Loss of genetic diversity in isolated populations of an alpine endemic Pilosella alpicola subsp. ullepitschii: effect of long-term vicariance or long-distance dispersal?

2008 ◽  
Vol 275 (3-4) ◽  
pp. 181-191 ◽  
Author(s):  
B. Šingliarová ◽  
J. Chrtek ◽  
P. Mráz
Keyword(s):  
Genetic Diversity ◽  
Long Distance Dispersal ◽  
Isolated Populations ◽  
Long Distance ◽  
Loss Of Genetic Diversity

scholarly journals Genetic consequences of climate change for northern plants

2012 ◽  
Vol 279 (1735) ◽  
pp. 2042-2051 ◽  
Author(s):  
Inger Greve Alsos ◽  
Dorothee Ehrich ◽  
Wilfried Thuiller ◽  
Pernille Bronken Eidesen ◽  
Andreas Tribsch ◽  
...  
Keyword(s):  
Climate Change ◽  
Genetic Diversity ◽  
Species Traits ◽  
Species Distribution Modelling ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Range Reduction ◽  
Global Circulation Models ◽  
Species Vulnerability ◽  
Loss Of Genetic Diversity

Climate change will lead to loss of range for many species, and thus to loss of genetic diversity crucial for their long-term persistence. We analysed range-wide genetic diversity (amplified fragment length polymorphisms) in 9581 samples from 1200 populations of 27 northern plant species, to assess genetic consequences of range reduction and potential association with species traits. We used species distribution modelling (SDM, eight techniques, two global circulation models and two emission scenarios) to predict loss of range and genetic diversity by 2080. Loss of genetic diversity varied considerably among species, and this variation could be explained by dispersal adaptation (up to 57%) and by genetic differentiation among populations ( F ST ; up to 61%). Herbs lacking adaptations for long-distance dispersal were estimated to lose genetic diversity at higher rate than dwarf shrubs adapted to long-distance dispersal. The expected range reduction in these 27 northern species was larger than reported for temperate plants, and all were predicted to lose genetic diversity according to at least one scenario. SDM combined with F ST estimates and/or with species trait information thus allows the prediction of species' vulnerability to climate change, aiding rational prioritization of conservation efforts.

An unexpected new record of the Mediterranean orchid, Ophrys bertolonii (Orchidaceae) in Central Europe

Biologia ◽  
2011 ◽  
Vol 66 (5) ◽  
Author(s):  
Attila Molnár V ◽  
András Máté ◽  
Gábor Sramkó
Keyword(s):  
Central Europe ◽  
New Record ◽  
Dispersal Ability ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Permanent Establishment ◽  
Adriatic Coast ◽  
Northward Expansion ◽  
Mediterranean Plant

AbstractOne flowering specimen of Ophrys bertolonii (s. str.) — a plant with a Circum-Adriatic distribution and hitherto unknown in other regions — was found on 7th May 2010 in the vicinity of Kunadacs (Central Hungary; N 47°00′ E 19°17′). The nearest known populations of this Mediterranean plant inhabit the Adriatic coast (ca. 450 km away) in Croatia, therefore this new occurrence represents a significant long distance dispersal event. The circumstances of the occurrence argue against introduction, but we can not decide now whether this new appearance is temporary or permanent. The permanent establishment of this strictly entomophilous plant requires the presence of its specific pollinator in the close neighbourhood of the habitat. However, no pollination was observed on the three flowers of the plant until 9th May, and one day later the stem had disappeared most likely due to grazing. Whatever the long-term fate of the plant is, this discovery represents a significant long distance (jump) dispersal event, and testifies to the dispersal ability of Ophrys species. Additionally, the appearance of a mature Adriatic plant in Central Europe fits well into the currently observed, climate change driven northward expansion of European orchids, therefore this finding most likely reflects a growing Mediterranean-like climatic influence in the region.

scholarly journals Long-Distance Dispersal Shaped Patterns of Human Genetic Diversity in Eurasia

2015 ◽  
Vol 33 (4) ◽  
pp. 946-958 ◽  
Author(s):  
Isabel Alves ◽  
Miguel Arenas ◽  
Mathias Currat ◽  
Anna Sramkova Hanulova ◽  
Vitor C. Sousa ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Long Distance Dispersal ◽  
Long Distance

Inbreeding and loss of genetic diversity increase extinction risk

2019 ◽  
pp. 31-48
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Inbreeding Depression ◽  
Environmental Changes ◽  
Extinction Risk ◽  
Raw Material ◽  
Heterozygote Advantage ◽  
Isolated Populations ◽  
Survival And Reproduction ◽  
Loss Of Genetic Diversity ◽  
Harmful Effects

Inbreeding reduces survival and reproduction (i.e. it causes inbreeding depression), and thereby increases extinction risk. Inbreeding depression is due to increased homozygosity for harmful alleles and at loci exhibiting heterozygote advantage. Inbreeding depression is nearly universal in sexually reproducing organisms that are diploid or have higher ploidies. Impacts of inbreeding are generally greater in species that naturally outbreed than those that inbreed, in stressful than benign environments, and for fitness than peripheral traits. Harmful effects accumulate across the life cycle, resulting in devastating effects on total fitness in outbreeding species.Species face ubiquitous environmental change and must adapt or they will go extinct. Genetic diversity is the raw material required for evolutionary adaptation. However, loss of genetic diversity is unavoidable in small isolated populations, diminishing their capacity to evolve in response to environmental changes, and thereby increasing extinction risk.

scholarly journals Diversification history and hybridisation of Dacrydium (Podocarpaceae) in remote Oceania

2011 ◽  
Vol 59 (3) ◽  
pp. 262 ◽  
Author(s):  
Gunnar Keppel ◽  
Peter Prentis ◽  
Ed Biffin ◽  
Paul Hodgskiss ◽  
Susana Tuisese ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
New Caledonia ◽  
The Other ◽  
Evolutionary Relationships ◽  
Restricted Range ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Low Genetic Diversity ◽  
Cpdna Sequence ◽  
Relaxed Molecular Clock

We examined evolutionary relationships, hybridisation and genetic diversity in species of Dacrydium (Podocarpaceae) in Remote Oceania, where it is restricted to New Caledonia and Fiji. We used cpDNA sequence (trnL–trnF) data to construct a phylogeny and estimate taxon divergence by using a relaxed molecular clock approach. The phylogeny was verified using allozymes, which were also used to investigate genetic diversity of all species and the hybridisation dynamics of two endangered species, D. guillauminii and D. nidulum. Our results suggested that Dacrydium species in Remote Oceania form a monophyletic group that arose and diversified within the last 20 million years through long-distance dispersal and a range of speciation mechanisms. Whereas we detected no hybridisation between the Fijian species D. nausoriense and D. nidulum, we confirmed hybridisation between D. guillauminii and D. araucarioides in New Caledonia and determined introgression to be assymetric from the widespread D. araucarioides into the rare, restricted-range species D. guillauminii. In addition, D. guillauminii had lower genetic diversity than did the other species of Dacrydium studied, which had genetic diversity similar to that of other gymnosperms. Our results provided evidence for the recent and complex diversification of Dacrydium in Remote Oceania. In addition, low genetic diversity of and introgression from D. araucarioides, are of grave concern for the conservation of D. guillauminii.

scholarly journals Founding Events and the Maintenance of Genetic Diversity in Reintroduced Populations

2021 ◽  
Author(s):  
◽  
Kimberly Anne Miller
Keyword(s):  
Genetic Diversity ◽  
Population Size ◽  
Loss Of Heterozygosity ◽  
Genetic Drift ◽  
Reproductive Output ◽  
Introduced Predators ◽  
Reintroduced Population ◽  
Loss Of Genetic Diversity ◽  
Term Maintenance

<p>As habitat loss, introduced predators, and disease epidemics threaten species worldwide, translocation provides one of the most powerful tools for species conservation. However, reintroduced populations of threatened species are often founded by a small number of individuals (typically 30 in New Zealand) and generally have low success rates. The loss of genetic diversity combined with inbreeding depression in a small reintroduced population could reduce the probability of establishment and persistence. Effective management of genetic diversity is therefore central to the success of reintroduced populations in both the short- and long-term. Using population modelling and empirical data from source and reintroduced populations of skinks and tuatara, I examined factors that influence inbreeding dynamics and the long-term maintenance of genetic diversity in translocated populations. The translocation of gravid females aided in increasing the effective population size after reintroduction. Models showed that supplementation of reintroduced populations reduced the loss of heterozygosity over 10 generations in species with low reproductive output, but not for species with higher output. Harvesting from a reintroduced population for a second-order translocation accelerated the loss of heterozygosity in species with low intrinsic rates of population growth. Male reproductive skew also accelerated the loss of genetic diversity over 10 generations, but the effect was only significant when the population size was small. Further, when populations at opposite ends of a species' historic range are disproportionately vulnerable to extinction and background inbreeding is high, genetic differentiation among populations may be an artefact of an historic genetic gradient coupled with rapid genetic drift. In these situations, marked genetic differences should not preclude hybridising populations to mitigate the risks of inbreeding after reintroduction. These results improve translocation planning for many species by offering guidelines for maximising genetic diversity in founder groups and managing populations to improve the long-term maintenance of diversity. For example, founder groups should be larger than 30 for  reintroductions of species with low reproductive output, high mortality rates after release, highly polygynous mating systems, and high levels of background inbreeding. This study also provides a basis for the development of more complex models of losses of genetic diversity after translocation and how genetic drift may affect the long-term persistence of these valuable  populations.</p>

scholarly journals Anthropogenic river fragmentation reduces long-term viability of the migratory fish Salminus brasiliensis (Characiformes: Bryconidae) populations

2021 ◽  
Vol 19 (2) ◽  
Author(s):  
Josiane Ribolli ◽  
Evoy Zaniboni-Filho ◽  
Carolina Barros Machado ◽  
Tailise Carolina de Souza Guerreiro ◽  
Patrícia Domingues de Freitas ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Anthropogenic Impacts ◽  
Species Conservation ◽  
Migratory Fish ◽  
Effective Population ◽  
Long Distance ◽  
Management Actions ◽  
Population Structure Analysis ◽  
Salminus Brasiliensis

Abstract Life-history, geographical barriers, and damming can shape the genetic diversity of freshwater migratory fish, which are particularly vulnerable to anthropogenic impacts. We investigated the genetic diversity of Salminus brasiliensis, a long-distance migratory species that is recognized as an important provider of ecosystem services. We implemented microsatellite analyses to assess genetic diversity and simulate future scenarios for evaluating the long-term viability of dammed and non-dammed populations from the Uruguay River. High levels of genetic diversity were detected for all sampled populations. However, effective population sizes were lower in the uppermost river stretches, where the landscape is highly fragmented. Population structure analysis indicated two spatial genetic populations. It is suggested that this genetic structure preserves populations partially isolated by an ancient natural barrier, instead of being a result of the presence of dams. The simulated genetic scenarios indicated that genetic variability of S. brasiliensis populations from upstream dams could collapse over the years, mainly due to the reduction in the number of alleles. Therefore, besides helping to better understand issues related to the influence of dams on the genetic diversity of migratory fish, our results are especially relevant for driving local fishery policies and management actions for the species conservation.

Genetic Management of Fragmented Animal and Plant Populations

2017 ◽  
Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark Eldridge ◽  
Michele R. Dudash ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Biological Diversity ◽  
Extinction Risk ◽  
Outbreeding Depression ◽  
Genetic Rescue ◽  
Isolated Populations ◽  
Genetic Management ◽  
Plant Populations ◽  
Loss Of Genetic Diversity

The biological diversity of the planet is being rapidly depleted due to the direct and indirect consequences of human activity. As the size of animal and plant populations decrease and fragmentation increases, loss of genetic diversity reduces their ability to adapt to changes in the environment, with inbreeding and reduced fitness inevitable consequences for many species. Many small isolated populations are going extinct unnecessarily. In many cases, such populations can be genetically rescued by gene flow into them from another population within the species, but this is very rarely done. This novel and authoritative book addresses the issues involved in genetic management of fragmented animal and plant populations, including inbreeding depression, loss of genetic diversity and elevated extinction risk in small isolated populations, augmentation of gene flow, genetic rescue, causes of outbreeding depression and predicting its occurrence, desirability and implementation of genetic translocations to cope with climate change, and defining and diagnosing species for conservation purposes.

scholarly journals Genetic variation in the emblematic Puya raimondii (Bromeliaceae) from Huascarán National Park, Peru

2013 ◽  
Vol 13 (1) ◽  
pp. 67-74 ◽  
Author(s):  
Claudia Teresa Hornung-Leoni ◽  
Victoria Sosa ◽  
June Simpson ◽  
Katia Gil
Keyword(s):  
Genetic Diversity ◽  
Cluster Analysis ◽  
Genetic Variation ◽  
Gene Flow ◽  
Genetic Variability ◽  
National Park ◽  
Conservation Strategies ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Mountain Systems

Puya raimondii, the giant Peruvian and Bolivian terrestrial bromeliad, is an emblematic endemic Andean species well represented in Huascarán National Park in Peru. This park is the largest reserve of puna (high altitude plateau) vegetation. The objective of this study is to report on genetic variation in populations of P. raimondii from Huascarán and neighboring areas. AFLP profiles with four selective primer combinations were retrieved for 60 individuals from different zones. Genetic variability was estimated and a total of 172 bands were detected, of which 79.1% were polymorphic loci. The results showed genetic differentiation among populations, and gene flow. A cluster analysis showed that individuals of P. raimondii populations located in different mountain systems could be grouped together, suggesting long distance dispersal. Thus, conservation strategies for P. raimondii have to take into account exchange between populations located far apart in distance in order to preserve the genetic diversity of this showy species.

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