Low genetic diversity and small long-term population sizes in the spring endemic watercress darter, Etheostoma nuchale

2010 ◽  
Vol 11 (6) ◽  
pp. 2267-2279 ◽  
Author(s):  
Brook L. Fluker ◽  
Bernard R. Kuhajda ◽  
Nicholas J. Lang ◽  
Phillip M. Harris
Keyword(s):  
Genetic Diversity ◽  
Low Genetic Diversity ◽  
Population Sizes

Weak genetic structuring suggests historically high genetic connectivity among recently fragmented urban populations of the scincid lizard, Ctenotus fallens

2015 ◽  
Vol 63 (4) ◽  
pp. 279 ◽  
Author(s):  
Josef Krawiec ◽  
Siegfried L. Krauss ◽  
Robert A. Davis ◽  
Peter B. S. Spencer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Large Population ◽  
Geographic Distance ◽  
Genetic Erosion ◽  
Genetic Connectivity ◽  
Genetic Structuring ◽  
Low Genetic Diversity ◽  
Population Sizes

Populations in fragmented urban remnants may be at risk of genetic erosion as a result of reduced gene flow and elevated levels of inbreeding. This may have serious genetic implications for the long-term viability of remnant populations, in addition to the more immediate pressures caused by urbanisation. The population genetic structure of the generalist skink Ctenotus fallens was examined using nine microsatellite markers within and among natural vegetation remnants within a highly fragmented urban matrix in the Perth metropolitan area in Western Australia. These data were compared with samples from a large unfragmented site on the edge of the urban area. Overall, estimates of genetic diversity and inbreeding within all populations were similar and low. Weak genetic differentiation, and a significant association between geographic and genetic distance, suggests historically strong genetic connectivity that decreases with geographic distance. Due to recent fragmentation, and genetic inertia associated with low genetic diversity and large population sizes, it is not possible from these data to infer current genetic connectivity levels. However, the historically high levels of gene flow that our data suggest indicate that a reduction in contemporary connectivity due to fragmentation in C. fallens is likely to result in negative genetic consequences in the longer term.

Nuclear and cytoplasmic genetic diversity reveals long-term population decline in Abies semenovii, an endemic fir of central Asia

2012 ◽  
Vol 42 (12) ◽  
pp. 2142-2152 ◽  
Author(s):  
Svetlana A. Semerikova ◽  
Martin Lascoux ◽  
Vladimir L. Semerikov
Keyword(s):  
Genetic Diversity ◽  
Central Asia ◽  
Population Decline ◽  
Population Expansion ◽  
Nuclear Marker ◽  
Effective Population ◽  
Species Status ◽  
Siberian Fir ◽  
Low Genetic Diversity

The genus Abies is one of the largest conifer genera and many of the marginal species remain poorly characterized. Abies semenovii B. Fedtsch. is a rare mountain fir species from central Asia, and its species status is still disputed. We used both nuclear (allozymes and AFLP) and chloroplastic (cpSSR) markers to show that A. semenovii deserves to be considered as a species and that its low genetic diversity justifies more a proactive conservation policy. First, A. semenovii was significantly differentiated from the Siberian fir Abies sibirica Ledeb. and we did not detect gene flow between the two species. Second, A. semenovii has a very low nuclear genetic diversity, suggesting a prolonged restricted effective population size. Abies semenovii had low cpSSR diversity too but the identification of seven closely related haplotypes suggests that these mutations accumulated recently during a phase of population expansion. This agrees well with the palynological record and is in contrast with the situation observed in another rare Eurasian fir endemic to Kamchatka, Abies gracilis Kom., which was devoid of variation in cpSSRs but that also had a more substantial nuclear marker diversity than A. semenovii, thereby suggesting a more recent but less severe population bottleneck.

Long-term survival despite low genetic diversity in the critically endangered Madagascar fish-eagle

2008 ◽  
Author(s):  
JEFF A. JOHNSON ◽  
RUTH E. TINGAY ◽  
MELANIE CULVER ◽  
FRANK HAILER ◽  
MICHÈLE L. CLARKE ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Critically Endangered ◽  
Term Survival ◽  
Long Term Survival ◽  
Low Genetic Diversity

scholarly journals Diversitas Genetika dan Identifikasi Jenis Kelamin Burung Pelikan (Pelecanus conspicillatus Temminck, 1824) di Penangkaran Taman Margasatwa Ragunan Jakarta

2021 ◽  
Vol 17 (2) ◽  
pp. 105-114
Author(s):  
Anik Budhi Dharmayanthi ◽  
Achmad Muchsinin ◽  
Afriana Pulungan ◽  
Moch Syamsul Arifin Zein
Keyword(s):  
Genetic Diversity ◽  
Nucleotide Diversity ◽  
Haplotype Diversity ◽  
Population Expansion ◽  
Bird Populations ◽  
Low Genetic Diversity ◽  
In Captivity ◽  
D Loop ◽  
Haplotype 1

Pelicans (Pelecanus conspicillatus) is one of the wild species that have a widely distribution. This bird has been successfully bred in Ragunan Zoo, Jakarta. The indicator of inbreeding in the captive population is shown by the decrease of nucleotide diversity and number of haplotypes. The result of genetic diversity analysis using D-loop fragment sequences showed low genetic diversity with nucleotide diversity (p) = 0.00064 ± 0.00010 and haplotype diversity (Hd) = 0.532 ± 0.061 in Pelecanus conspicillatus populations in the Ragunan Zoo. However, negative Fu's Fs value (-3,246) indicates population expansion. We found that there were seven haplotypes in bird populations in the captivity: haplotype 1, 2 and 3 consist of 43 individuals (65.15%), five individuals (7.57%), and 14 individuals (21.21%), respectively. For each haplotype 4, 5, 6 and 7 is only represented by one individual of Pelecanus conspicillatus (1.51%). The sex ratio of males to females is 1: 8.86 with four males identified as haplotype 1, and one male on haplotypes 3, 5 and 7, respectively. Genetic diversity data of the population is an important way for designing long-term plans and goals in efforts to maintain genetic diversity of the Pelecanus conspicillatus population in captivity.

scholarly journals Classification of Genus Acanthopanax in Korea and Genetic Diversity Using Allozymes

2005 ◽  
Vol 54 (1-6) ◽  
pp. 206-210 ◽  
Author(s):  
M. K. Huh ◽  
H. W. Huh
Keyword(s):  
Genetic Diversity ◽  
Representative Sample ◽  
Genetic Relationships ◽  
Woody Species ◽  
Small Population ◽  
Geographic Ranges ◽  
Low Level ◽  
Low Genetic Diversity ◽  
Population Sizes

Abstract Genus Acanthopanax is a long-lived woody species that is primarily distributed throughout Asia. Many species of this genus are regarded as medically and ecologically important. We evaluated a representative sample of the nine taxa with allozymes to estimate genetic relationships within the genus. As some Korean populations were isolated and patchily distributed, they exhibited a low level of genetic diversity. The narrow geographic ranges, artificial distribution of habitats, and small population sizes are proposed as factors contributing to low genetic diversity. Acanthopanax seoulense was similar to A. sessiliflorus, while a cluster of the A. rufinerve population is distant from any other species. A. senticosus is closely related to A. seoulense and A. sessiliflorus, whereas other species (A. koreanum) are more distinct from the Korean populations. Korean species are clustered together and clearly differentiated from the Chinese and Russian Acanthopanax taxa, genus Acanthopanax

scholarly journals Narwhal Genome Reveals Long-Term Low Genetic Diversity despite Current Large Abundance Size

iScience ◽  
2019 ◽  
Vol 15 ◽  
pp. 592-599 ◽  
Author(s):  
Michael V. Westbury ◽  
Bent Petersen ◽  
Eva Garde ◽  
Mads Peter Heide-Jørgensen ◽  
Eline D. Lorenzen
Keyword(s):  
Genetic Diversity ◽  
Low Genetic Diversity

scholarly journals Genetic signature of immigrants and their effect on genetic diversity in the recently established Scandinavian wolf population

2021 ◽  
Author(s):  
Mikael Åkesson ◽  
Øystein Flagstad ◽  
Jouni Aspi ◽  
Ilpo Kojola ◽  
Olof Liberg ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Canis Lupus ◽  
Animal Species ◽  
Allelic Richness ◽  
A Priori ◽  
Management Actions ◽  
Viable Population ◽  
Population Sizes ◽  
Source Populations

AbstractTransboundary connectivity is a key component when conserving and managing animal species that require large areas to maintain viable population sizes. Wolves Canis lupus recolonized the Scandinavian Peninsula in the early 1980s. The population is geographically isolated and relies on immigration to not lose genetic diversity and to maintain long term viability. In this study we address (1) to what extent the genetic diversity among Scandinavian wolves has recovered during 30 years since its foundation in relation to the source populations in Finland and Russia, (2) if immigration has occurred from both Finland and Russia, two countries with very different wolf management and legislative obligations to ensure long term viability of wolves, and (3) if immigrants can be assumed to be unrelated. Using 26 microsatellite loci we found that although the genetic diversity increased among Scandinavian wolves (n = 143), it has not reached the same levels found in Finland (n = 25) or in Russia (n = 19). Low genetic differentiation between Finnish and Russian wolves, complicated our ability to determine the origin of immigrant wolves (n = 20) with respect to nationality. Nevertheless, based on differences in allelic richness and private allelic richness between the two countries, results supported the occurrence of immigration from both countries. A priori assumptions that immigrants are unrelated is non-advisable, since 5.8% of the pair-wise analyzed immigrants were closely related. To maintain long term viability of wolves in Northern Europe, this study highlights the potential and need for management actions that facilitate transboundary dispersal.

scholarly journals Conservation concerns associated with low genetic diversity for K’gari–Fraser Island dingoes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. C. Conroy ◽  
R. W. Lamont ◽  
L. Bridges ◽  
D. Stephens ◽  
A. Wardell-Johnson ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Factors ◽  
Conservation Management ◽  
Future Research ◽  
Effective Population ◽  
Tissue Samples ◽  
Island Populations ◽  
Low Genetic Diversity ◽  
Sample Set

AbstractThe dingo population on world heritage-listed K’gari-Fraser Island (K’gari) is amongst the most well-known in Australia. However, an absence of population genetic data limits capacity for informed conservation management. We used 9 microsatellite loci to compare the levels of genetic diversity and genetic structure of 175 K’gari dingo tissue samples with 264 samples from adjacent mainland regions. Our results demonstrated that the K'gari population has significantly lower genetic diversity than mainland dingoes (AR, HE, PAR; p < 0.05) with a fourfold reduction in effective population size (Ne = 25.7 vs 103.8). There is also strong evidence of genetic differentiation between the island and mainland populations. These results are in accordance with genetic theory for small, isolated, island populations, and most likely the result of low initial diversity and founder effects such as bottlenecks leading to decreased diversity and drift. As the first study to incorporate a large sample set of K’gari dingoes, this provides invaluable baseline data for future research, which should incorporate genetic and demographic monitoring to ensure long-term persistence. Given that human-associated activities will continue to result in dingo mortality, it is critical that genetic factors are considered in conservation management decisions to avoid deleterious consequences for this iconic dingo population.

scholarly journals Genetic Diversity, Inbreeding Level, and Genetic Load in Endangered Snub-Nosed Monkeys (Rhinopithecus)

2020 ◽  
Vol 11 ◽  
Author(s):  
Weimin Kuang ◽  
Jingyang Hu ◽  
Hong Wu ◽  
Xiaotian Fen ◽  
Qingyan Dai ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Large Population ◽  
Population Decline ◽  
Genetic Load ◽  
Term Survival ◽  
Population Sizes ◽  
Genomic Inbreeding ◽  
Inbreeding Level

The snub-nosed monkey genus (Rhinopithecus) comprises five closely related species (R. avunculus, R. bieti, R. brelichi, R. roxellana, and R. strykeri). All are among the world's rarest and most endangered primates. However, the genomic impact associated with their population decline remains unknown. We analyzed population genomic data of all five snub-nosed monkey species to assess their genetic diversity, inbreeding level, and genetic load. For R. roxellana, R. bieti, and R. strykeri, population size is positively correlated with genetic diversity and negatively correlated with levels of inbreeding. Other species, however, which possess small population sizes, such as R. brelichi and R. avunculus, show high levels of genetic diversity and low levels of genomic inbreeding. Similarly, in the three populations of R. roxellana, the Shennongjia population, which possesses the lowest population size, displays a higher level of genetic diversity and lower level of genomic inbreeding. These findings suggest that although R. brelichi and R. avunculus and the Shennongjia population might be at risk, it possess significant genetic diversity and could thus help strengthen their long-term survival potential. Intriguingly, R. roxellana with large population size possess high genetic diversity and low level of genetic load, but they show the highest recent inbreeding level compared with the other snub-nosed monkeys. This suggests that, despite its large population size, R. roxellana has likely been experiencing recent inbreeding, which has not yet affected its mutational load and fitness. Analyses of homozygous-derived deleterious mutations identified in all snub-nosed monkey species indicate that these mutations are affecting immune, especially in smaller population sizes, indicating that the long-term consequences of inbreeding may be resulting in an overall reduction of immune capability in the snub-nosed monkeys, which could provide a dramatic effect on their long-term survival prospects. Altogether, our study provides valuable information concerning the genomic impact of population decline of the snub-nosed monkeys. We revealed multiple counterintuitive and unexpected patterns of genetic diversity in small and large population, which will be essential for conservation management of these endangered species.

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