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Malison RL, Hand BK, Winter E, Giersch JJ, Amish SJ, Whited D, Stanford JA, Luikart G. Landscape connectivity and genetic structure in a mainstem and a tributary stonefly (Plecoptera) species using a novel reference genome. J Hered 2022; 113:453-471. [DOI: 10.1093/jhered/esac025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Accepted: 05/12/2022] [Indexed: 11/13/2022] Open
Abstract
Abstract
Understanding how environmental variation influences population genetic structure can help predict how environmental change influences population connectivity, genetic diversity, and evolutionary potential. We used riverscape genomics modelling to investigate how climatic and habitat variables relate to patterns of genetic variation in two stonefly species, one from mainstem river habitats (Sweltsa coloradensis) and one from tributaries (Sweltsa fidelis) in 40 sites in northwest Montana, USA. We produced a draft genome assembly for S. coloradensis (N50 = 0.251 Mbp, BUSCO > 95% using “insecta_ob9” reference genes). We genotyped 1930 SNPs in 372 individuals for S. coloradensis and 520 SNPs in 153 individuals for S. fidelis. We found higher genetic diversity for S. coloradensis compared to S. fidelis, but nearly identical genetic differentiation among sites within each species (both had global loci median FST = 0.000), despite differences in stream network location. For landscape genomics and testing for selection, we produced a less stringently filtered data set (3454 and 1070 SNPs for S. coloradensis and S. fidelis, respectively). Environmental variables (mean summer precipitation, slope, aspect, mean June stream temperature, land cover type) were correlated with 19 putative adaptive loci for S. coloradensis. but there was only one putative adaptive locus for S. fidelis (correlated with aspect). Interestingly, we also detected potential hybridization between multiple Sweltsa species which has never been previously detected. Studies like ours, that test for adaptive variation in multiple related species are needed to help assess landscape connectivity and the vulnerability of populations and communities to environmental change.
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Affiliation(s)
- Rachel L Malison
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
| | - Brian K Hand
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
| | - Emily Winter
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
| | - J Joseph Giersch
- US Geological Survey, Northern Rocky Mountain Science Center, Glacier National Park, West Glacier, Montana
| | - Stephen J Amish
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
- Conservation Genomics Group, Division of Biological Sciences, University of Montana, Missoula, Montana
| | - Diane Whited
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
| | - Jack A Stanford
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
| | - Gordon Luikart
- The University of Montana, Flathead Lake Biological Station, 32125 Bio Station Lane, Polson, MT
- Conservation Genomics Group, Division of Biological Sciences, University of Montana, Missoula, Montana
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2
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Blanco G, Morinha F. Genetic signatures of population bottlenecks, relatedness, and inbreeding highlight recent and novel conservation concerns in the Egyptian vulture. PeerJ 2021; 9:e11139. [PMID: 33828925 PMCID: PMC8005290 DOI: 10.7717/peerj.11139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 03/01/2021] [Indexed: 11/20/2022] Open
Abstract
The assessment of temporal variation in genetic features can be particularly informative on the factors behind demography and viability of wildlife populations and species. We used molecular methods to evaluate neutral genetic variation, relatedness, bottlenecks, and inbreeding in a declining population of Egyptian vulture (Neophron percnopterus) in central Spain. The results show that the genetic diversity remained relatively stable over a period of twelve years despite the decline in census and effective population sizes in the last decades. A relatively high proportion of nestlings from different and distant territories showed high relatedness in each study year. We also found support for an increasing impact of severe recent (contemporary) rather than distant (historical) past demographic bottlenecks, and the first evidence of inbred mating between full siblings coinciding with lethal malformations in offspring. The inbred nestling with feather malformations was positive to beak and feather disease virus recorded for the first time in this species. These results alert on recent and novel threats potentially affecting health and reducing the adaptive potential of individuals in this threatened species.
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Affiliation(s)
- Guillermo Blanco
- Department of Evolutionary Ecology, National Museum of Natural Sciences (MNCN), Spanish National Research Council (CSIC), Madrid, Spain
| | - Francisco Morinha
- Department of Evolutionary Ecology, National Museum of Natural Sciences (MNCN), Spanish National Research Council (CSIC), Madrid, Spain
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3
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Genetic consequences of social structure in the golden-crowned sifaka. Heredity (Edinb) 2020; 125:328-339. [PMID: 32792649 PMCID: PMC7555495 DOI: 10.1038/s41437-020-0345-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/08/2020] [Accepted: 07/14/2020] [Indexed: 11/08/2022] Open
Abstract
Many species are structured in social groups (SGs) where individuals exhibit complex mating strategies. Yet, most population genetic studies ignore SGs either treating them as small random-mating units or focusing on a higher hierarchical level (the population). Empirical studies acknowledging SGs have found an overall excess of heterozygotes within SGs and usually invoke inbreeding avoidance strategies to explain this finding. However, there is a lack of null models against which ecological theories can be tested and inbreeding avoidance quantified. Here, we investigate inbreeding (deviation from random mating) in an endangered forest-dwelling pair-living lemur species (Propithecus tattersalli). In particular, we measure the inbreeding coefficient (FIS) in empirical data at different scales: SGs, sampling sites and forest patches. We observe high excess of heterozygotes within SGs. The magnitude of this excess is highly dependent on the sampling scheme: while offspring are characterised by a high excess of heterozygotes (FIS < 0), the reproductive pair does not show dramatic departures from Hardy-Weinberg expectations. Moreover, the heterozygosity excess disappears at larger geographic scales (sites and forests). We use a modelling framework that incorporates details of the sifaka mating system but does not include active inbreeding avoidance mechanisms. The simulated data show that, although apparent "random mating" or even inbreeding may occur at the "population" level, outbreeding is maintained within SGs. Altogether our results suggest that social structure leads to high levels of outbreeding without the need for active inbreeding avoidance mechanisms. Thus, demonstrating and measuring the existence of active inbreeding avoidance mechanisms may be more difficult than usually assumed.
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Dubois Q, Lebigre C, Schtickzelle N, Turlure C. Sex, size and timing: Sampling design for reliable population genetics analyses using microsatellite data. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12948] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Quentin Dubois
- Biodiversity Research Centre, Earth and Life InstituteUniversité catholique de Louvain Louvain‐la‐Neuve Belgium
| | - Christophe Lebigre
- Biodiversity Research Centre, Earth and Life InstituteUniversité catholique de Louvain Louvain‐la‐Neuve Belgium
- IFREMER Centre BretagneUnité Sciences et Techniques Halieutiques Plouzané France
| | - Nicolas Schtickzelle
- Biodiversity Research Centre, Earth and Life InstituteUniversité catholique de Louvain Louvain‐la‐Neuve Belgium
| | - Camille Turlure
- Biodiversity Research Centre, Earth and Life InstituteUniversité catholique de Louvain Louvain‐la‐Neuve Belgium
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5
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Myhre AM, Engen S, Saether BE. Effective size of density-dependent populations in fluctuating environments. Evolution 2016; 70:2431-2446. [DOI: 10.1111/evo.13063] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 09/07/2016] [Indexed: 12/13/2022]
Affiliation(s)
- Ane Marlene Myhre
- Department of Biology, Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; N-7491 Trondheim Norway
| | - Steinar Engen
- Department of Mathematical Sciences, Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; N-7491 Trondheim Norway
| | - Bernt-Erik Saether
- Department of Biology, Centre for Biodiversity Dynamics; Norwegian University of Science and Technology; N-7491 Trondheim Norway
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6
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Parreira BR, Chikhi L. On some genetic consequences of social structure, mating systems, dispersal, and sampling. Proc Natl Acad Sci U S A 2015; 112:E3318-26. [PMID: 26080393 PMCID: PMC4491764 DOI: 10.1073/pnas.1414463112] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Many species are spatially and socially organized, with complex social organizations and dispersal patterns that are increasingly documented. Social species typically consist of small age-structured units, where a limited number of individuals monopolize reproduction and exhibit complex mating strategies. Here, we model social groups as age-structured units and investigate the genetic consequences of social structure under distinct mating strategies commonly found in mammals. Our results show that sociality maximizes genotypic diversity, which contradicts the belief that social groups are necessarily subject to strong genetic drift and at high risk of inbreeding depression. Social structure generates an excess of genotypic diversity. This is commonly observed in ecological studies but rarely reported in population genetic studies that ignore social structure. This heterozygosity excess, when detected, is often interpreted as a consequence of inbreeding avoidance mechanisms, but we show that it can occur even in the absence of such mechanisms. Many seemly contradictory results from ecology and population genetics can be reconciled by genetic models that include the complexities of social species. We find that such discrepancies can be explained by the intrinsic properties of social groups and by the sampling strategies of real populations. In particular, the number of social groups and the nature of the individuals that compose samples (e.g., nonreproductive and reproductive individuals) are key factors in generating outbreeding signatures. Sociality is an important component of population structure that needs to be revisited by ecologists and population geneticists alike.
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Affiliation(s)
- Bárbara R Parreira
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; Departamento de Biologia Vegetal, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal;
| | - Lounès Chikhi
- Instituto Gulbenkian de Ciência, 2780-156 Oeiras, Portugal; CNRS, Université Paul Sabatier, Ecole Nationale de Formation Agronomique, UMR5174 EDB (Laboratoire Évolution & Diversité Biologique), F-31062 Toulouse, France
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7
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Lee AM, Engen S, Sæther BE. The influence of persistent individual differences and age at maturity on effective population size. Proc Biol Sci 2011; 278:3303-12. [PMID: 21436183 PMCID: PMC3169030 DOI: 10.1098/rspb.2011.0283] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2011] [Accepted: 03/04/2011] [Indexed: 11/12/2022] Open
Abstract
Ratios of effective populations size, N(e), to census population size, N, are used as a measure of genetic drift in populations. Several life-history parameters have been shown to affect these ratios, including mating system and age at sexual maturation. Using a stochastic matrix model, we examine how different levels of persistent individual differences in mating success among males may affect N(e)/N, and how this relates to generation time. Individual differences of this type are shown to cause a lower N(e)/N ratio than would be expected when mating is independent among seasons. Examining the way in which age at maturity affects N(e)/N, we find that both the direction and magnitude of the effect depends on the survival rate of juveniles in the population. In particular, when maturation is delayed, lowered juvenile survival causes higher levels of genetic drift. In addition, predicted shifts in N(e)/N with changing age at maturity are shown to be dependent on which of the commonly used definitions of census population size, N, is employed. Our results demonstrate that patterns of mating success, as well as juvenile survival probabilities, have substantial effects on rates of genetic drift.
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Affiliation(s)
- Aline Magdalena Lee
- Department of Biology, Centre for Conservation Biology, Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
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Henriques R, Sousa V, Coelho MM. Migration patterns counteract seasonal isolation of Squalius torgalensis, a critically endangered freshwater fish inhabiting a typical Circum-Mediterranean small drainage. CONSERV GENET 2010. [DOI: 10.1007/s10592-010-0078-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Winterrowd MF, Dobson FS, Hoogland JL, Foltz DW. Social Subdivision Influences Effective Population Size in the Colonial-Breeding Black-Tailed Prairie Dog. J Mammal 2009. [DOI: 10.1644/07-mamm-a-210.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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10
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Campbell LG, Husband BC. Impact of clonal growth on effective population size in Hymenoxys herbacea (Asteraceae). Heredity (Edinb) 2005; 94:526-32. [PMID: 15741998 DOI: 10.1038/sj.hdy.6800653] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
By influencing the proliferation of different genotypes, clonal growth can affect the maintenance of genetic variability and magnitude of genetic drift within plant populations. However, estimates of effective population size rarely incorporate the contribution of both asexual and sexual reproduction. We estimated effective size (Ne) for two populations of the clonal, self-incompatible plant, Hymenoxys herbacea, using a stage-structured demographic model for organisms with asexual and sexual recruitment and then examined the impact of reproductive strategy using an elasticity analysis. Plant rosettes monitored in two successive years had high survival rates in both populations (mean 0.94). The mean number of sexually derived recruits per initial ramet was 0.041 (SE 0.039), whereas the mean number of clonal recruits was 0.61 (SE 0.90). Effective size was 1642 and 5769 in the two populations and the Ne/N ratio averaged 0.34, comparable to values for other clonal species. Elasticity analysis indicated that increases in both clonal and sexual recruitment cause an increase in Ne while increasing the variance reduced Ne. However, Ne was more sensitive to changes in the mean and variance of asexual recruitment than sexual recruitment. These results highlight the importance of considering asexual modes of reproduction when examining the role of genetic stochasticity in populations.
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Affiliation(s)
- L G Campbell
- Department of Botany, University of Guelph, Guelph, Ontario, Canada N1G 2W1
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11
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Abstract
It has been proposed that effective size could be estimated in small dioecious population by considering the heterozygote excess observed at neutral markers. When the number of breeders is small, allelic frequencies in males and females will slightly differ due to binomial sampling error. However, this excess of heterozygotes is not generated by dioecy but by the absence of individuals produced through selfing. Consequently, the approach can also be applied to self-incompatible monoecious species. Some inaccuracies in earlier equations expressing effective size as function of the heterozygote excess are also corrected in this paper. The approach is then extended to subdivided populations, where time of sampling becomes crucial. When adults are sampled, the effective size of the entire population can be estimated, whereas when juveniles are sampled, the average effective number of breeders per subpopulations can be estimated. The main limitation of the heterozygote excess method is that it will only perform satisfactorily for populations with a small number of reproducing individuals. While this situation is unlikely to happen frequently at the scale of the entire population, structured populations with small subpopulations are likely to be common. The estimation of the average number of breeders per subpopulations is thus expected to be applicable to many natural populations. The approach is straightforward to compute and independent of equilibrium assumptions. Applications to simulated data suggest the estimation of the number of breeders to be robust to mutation and migration rates, and to specificities of the mating system.
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Affiliation(s)
- François Balloux
- Department of Genetics, University of Cambridge, Downing Street, Cambridge CB2 3EH, United Kingdom.
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12
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Dobson FS, Chesser RK, Hoogland JL, Sugg DW, Foltz DW. The Influence of Social Breeding Groups on Effective Population Size in Black-tailed Prairie Dogs. J Mammal 2004. [DOI: 10.1644/1545-1542(2004)085<0058:tiosbg>2.0.co;2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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13
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Kaeuffer R, Pontier D, Devillard S, Perrin N. Effective size of two feral domestic cat populations (Felis catus L.): effect of the mating system. Mol Ecol 2004; 13:483-90. [PMID: 14717902 DOI: 10.1046/j.1365-294x.2003.02046.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A variety of behavioural traits have substantial effects on the gene dynamics and genetic structure of local populations. The mating system is a plastic trait that varies with environmental conditions in the domestic cat (Felis catus) allowing an intraspecific comparison of the impact of this feature on genetic characteristics of the population. To assess the potential effect of the heterogenity of males' contribution to the next generation on variance effective size, we applied the ecological approach of Nunney & Elam (1994) based upon a demographic and behavioural study, and the genetic 'temporal methods' of Waples (1989) and Berthier et al. (2002) using microsatellite markers. The two cat populations studied were nearly closed, similar in size and survival parameters, but differed in their mating system. Immigration appeared extremely restricted in both cases due to environmental and social constraints. As expected, the ratio of effective size to census number (Ne/N) was higher in the promiscuous cat population (harmonic mean = 42%) than in the polygynous one (33%), when Ne was calculated from the ecological method. Only the genetic results based on Waples' estimator were consistent with the ecological results, but failed to evidence an effect of the mating system. Results based on the estimation of Berthier et al. (2002) were extremely variable, with Ne sometimes exceeding census size. Such low reliability in the genetic results should retain attention for conservation purposes.
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Affiliation(s)
- R Kaeuffer
- UMR-CNRS 5558 'Biométrie et biologie évolutive', Université C. Bernard Lyon 1, 43 Bd du 11 novembre 1918, 69622 Villeurbanne cedex, France
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Balloux F. HETEROZYGOTE EXCESS IN SMALL POPULATIONS AND THE HETEROZYGOTE-EXCESS EFFECTIVE POPULATION SIZE. Evolution 2004. [DOI: 10.1554/03-692] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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Abstract
Abstract
Random mating is the null model central to population genetics. One assumption behind random mating is that individuals mate an infinite number of times. This is obviously unrealistic. Here we show that when each female mates a finite number of times, the effective size of the population is substantially decreased.
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Affiliation(s)
- François Balloux
- Department of Genetics, University of Cambridge, Cambridge CB2 3EH, United Kingdom.
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16
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Abstract
A moment estimator of, the coancestry coefficient for alleles within a population, was described by Weir & Cockerham in 1984 (100) and is still widely cited. The estimate is used by population geneticists to characterize population structure, by ecologists to estimate migration rates, by animal breeders to describe genetic variation, and by forensic scientists to quantify the strength of matching DNA profiles. This review extends the work of Weir & Cockerham by allowing different levels of coancestry for different populations, and by allowing non-zero coancestries between pairs of populations. All estimates are relative to the average value of theta between pairs of populations. Moment estimates for within- and between-population theta values are likely to have large sampling variances, although these may be reduced by combining information over loci. Variances also decrease with the numbers of alleles at a locus, and with the numbers of populations sampled. This review also extends the work of Weir & Cockerham by employing maximum likelihood methods under the assumption that allele frequencies follow the normal distribution over populations. For the case of equal theta values within populations and zero theta values between populations, the maximum likelihood estimate is the same as that given by Robertson & Hill in 1984 (70). The review concludes by relating functions of theta values to times of population divergence under a pure drift model.
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Affiliation(s)
- B S Weir
- Program in Statistical Genetics, Department of Statistics, North Carolina State University, Raleigh, North Carolina 27695-7566, USA
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Turner TF, Wares JP, Gold JR. Genetic effective size is three orders of magnitude smaller than adult census size in an abundant, Estuarine-dependent marine fish (Sciaenops ocellatus). Genetics 2002; 162:1329-39. [PMID: 12454077 PMCID: PMC1462333 DOI: 10.1093/genetics/162.3.1329] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Using eight microsatellite loci and a variety of analytical methods, we estimated genetic effective size (N(e)) of an abundant and long-lived marine fish species, the red drum (Sciaenops ocellatus), in the northern Gulf of Mexico (Gulf). The ratio N(e)/N, where short-term variance N(e) was estimated via the temporal method from shifts in allele-frequency data over four cohorts and where N reflected a current estimate of adult census size in the northern Gulf, was approximately 0.001. In an idealized population, this ratio should approximate unity. The extraordinarily low value of N(e)/N appears to arise from high variance in individual reproductive success and perhaps more importantly from variance in productivity of critical spawning and nursery habitats located in spatially discrete bays and estuaries throughout the northern Gulf. An estimate of N(e) based on a coalescent approach, which measures long-term, inbreeding effective size, was four orders of magnitude lower than the estimate of current census size, suggesting that factors presently driving N(e)/N to low values among red drum in the northern Gulf may have operated similarly in the past. Models that predict N(e)/N exclusively from demographic and life-history features will seriously overestimate N(e) if variance in reproductive success and variance in productivity among spatially discrete demes is underestimated. Our results indicate that these variances, especially variance in productivity among demes, must be large for red drum. Moreover, our study indicates that vertebrate populations with enormous adult census numbers may still be at risk relative to decline and extinction from genetic factors.
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Affiliation(s)
- Thomas F Turner
- Department of Biology and Museum of Southwestern Biology, University of New Mexico, Albuquerque 87131-1091, USA.
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Iizuka M, Tachida H, Matsuda H. A neutral model with fluctuating population size and its effective size. Genetics 2002; 161:381-8. [PMID: 12019252 PMCID: PMC1462101 DOI: 10.1093/genetics/161.1.381] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We consider a diffusion model with neutral alleles whose population size is fluctuating randomly. For this model, the effects of fluctuation of population size on the effective size are investigated. The effective size defined by the equilibrium average heterozygosity is larger than the harmonic mean of population size but smaller than the arithmetic mean of population size. To see explicitly the effects of fluctuation of population size on the effective size, we investigate a special case where population size fluctuates between two distinct states. In some cases, the effective size is very different from the harmonic mean. For this concrete model, we also obtain the stationary distribution of the average heterozygosity. Asymptotic behavior of the effective size is obtained when the population size is large and/or autocorrelation of the fluctuation is weak or strong.
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Affiliation(s)
- Masaru Iizuka
- Division of Mathematics, Kyushu Dental College, Kitakyushu 803-8580, Japan.
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Abstract
Microsatellite markers are routinely used to investigate the genetic structuring of natural populations. The knowledge of how genetic variation is partitioned among populations may have important implications not only in evolutionary biology and ecology, but also in conservation biology. Hence, reliable estimates of population differentiation are crucial to understand the connectivity among populations and represent important tools to develop conservation strategies. The estimation of differentiation is c from Wright's FST and/or Slatkin's RST, an FST -analogue assuming a stepwise mutation model. Both these statistics have their drawbacks. Furthermore, there is no clear consensus over their relative accuracy. In this review, we first discuss the consequences of different temporal and spatial sampling strategies on differentiation estimation. Then, we move to statistical problems directly associated with the estimation of population structuring itself, with particular emphasis on the effects of high mutation rates and mutation patterns of microsatellite loci. Finally, we discuss the biological interpretation of population structuring estimates.
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Affiliation(s)
- François Balloux
- Zoologisches Institut, Universität Bern, CH-3032 Hinterkappelen-Bern, Switzerland.
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