Inferring population connectivity across the range of the purple-crowned fairy-wren (Malurus coronatus) from mitochondrial DNA and morphology: implications for conservation management

2012 ◽  
Vol 60 (3) ◽  
pp. 199 ◽  
Author(s):  
Anja Skroblin ◽  
Robert Lanfear ◽  
Andrew Cockburn ◽  
Sarah Legge

Knowledge of population structure and patterns of connectivity is required to implement effective conservation measures for the purple-crowned fairy-wren (Malurus coronatus), a threatened endemic of northern Australia. This study aimed to identify barriers to dispersal across the distribution of M. coronatus, investigate the impact that the recent declines may have on population connectivity, and propose conservation actions to maintain natural patterns of gene flow. Analysis of mitochondrial DNA sequences from 87 M. coronatus identified two phylogenetic clusters that corresponded with the phenotypically defined western (M. c. coronatus) and eastern (M. c. macgillivrayi) subspecies. The genetic divergence between these subspecies was consistent with isolation by a natural barrier to gene flow, and supports their separate conservation management. Within the declining M. c. coronatus, the lack of genetic divergence and only slight morphological difference between remnant populations indicates that populations were recently linked by gene flow. It is likely that widespread habitat degradation and the recent extirpation of M. c. coronatus from the Ord River will disrupt connectivity between, and dynamics within, remnant populations. To prevent further declines, conservation of M. coronatus must preserve areas of quality habitat and restore connectivity between isolated populations.

10.5772/25550 ◽  
2012 ◽  
Author(s):  
Roseli Tuan ◽  
Fernanda Pires ◽  
Raquel Gardini Sanches Palasio ◽  
Ricardo Dalla ◽  
Marisa Cristina De Almeida Guimaraes

2002 ◽  
Vol 53 (5) ◽  
pp. 897 ◽  
Author(s):  
Dugald J. McGlashan ◽  
Jane M. Hughes

The 'island' nature of river systems limits the possibility of dispersal in freshwater fish species, with many displaying extensive genetic subdivision across their ranges. We examined the population genetic structure of the predominantly freshwater fish, Pseudomugil signifer, at fine, medium and broad scales using allozyme and mitochondrial DNA techniques. Extensive genetic subdivision across the range (FST = 0.6) at six polymorphic allozyme loci was partitioned mostly among river-system drainages (42%). Patterns of mitochondrial DNA sequences, which mirrored previous taxonomic designations and a terrestrial biogeographic barrier, identified two major groups. The level of divergence between the groups implied a considerable period of isolation. At a more localized scale, significant genetic differences between adjacent drainages implied that flood events are not effective transport mechanisms and indicate that populations of P. signifer in different drainages are essentially independent units. The history of P.�signifer appears to be dominated, at different spatial scales, by long periods of isolation among drainages mediated by changes in sea-level, which merge and isolate drainages haphazardly over time. The chance nature of dispersal, coupled with isolation and potential population size fluctuations, probably leads to the observed complex patterns of genetic divergence.


Genetics ◽  
1981 ◽  
Vol 98 (1) ◽  
pp. 179-197
Author(s):  
Peter E Smouse ◽  
Virginia J Vitzthum ◽  
James V Neel

ABSTRACT Most of the genetic divergence that currently separates populations of Homo sapiens must have arisen during that long period when the local village (or band) was the basic unit of biological evolution. Studies of tribally intact Amerindian groups exhibiting such small-group organization have demonstrated marked genetic divergence between nearby villages. Some of this genetic radiation can be attributed to the effects of random genetic drift over time within these small demes. Some of it, however, might be better ascribed to the consequences of nonrandom genetic assortment at the time of village fission, a recurring event for such groups. Even random genetic assortment at the time of fission would lead to some genetic divergence, due to the finite size of the parent gene pool. We term the genetic consequences of random assortment the random fission effect. Routinely, village fission occurs along family lines, leading to even greater genetic divergence between the daughter villages. We use the term lineal fission effect to describe the genetic consequences of nonrandom assortment and contrast these results with those derived from random assortment.——A formal treatment of random and lineal fission effects is developed, first for the single-locus case, then for the multiple-locus extension. Using this formulation, three Yanomama fission events were examined. Fission in the Yanomama often involves a great deal of mutual hostility between the two factions, so that subsequent gene flow between the two daughter villages is minimal. The first two examples are typical of the Yanomama behavior norm, and are accompanied by a minimum of subsequent gene flow between the daughter villages. In these two cases, the observed divergence values are very large and are also very unlikely under random fission. The lineal fission effect is pronounced. The net impact of lineal fission is to reduce the effective size of the village at the time of fission by a factor of four, relative to expectation from random fission. The third example, however, involved an unusually amicable split of a village, followed by free genetic exchange between the fission products. This "friendly fission" yields an observed divergence value not much in excess of the expectation from random fission.—The long-term consequences of such fission bottlenecks in effective population size are discussed for both intra- and inter-tribal genetic diversity. It appears that the rate of genetic divergence for tribal and subtribal groups may have been somewhat greater than would be expected from classical drift arguments.


2015 ◽  
Vol 5 (1) ◽  
pp. 64-71
Author(s):  
A. R. N. S. Subbanna ◽  
B. Kalyana babu ◽  
J. Stanley ◽  
S. K. Jain ◽  
J. C. Bhatt ◽  
...  

2016 ◽  
Vol 38 (1) ◽  
pp. 124 ◽  
Author(s):  
M. Westerman ◽  
P. A. Woolley

The recent report by Turpin and Bamford (2015) notes a range extension for northern quolls in the Pilbara Bioregion of Western Australia. Mitochondrial DNA sequences derived from five scats show that the new individuals nest within a clade containing all other Pilbara animals. Northern quolls from the Pilbara Bioregion are genetically distinct from congeners from the Kimberley Bioregion. We note that there is no evidence for maternal gene flow between these two regions.


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