less open and more subdivided than previously assumed. All this means that dispersal predictions based solely on far-field water circulation are probably wrong. An emerging view of larval-fish dispersal is articulated that takes these new data and perspectives into account. This emerging view shows that re-evaluation of traditional views in several areas is required, including the contribution of larval-fish biology and dispersal to biodiversity patterns, the way reef fishes are managed, and the way in which MPA are thought to operate. At evolutionary and zoogeographic scales, reef-fish populations are best considered to be open.     

Genetic structure of lions (Panthera leo L.) in the Selous Game Reserve: implications for the evolution of sociality

Abstract We use 14 microsatellites to examine the genetic structure of a lion (Panthera leo L.) population in southern Tanzania. Heterozygosity levels were high (0.75 ± 0.08). Relatedness estimates showed that prides often had close relatives in neighbouring prides, whereas few relatives were found in prides not sharing a border. The drop‐off in relatedness with distance was highly significant. Female pridemates exhibited a higher mean relatedness (0.26 ± 0.07) to one another than did pride males (0.11 ± 0.07). Mean relatedness among females was significantly higher in small prides than in large ones. Prides exhibited significant inbreeding avoidance (F_IL: ?0.11). Mating did not detectably differ from random across prides (F_IT: ?0.02 ns). In addition to being recognizable behavioural and demographic units, prides were statistically distinct genetic units (F_LT: 0.07). Some neighbouring prides grouped together both geographically and genetically, forming ‘superprides’ in the population (F_ZT = 0.05). Thus, although individual prides were genetically distinct, there was an important genetic structure above the level of social groups.     

Spatial variation in population dynamics of juvenile Atlantic salmon: implications for conservation and management

Application of habitat models for predicting expected local densities of Atlantic Salmon Salmo salar in healthy populations has been hampered by a lack of generality in their fit to data from different systems. It is believed that this problem results at least in part from difficulties of effectively integrating factors that act across a range of spatial and temporal scales. Here, as an aid to developing more robust modelling and sampling methodologies, a simple process‐based model for local‐scale dynamics of Atlantic salmon juveniles is developed from first principles by integrating contemporary understanding of self‐thinning, density‐dependent growth and dispersal. The aim is to present a readily understood structure to illustrate the links between spawning and stocking strategies, habitat, migration and fish production. Based on this structure, contemporary understanding of the more complex biological processes that affect density, growth and habitat are discussed in relation to some of the key requirements of managers, including stocking for rehabilitation, assessment of predation impact and development of strategies for sampling populations effectively when deriving habitat‐production models. A major conclusion is that more structured, integrated research is required to provide the basic variables needed to model links between local and global scale habitat and fish production effectively. Nevertheless, application of the current understanding of the biology of Atlantic salmon should be of great benefit to managers in extracting key information from field surveys.     

Variation in local abundance and species richness of stream fishes in relation to dispersal barriers: implications for management and conservation

1. Barriers to immigration, all else being equal, should in principle depress local abundance and reduce local species richness. These issues are particularly relevant to stream‐dwelling species when improperly designed road crossings act as barriers to migration with potential impacts on the viability of upstream populations. However, because abundance and richness are highly spatially and temporally heterogeneous and the relative importance of immigration on demography is uncertain, population‐ and community‐level effects can be difficult to detect. 2. In this study, we tested the effects of potential barriers to upstream movements on the local abundance and species richness of a diverse assemblage of resident stream fishes in the Monongahela National Forest, West Virginia, U.S.A. Fishes were sampled using simple standard techniques above‐ and below road crossings that were either likely or unlikely to be barriers to upstream fish movements (based on physical dimensions of the crossing). We predicted that abundance of resident fishes would be lower in the upstream sections of streams with predicted impassable barriers, that the strength of the effect would vary among species and that variable effects on abundance would translate into lower species richness. 3. Supporting these predictions, the statistical model that best accounted for variation in abundance and species richness included a significant interaction between location (upstream or downstream of crossing) and type (passable or impassable crossing). Stream sections located above predicated impassable culverts had fewer than half the number of species and less than half the total fish abundance, while stream sections above and below passable culverts had essentially equivalent richness and abundance. 4. Our results are consistent with the importance of immigration and population connectivity to local abundance and species richness of stream fishes. In turn, these results suggest that when measured at appropriate scales (multiple streams within catchments), with simple protocols amenable to use by management agencies, differences in local abundance and species richness may serve as indicators of the extent to which road crossings are barriers to fish movement and help determine whether road‐crossing improvements have restored connectivity to stream fish populations and communities.     

Influence of sampling effort on saproxylic beetle diversity assessment: implications for insect monitoring studies in European temperate forests

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Genetic structure of an insect-pollinated and bird-dispersed tropical tree in vegetation fragments and corridors: implications for conservation

In the vegetation corridors that connect small remnants of undisturbed primary forest in the Lavras landscape (Brazil), Protium spruceanum is a representative of a mass-flowering insect-pollinated and bird-dispersed tree. Allozyme variation was quantified from five forest remnants (N = 150) from secondary vegetation corridors linking them (N = 80) to generate information for genetic conservation. The species adhered to H-W equilibrium in all fragments in most of the loci. The results indicated high gene diversity in the fragments and corridors positively correlated with the plant density (r = 0.742, R ² = 0.551, d.f. = 4). We did not find evidence of inbreeding within fragments nor overall The genetic differentiation among remnants was low Evidence of recent bottlenecks by anthropogenic disturbance was detected in fragments (P < 0.05, Wilcoxon sign-rank test). The minimal viable population was estimated for conservation in situ, indicating fragments with possibilities of maintaining genetic equilibrium diversity in the short term (except F3) and in the long term (only F5). The ratios was also calculated to contribute to vegetation enrichment, area recovery or creation of new vegetation corridors. We found high levels of gene diversity in the vegetation corridors, genetic identity with the fragments and absence of inbreeding. Thus, our results suggest that landscape management strategies should therefore consider both the creation of new vegetation corridors and the protection of extant ones.     

Diffusion of nuclear and mitochondrial genes across a zone of secondary contact in the maritime shrew, Sorex maritimensis: implications for the conservation of a Canadian endemic mammal

The maritime shrew, Sorex maritimensis, is a Canadian endemic species with a limited distribution in two provinces in eastern Canada. Phylogeographic analysis of mitochondrial DNA control region and cytochrome b sequences revealed two clades, one found in New Brunswick and the other primarily in Nova Scotia, Canada. We propose that these clades have come back into secondary contact following the Wisconsin glaciation via wetlands on the narrow Isthmus of Chigneto that connects these provinces. Despite evidence of an historic separation of maritime shrew subpopulations in Nova Scotia and New Brunswick, we conclude that shrews in these two regions should be considered a single evolutionary significant unit but separate, semi-isolated management units that should be recognized as such for conservation purposes. The susceptibility of this stenotopic species with limited dispersal capabilities raises concerns about its long-term persistence if climate-change induced habitat fragmentation increases. Maintenance of contiguous wetland habitats is needed to ensure connectivity and gene flow among populations of the maritime shrew.     

Genetic diversity and population structure of the endangered insect species Carabus variolosus in its western distribution range: Implications for conservation

Genetic variation was assessed in the endangered species C. variolosus (Coleoptera: Carabidae), which is listed in the European Habitats and Species Directive. Twelve populations from the north-western margin of its range in Germany and France to the border region between Slovenia and Croatia were investigated for variation at 16 allozyme loci. In general, genetic diversity was rather low as indicated by a mean allelic richness of 1.3 alleles per locus, a mean gene diversity (H _E ) of 0.071 and a mean proportion of polymorphic loci (P _95% ) of 16%. Genetic diversity did not change directionally from the margin towards the core of the range. Very high differentiation between populations (overall F _ST  = 0.465), the results of a Mantel test, and poor accordance between geographical and genetic distance suggest a high degree of isolation of the island-like distributed populations. High F _ST values and genetic distance measures, even between geographically close populations within the same drainage, confirm a very low dispersal power of this habitat specialist of headwater areas and swamps in woodlands, even in comparison with other flightless beetles. It is concluded that the majority of populations are demographically independent. Hierarchical F-statistics indicate that almost half of the genetic variance is found between regions and populations. Therefore, we recommend that conservation efforts consider every population as a management unit and aim to maintain as many populations as possible over as many regions as possible.     

Selecting models to predict the timing of flowering of temperate trees: implications for tree phenology modelling

Classical budburst models (Spring Warming, Sequential, Parallel and Alternating) are unable to fully predict external data, partly because of the methods of optimization used to adjust them. The purpose of this study was to examine different assumptions of budburst models and select those which are best supported by the data, defining new models able to predict external data. Eight models, each differing in one assumption, were fitted and tested using external data. The dataset used to test the models was deduced from aeropalynological data at two stations in France. The results show that some of the models proposed are able to accurately predict external dates of flowering of most of the studied species. The assumptions of those models have been individually tested and shown to improve the models accuracy. Robust estimates of the best predictor models of 12 tree species are presented. The analysis of hypothetical provenance transfer of two species, Buxus sempervirens and Platanus acerifolia, between the two study sites, shows that P. acerifolia estimates are similar in both environments whereas B. sempervirens estimates are variable. This result, which agrees with the genetic characteristics of both species, shows that local adaptation of phenology can also be studied through modelling approaches.     

Global population genetic structure of the starlet anemone <Emphasis Type="Italic">Nematostella vectensis</Emphasis>: multiple introductions and implications for conservation policy

Distinguishing natural versus anthropogenic dispersal of organisms is essential for determining the native range of a species and implementing an effective conservation strategy. For cryptogenic species with limited historical records, molecular data can help to identify introductions. Nematostella vectensis is a small, burrowing estuarine sea anemone found in tidally restricted salt marsh pools. This species’ current distribution extends over three coast lines: (i) the Atlantic coast of North America from Nova Scotia to Georgia, (ii) the Pacific coast of North America from Washington to central California, and (iii) the southeast coast of England. The 1996 IUCN Red List designates N. vectensis as “vulnerable” in England. Amplified fragment length polymorphism (AFLP) fingerprinting of 516 individuals from 24 N. vectensis populations throughout its range and mtDNA sequencing of a subsample of these individuals strongly suggest that anthropogenic dispersal has played a significant role in its current distribution. Certain western Atlantic populations of N. vectensis exhibit greater genetic similarity to Pacific populations or English populations than to other western Atlantic populations. At the same time, F-statistics showing high degrees of genetic differentiation between geographically proximate populations support a low likelihood for natural dispersal between salt marshes. Furthermore, the western Atlantic harbors greater genetic diversity than either England or the eastern Pacific. Collectively, these data clearly imply that N. vectensis is native to the Atlantic coast of North America and that populations along the Pacific coast and in England are cases of successful introduction.     

Linking political and scientifically derived targets for global biodiversity conservation: implications for the expansion of the global network of protected areas

Despite the global network of protected areas covers 12% of the world's land surface, its performance is still unsatisfactory. Although political and scientifically sound conservation targets usually portray different pictures of the task ahead, we show that in terms of priority areas for expanding the global network of reserves, there is much agreement between the political targets of the Convention on Biological Diversity (CBD), and the scientifically derived goals endorsed by international conservation organizations. Here we analyse four global databases to identify priority areas for fulfilling the CBD target of representing 10% of every ecological region within protected areas, and compare the distribution of priority regions for fulfilling that political target, with the distribution of the priority areas for global biodiversity conservation identified by Conservation International, the WWF, and the Wildlife Conservation Society on scientific basis. For 63% (549) of the world's terrestrial ecoregions the CBD 10% target is still not met; fulfilling it requires protecting another 4.6% of the Earth's land surface (6,239,894 km²). Yet, at least 78% of the priority regions for fulfilling that target lay within priority regions for the main global conservation strategies. By pursuing the political target set by the CBD much ancillary gains in terms of other global conservation objectives can be obtained.     

Systematics of AustralianLepidium species (Brassicaceae) and implications for their origin: Evidence from IEF analysis of Rubisco

Variation in subunit polypeptide composition of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) from native AustralianLepidium taxa was analyzed by isoelectric focusing (IEF). Species of grexMonoplocoidea on the one hand, and species of gregesPseudoruderalia andPapillosa on the other, were well separated by Rubisco IEF patterns. The protein data suggest grexMonoplocoidea to be placed in sect.Monoploca whereas gregesPseudoruderalia andPapillosa should be integrated into sect.Dileptium. We suggest that the Rubisco type of American and/or AsianLepidium species was contained in those plants migrating to Australia and evolving into the recent native Australian species. Fossil pollen records and vegetation history indicate that the origin ofLepidium in Australia was restricted to the late Tertiary of Quaternary. Data presented in this study fit best with an immigration by long-distance dispersal of seeds by birds from Asia and/or from South America.     

Resistance to deglycosylation by ammonia of IgA1 O-glycopeptides: implications for the beta-elimination of O-glycans linked to serine and threonine

Pools of O-glycopeptides (and their deglycosylated analogues) derived from trypsin-digested normal human serum IgA1 have been treated with ammonia under conditions reported to result in complete liberation of O-glycans linked to serine and threonine residues in glycopeptides and glycoproteins. MALDI-TOF MS analysis has revealed that only one of the six glycosylated sites is susceptible to beta-elimination under these conditions. It is likely that resistance to beta-elimination is due to very close proximity of proline to the glycosylated serine or threonine residues. Preliminary results using 0.1M NaOH (instead of ammonia) to perform beta-elimination indicated that there was also selective de-O-glycosylation with this reagent, however, these results were complicated by the concomitant hydrolysis of the peptide bonds. These findings may have implications for similarly O-glycosylated peptides and proteins and possibly for other chemical methods that are used to carry out beta-eliminations of O-glycans.