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1.
    
Since the first molecular study providing evidence for mating outside the pair bond in birds over 30 years ago, >500 studies have reported rates of extra‐pair paternity (EPP) in >300 bird species. Here, we give a detailed overview of the current literature reporting EPP in birds and highlight the sampling biases and patterns in the data set with respect to taxonomy, avian phylogeny and global regions, knowledge of which will be crucial for correct interpretation of results in future comparative studies. Subsequently, we use this comprehensive dataset to simultaneously test the role of several ecological and life history variables. We do not find clear evidence that variation in EPP across socially monogamous species can be explained by latitude, density (coloniality), migration, generation length, genetic structuring (dispersal distance), or climatic variability, after accounting for phylogeny. These results contrast previous studies, most likely due to the large heterogeneity within species in both EPP and the predictor of interest, indicating that using species averages might be unreliable. Despite the absence of broadscale ecological drivers in explaining interspecific variation in EPP, we suggest that certain behaviours and ecological variables might facilitate or constrain EPP, as indicated by our finding that EPP was negatively associated with latitude within noncolonial species, suggesting a role of breeding synchrony. Thus, rather than focussing on general explanations for variation in EPP across all species, a future focus should be on how various aspects of ecology or life history might have driven variation in EPP among groups of species or populations of the same species. Hence, we argue that variation in EPP can be partly explained when taking the right perspective. This comprehensive overview, and particularly the dataset provided herein will create a foundation for further studies.  相似文献   

2.
    
The establishment of marine protected areas (MPAs) can often lead to environmental differences between MPAs and fishing zones. To determine the effects on marine dispersal of environmental dissimilarity between an MPA and fishing zone, we examined the abundance and recruitment patterns of two anemonefishes (Amphiprion frenatus and A. perideraion) that inhabit sea anemones in different management zones (i.e., an MPA and two fishing zones) by performing a field survey and a genetic parentage analysis. We found lower levels of abundance per anemone in the MPA compared to the fishing zones for both species (n = 1,525 anemones, p = .032). The parentage analysis also showed that lower numbers of fishes were recruited from the fishing zones and outside of the study area into each anemone in the MPA than into each anemone in the fishing zones (n = 1,525 anemones, p < .017). However, the number of self‐recruit production per female did not differ between the MPA and fishing zones (n = 384 females, p = .516). Because the ocean currents around the study site were unlikely to cause a lower settlement intensity of larvae in the MPA, the ocean circulation was not considered crucial to the observed abundance and recruitment patterns. Instead, stronger top‐down control and/or a lower density of host anemones in the MPA were potential factors for such patterns. Our results highlight the importance of dissimilarity in a marine environment as a factor that affects connectivity.  相似文献   

3.
    
We have no standard computer algorithm for the reconstruction of parental genotypes from the data generated by molecular studies of progeny arrays. Here I present a computer program that uses the multilocus genotypes of parents and offspring to reconstruct the genotypes of unknown parents contributing gametes to a progeny array for which one parent is known a priori. A second program performs simulations to assess the reliability of the algorithm under various scenarios. These programs will aid scientists engaged in parentage analyses, particularly in species with large clutches.  相似文献   

4.
The neighbourhood model apportions offspring of individual mother plants to self-fertilization, outcrossing to males within a circumscribed area around the mother plant (the neighbourhood), and outcrossing to males outside the neighbourhood. Formerly the model was applied only to haploid pollen gametes in the offspring of conifers, but is extended so that it can be used with genotypic data from diploid offspring of both angiosperms and gymnosperms. In addition, it is shown that the mating parameters can be estimated without independent estimates of allele frequencies in the pollen pools outside the neighbourhood; thus the model might be applied effectively to natural populations exposed to unknown external pollen sources. Parameters of the neighbourhood mating model were estimated for a 10-year-old seed orchard population of the insect-pollinated tree, Eucalyptus regnans, in southeast Australia, which contained a mixture of two geographical provenances (Victoria and Tasmania). The mating patterns revealed were complex. Crosses between trees of the same provenance occurred three times more often than crosses between trees of different provenances. Levels of self-fertilization and patterns of mating within neighbourhoods were influenced by provenance origin, crop fecundity and orchard position (central vs. edge) of mother trees. Gene dispersal, however, was extensive, with approximately 50% of effective pollen gametes coming from males more than 40 m away from mother trees (average distance between neighbouring trees was 7.4 m). Thus, insect pollinators are efficient promoters of cross-fertilization in this orchard, with the result that the effective number of males mating with each female is large.  相似文献   

5.
For many species in nature, a sire's progeny may be distributed among a few or many dams. This poses logistical challenges--typically much greater across males than across females--for assessing means and variances in mating success (number of mates) and reproductive success (number of progeny). Here we overcome these difficulties by exhaustively analyzing a population of green swordtail fish (Xiphophorus helleri) for genetic paternity (and maternity) using a suite of highly polymorphic microsatellite loci. Genetic analyses of 1476 progeny from 69 pregnant females and 158 candidate sires revealed pronounced skews in male reproductive success both within and among broods. These skews were statistically significant, greater than in females, and correlated in males but not in females with mating success. We also compare the standardized variances in swordtail reproductive success to the few such available estimates for other taxa, notably several mammal species with varied mating systems and degrees of sexual dimorphism. The comparison showed that the opportunity for selection on male X. helleri is among the highest yet reported in fishes, and it is intermediate compared to estimates available for mammals. This study is one of a few exhaustive genetic assessments of joint-sex parentage in a natural fish population, and results are relevant to the operation of sexual selection in this sexually dimorphic, high-fecundity species.  相似文献   

6.
    
Large groups of related progeny, as can be collected from discrete egg masses or fruits, present excellent opportunities for parentage analysis by allowing the reconstruction of parental genotypes. Current techniques of parental genotypic reconstruction require the knowledge of at least one parental genotype. Here, I present a new computer program that reconstructs parental genotypes when no parents are known, provided that the progeny array contains only full and half siblings. The prospects for successfully reconstructing parental genotypes for such progeny arrays with unknown parents are nearly as good as those for the case when one parent is known with certainty.  相似文献   

7.
Previous sociobiological studies of tarsiers were invariably based on field observations. Sulawesi tarsiers are known for monogamous or facultative polygynous social mating systems, but, to date, no data exist to describe the genetic mating system. We here bring together behavioral studies and molecular tools for the first time to elucidate mating behavior and kinship within a tarsier population. We investigated the social system of the recently described Tarsius lariang, which researchers have never studied before. Between September and November 2005, we conducted field observations and sampling in central Sulawesi, Indonesia, where this species is endemic. Ten of 11 social groups of the focal population were composed of 1 adult male, 1 adult female, and putative offspring. To enlighten genetic relationships, we used 12 microsatellite loci and mitochondrial DNA sequences of 26 captured and sampled Lariang tarsiers for parentage and relatedness analyses. A significant number of young were the offspring of the sampled group adults, suggesting a predominantly monogamous social and genetic mating system. There is evidence for extrapair young in groups in which adult pairs exhibit close relationships, leading to the assumption that extrapair mating is solicited to avoid inbreeding. Ten of 11 social groups lived in monogamous social systems, indicating monogamy to be the rule in Tarsius lariang.  相似文献   

8.
    
Pollen and seed dispersal are key processes affecting the demographic and evolutionary dynamics of plant species and are also important considerations for the sustainable management of timber trees. Through direct and indirect genetic analyses, we studied the mating system and the extent of pollen and seed dispersal in an economically important timber species, Entandrophragma cylindricum (Meliaceae). We genotyped adult trees, seeds and saplings from a 400‐ha study plot in a natural forest from East Cameroon using eight nuclear microsatellite markers. The species is mainly outcrossed (= 0.92), but seeds from the same fruit are often pollinated by the same father (correlated paternity, rp = 0.77). An average of 4.76 effective pollen donors (Nep) per seed tree contributes to the pollination. Seed dispersal was as extensive as pollen dispersal, with a mean dispersal distance in the study plot approaching 600 m, and immigration rates from outside the plot to the central part of the plot reaching 40% for both pollen and seeds. Extensive pollen‐ and seed‐mediated gene flow is further supported by the weak, fine‐scale spatial genetic structure (Sp statistic = 0.0058), corresponding to historical gene dispersal distances (σg) reaching approximately 1,500 m. Using an original approach, we showed that the relatedness between mating individuals (Fij = 0.06) was higher than expected by chance, given the extent of pollen dispersal distances (expected Fij = 0.02 according to simulations). This remarkable pattern of assortative mating could be a phenomenon of potentially consequential evolutionary and management significance that deserves to be studied in other plant populations.  相似文献   

9.
    
This study introduces the NMπ computer program designed for estimation of plant mating system and seed and pollen dispersal kernels. NMπ is a re‐implementation of the NM+ program and provides new features such as support for multicore processors, explicit treatment of dioecy, the possibility of incorporating uniparentally cytoplasmic markers, the possibility of assessing assortative mating due to phenotypic similarity and inference about offspring genealogies. The probability model of parentage (the neighbourhood model) accounts for missing data and genotyping errors, which can be estimated along with regular parameters of the mating system. The program has virtually no restrictions with respect to a number of individuals, markers or phenotypic characters. A console version of NMπ can be run under a wide variety of operating systems, including Windows, Linux or Mac OS. For Windows users, a graphical user interface is provided to facilitate operating the software. The program, user manual and example data are available on http://www.ukw.edu.pl/pracownicy/plik/igor_chybicki/3694/ .  相似文献   

10.
We isolated and characterized six polymorphic microsatellite loci for the polychaete tubeworm, Hydroides elegans. Two additional loci were not reliably scorable and estimates of heterozygosity were obtained for the other six. In addition, cross‐species amplification was successful for two loci using the congener H. hexagonus. Given that few microsatellite loci are available for polychaetes, these markers will be useful in assessing dispersal and gene flow in H. elegans and probably also other polychaetes.  相似文献   

11.
Although the behaviour of individuals is known to impact the genetic make-up of a population, observed behavioural patterns do not always correspond to patterns of genetic structure. In particular, philopatric or dispersal-limited species often display lower-than-expected values of relatedness or inbreeding suggestive of the presence of cryptic migration, dispersal, or mating behaviours. I used a combination of microsatellite and mark-recapture data to test for the influence of such behaviours in a dispersal-limited species, the Pacific jumping mouse, within a semi-isolated population over three seasons. Despite short dispersal distances and a low rate of first generation migrants, heterozygosities were high and inbreeding values were low. Dispersal was male-biased; interestingly however, this pattern was only present when dispersal was considered to include movement away from paternal home range. Not unexpectedly, males were polygynous; notably, some females were also found to be polyandrous, selecting multiple neighbouring mates for their single annual litter. Patterns of genetic structure were consistent with these more inconspicuous behavioural patterns. Females were more closely related than males and isolation by distance was present only in females. Furthermore, detailed genetic landscapes revealed the existence of strong, significant negative correlations, with areas of low genetic distance among females overlapping spatially with areas of high genetic distance among males. These results support the hypothesis that the detected cryptic components of dispersal and mating behaviour are reducing the likelihood of inbreeding in this population through paternally driven spatial mixing of male genotypes and polyandry of females.  相似文献   

12.
    
Mate-choice theory predicts different optimal mating systems depending on resource availability and habitat stability. Regions with limited resources are thought to promote monogamy. We tested predictions of monogamy in a social rodent, the hoary marmot (Marmota caligata), at the northern climatic extreme of its distribution. Mating systems, social structure and genetic relationships were investigated within and among neighbouring colonies of marmots within a 4 km(2) valley near Kluane National Park, Yukon, Canada, using 21 microsatellite loci. While both monogamous and polygynous populations of hoary marmots have been observed in the southern reaches of this species' range; northern populations of this species are thought to be predominantly monogamous. Contrary to previous studies, we did not find northern hoary marmot social groups to be predominantly monogamous; rather, the mating system seemed to be facultative, varying between monogamy and polygyny within, as well as among, social groups. These findings reveal that the mating systems within colonies of this species are more flexible than previously thought, potentially reflecting local variation in resource availability.  相似文献   

13.
Platyscapa awekei DNA was enriched for several repeat motifs. Sequencing of 48 transformed colonies showed that 22 contained microsatellite loci. Eleven of these loci were tested and six of them proved to be reliable and variable. As expected from these wasps’ biology, FIS was high (= 0.423), indicating frequent sibmating. Notwithstanding, we estimate that dispersing males may secure as much as 8% of all matings.  相似文献   

14.
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 (FIL: ?0.11). Mating did not detectably differ from random across prides (FIT: ?0.02 ns). In addition to being recognizable behavioural and demographic units, prides were statistically distinct genetic units (FLT: 0.07). Some neighbouring prides grouped together both geographically and genetically, forming ‘superprides’ in the population (FZT = 0.05). Thus, although individual prides were genetically distinct, there was an important genetic structure above the level of social groups.  相似文献   

15.
    
Connectivity, the demographic linking of local populations through the dispersal of individuals, is one of the most poorly understood processes in population dynamics, yet has profound implications for conservation and harvest strategies. For marine species with pelagic larvae, direct estimation of connectivity remains logistically challenging and has mostly been limited to single snapshots in time. Here, we document seasonal and interannual patterns of larval dispersal in a metapopulation of the coral reef fish Amphiprion polymnus. A 3‐year record of larval trajectories within and among nine discrete local populations from an area of approximately 35 km was established by determining the natal origin of settled juveniles through DNA parentage analysis. We found that spatial patterns of both self‐recruitment and connectivity were remarkably consistent over time, with a low level of self‐recruitment at the scale of individual sites. Connectivity among sites was common and multidirectional in all years and was not significantly influenced by seasonal variability of predominant surface current directions. However, approximately 75% of the sampled juveniles could not be assigned to parents within the study area, indicating high levels of immigrations from sources outside the study area. The data support predictions that the magnitude and temporal stability of larval connectivity decreases significantly with increasing distance between subpopulations, but increases with the size of subpopulations. Given the considerable effort needed to directly measure larval exchange, the consistent patterns suggest snapshot parentage analyses can provide useful dispersal estimates to inform spatial management decisions.  相似文献   

16.
The application of spatially explicit models of population dynamics to fisheries management and the design marine reserve network systems has been limited due to a lack of empirical estimates of larval dispersal. Here we compared assignment tests and parentage analysis for examining larval retention and connectivity under two different gene flow scenarios using panda clownfish ( Amphiprion polymnus ) in Papua New Guinea. A metapopulation of panda clownfish in Bootless Bay with little or no genetic differentiation among five spatially discrete locations separated by 2–6 km provided the high gene flow scenario. The low gene flow scenario compared the Bootless Bay metapopulation with a genetically distinct population ( F ST = 0.1) located at Schumann Island, New Britain, 1500 km to the northeast. We used assignment tests and parentage analysis based on microsatellite DNA data to identify natal origins of 177 juveniles in Bootless Bay and 73 juveniles at Schumann Island. At low rates of gene flow, assignment tests correctly classified juveniles to their source population. On the other hand, parentage analysis led to an overestimate of self-recruitment within the two populations due to the significant deviation from panmixia when both populations were pooled. At high gene flow (within Bootless Bay), assignment tests underestimated self-recruitment and connectivity among subpopulations, and grossly overestimated self-recruitment within the overall metapopulation. However, the assignment tests did identify immigrants from distant (genetically distinct) populations. Parentage analysis clearly provided the most accurate estimates of connectivity in situations of high gene flow.  相似文献   

17.
Empirical tests of sexual selection theory generally utilize model systems under laboratory settings, and extend conclusions to evolutionary processes occurring in nature. The biological significance of laboratory findings will depend largely on the mating rates of females and patterns of paternity in natural populations, information on which is generally lacking. Here we use microsatellite markers to provide rare estimates of female mating rates and patterns of parentage in a species of tettigoniid, Requena verticalis, which has been used extensively to test theory on the evolution of male parental investment and its influence on the direction of sexual selection. We found that although the number of males having a genetic representation in the female's sperm stores was higher for females collected late in the breeding season than those collected early in the season, overall the female mating rate was lower than that expected from laboratory observations. Analysis of parentage of offspring produced by females at the end of the breeding season revealed that all males represented in the sperm stores fathered offspring, although paternity was biased away from that expected from random sperm utilization. The data show that the complete first male sperm precedence documented in laboratory studies of this species does not persist in natural populations. Our data provide a solid underpinning for conclusions drawn from laboratory studies of this species.  相似文献   

18.
    
Bateman's principles continue to play a major role in the characterization of genetic mating systems in natural populations. The modern manifestations of Bateman's ideas include the opportunity for sexual selection (i.e. Is – the variance in relative mating success), the opportunity for selection (i.e. I – the variance in relative reproductive success) and the Bateman gradient (i.e. βss – the slope of the least‐squares regression of reproductive success on mating success). These variables serve as the foundation for one convenient approach for the quantification of mating systems. However, their estimation presents at least two challenges, which I address here with a new Windows‐based computer software package called batemanater . The first challenge is that confidence intervals for these variables are not easy to calculate. batemanater solves this problem using a bootstrapping approach. The second, more serious, problem is that direct estimates of mating system variables from open populations will typically be biased if some potential progeny or adults are missing from the analysed sample. batemanater addresses this problem using a maximum‐likelihood approach to estimate mating system variables from incompletely sampled breeding populations. The current version of batemanater addresses the problem for systems in which progeny can be collected in groups of half‐ or full‐siblings, as would occur when eggs are laid in discrete masses or offspring occur in pregnant females. batemanater has a user‐friendly graphical interface and thus represents a new, convenient tool for the characterization and comparison of genetic mating systems.  相似文献   

19.
    
The natural regeneration of tree species depends on seed and pollen dispersal. To assess whether limited dispersal could be critical for the sustainability of selective logging practices, we performed parentage analyses in two Central African legume canopy species displaying contrasted floral and fruit traits: Distemonanthus benthamianus and Erythrophleum suaveolens. We also developed new tools linking forward dispersal kernels with backward migration rates to better characterize long‐distance dispersal. Much longer pollen dispersal in D. benthamianus (mean distance dp = 700 m, mp = 52% immigration rate in 6 km2 plot, = 7% selfing rate) than in E. suaveolens (dp = 294 m, mp = 22% in 2 km2 plot, = 20%) might reflect different insect pollinators. At a local scale, secondary seed dispersal by vertebrates led to larger seed dispersal distances in the barochorous E. suaveolens (ds = 175 m) than in the wind‐dispersed D. benthamianus (ds = 71 m). Yet, seed dispersal appeared much more fat‐tailed in the latter species (15%–25% seeds dispersing >500 m), putatively due to storm winds (papery pods). The reproductive success was correlated to trunk diameter in E. suaveolens and crown dominance in D. benthamianus. Contrary to D. benthamianus, E. suaveolens underwent significant assortative mating, increasing further the already high inbreeding of its juveniles due to selfing, which seems offset by strong inbreeding depression. To achieve sustainable exploitation, seed and pollen dispersal distances did not appear limiting, but the natural regeneration of E. suaveolens might become insufficient if all trees above the minimum legal cutting diameter were exploited. This highlights the importance of assessing the diameter structure of reproductive trees for logged species.  相似文献   

20.
The persistence and resilience of many coral reef species are dependent on rates of connectivity among sub-populations. However, despite increasing research efforts, the spatial scale of larval dispersal remains unpredictable for most marine metapopulations. Here, we assess patterns of larval dispersal in the angelfish Centropyge bicolor in Kimbe Bay, Papua New Guinea, using parentage and sibling reconstruction analyses based on 23 microsatellite DNA loci. We found that, contrary to previous findings in this system, self-recruitment (SR) was virtually absent at both the reef (0.4–0.5% at 0.15 km2) and the lagoon scale (0.6–0.8% at approx. 700 km2). While approximately 25% of the collected juveniles were identified as potential siblings, the majority of sibling pairs were sampled from separate reefs. Integrating our findings with earlier research from the same system suggests that geographical setting and life-history traits alone are not suitable predictors of SR and that high levels of localized recruitment are not universal in coral reef fishes.  相似文献   

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