CORE AND PERIPHERAL POPULATIONS AND GLOBAL CLIMATE CHANGE

1994 ◽  
Vol 42 (4) ◽  
pp. 331-345 ◽  
Author(s):  
Uriel N. Safriel ◽  
Sergei Volis ◽  
Salit Kark

Environmental conditions outside the periphery of a species' distribution prevent population persistence, hence peripheral populations live under conditions different from those of core populations. Peripheral areas are characterized by variable and unstable conditions, relative to core areas. Peripheral populations are expected to be genetically more variable, since the variable conditions induce fluctuating selection, which maintains high genetic diversity. Alternatively, due to marginal ecological conditions at the periphery, populations there are small and isolated; the within-population diversity is low, but the between-population genetic diversity is high due to genetic drift. It is also likely that peripheral populations evolve resistance to extreme conditions. Thus, peripheral populations rather than core ones may be resistant to environmental extremes and changes, such as global climate change induced by the anthropogenically emitted “greenhouse gases”. They should be treated as a biogenetic resource used for rehabilitation and restoration of damaged ecosystems. Climatic transition zones are characterized by a high incidence of species represented by peripheral populations, and therefore should be conserved now as repositories of these resources, to be used in the future for mitigating undesirable effects of global climate change. Preliminary research revealed high phenotypic variability and high genetic diversity in peripheral populations relative to core populations of wild barley and the chukar partridge, respectively.

Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Adverse genetic impacts on fragmented populations are expected to accelerate under global climate change. Many populations and species may not be able to adapt in situ, or move unassisted to suitable habitat. Management may reduce these threats by augmenting genetic diversity to improve the ability to adapt evolutionarily, by translocation, including that outside the species’ historical range (assisted colonization) and by ameliorating non-genetic threats. Global climate change amplifies the need for genetic management of fragmented populations.


Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Adverse genetic impacts on fragmented populations are expected to worsen under global climate change. Many populations and species may not be able to adapt in situ, or to move unassisted to suitable habitat. Management may reduce these threats by augmenting genetic diversity to improve the ability to adapt evolutionarily, by translocation, including that outside the species’ historical range, and by ameliorating non-genetic threats. Global climate change amplifies the need for genetic management of fragmented populations.


2011 ◽  
Vol 279 (1726) ◽  
pp. 39-47 ◽  
Author(s):  
Jim Provan ◽  
Christine A. Maggs

Global climate change is having a significant effect on the distributions of a wide variety of species, causing both range shifts and population extinctions. To date, however, no consensus has emerged on how these processes will affect the range-wide genetic diversity of impacted species. It has been suggested that species that recolonized from low-latitude refugia might harbour high levels of genetic variation in rear-edge populations, and that loss of these populations could cause a disproportionately large reduction in overall genetic diversity in such taxa. In the present study, we have examined the distribution of genetic diversity across the range of the seaweed Chondrus crispus , a species that has exhibited a northward shift in its southern limit in Europe over the last 40 years. Analysis of 19 populations from both sides of the North Atlantic using mitochondrial single nucleotide polymorphisms (SNPs), sequence data from two single-copy nuclear regions and allelic variation at eight microsatellite loci revealed unique genetic variation for all marker classes in the rear-edge populations in Iberia, but not in the rear-edge populations in North America. Palaeodistribution modelling and statistical testing of alternative phylogeographic scenarios indicate that the unique genetic diversity in Iberian populations is a result not only of persistence in the region during the last glacial maximum, but also because this refugium did not contribute substantially to the recolonization of Europe after the retreat of the ice. Consequently, loss of these rear-edge populations as a result of ongoing climate change will have a major effect on the overall genetic diversity of the species, particularly in Europe, and this could compromise the adaptive potential of the species as a whole in the face of future global warming.


2012 ◽  
Vol 22 (4) ◽  
pp. 925-946 ◽  
Author(s):  
Steffen U. Pauls ◽  
Carsten Nowak ◽  
Miklós Bálint ◽  
Markus Pfenninger

2020 ◽  
Vol 18 (2) ◽  
pp. 185-202
Author(s):  
Aleksey A. Ilinov ◽  
Boris V. Raevsky ◽  
Olga V. Chirva

Background. The genetic diversity of forest tree species populations is a key factor contributing to their resistance against negative effects of human activity, and the global climate change. The aim of the present study was to evaluate the state of gene pools of the main forest-forming species in the White Sea watershed. Materials and methods. Five populations of Norway spruce and seven populations of Scotch pine have been selected within the Arctic zone of the European part of Russia (the western part of the White Sea watershed), along with two boundary ones located near the northern borders of the abovementioned species areas. The analysis of the spruce samples had been performed using five nuclear SSR loci, while for the pine samples it was four. DNA fragments were separated on a sequencer CEQ 8000. The main criteria of the genetic diversity (A99%, Ho, He) and F-statistics were calculated. Results. The marginal spruce populations were characterized by the largest magnitude of the genetic diversity (Ho = 0.46; He = 0.47) and isolation (FST = 0.33) compared to other populations of the same species. The differences were statistically significant. All pine populations studied demonstrated a higher level of genetic diversity (Ho = 0.50, He = 0.63) compared to spruce populations. The differences between the boundary and in-area populations were not statistically reliable (FST = 0.04). Conclusion. Our investigation revealed a sufficiently high level of spruce and pine northern populations genetic diversity making them able to withstand expected negative effects of anthropogenic activity and global climate change.


Author(s):  
Richard Frankham ◽  
Jonathan D. Ballou ◽  
Katherine Ralls ◽  
Mark D. B. Eldridge ◽  
Michele R. Dudash ◽  
...  

Genetic management of fragmented populations is one of the major, largely unaddressed issues in biodiversity conservation. Many species across the planet have fragmented distributions with small isolated populations that are potentially suffering from inbreeding and loss of genetic diversity (genetic erosion), leading to elevated extinction risk. Fortunately, genetic deterioration can usually be remedied by gene flow from another population (crossing between populations within species), yet this is rarely done, in part because of fears that crossing may be harmful (but we can predict when this will occur). We address management of gene flow between previously isolated populations and genetic management under global climate change.


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