Geographic Structure of Insect Populations: Gene Flow, Phylogeography, and Their Uses

Allozyme variation in the forest grass Milium effusum L. was studied in 2123 populations within each of two equally sized densely sampled areas in northern and southern Sweden. In addition, 25 populations from other parts of Eurasia were studied for comparison. The structure of variation was analysed with both diversity statistics and measures based on allelic richness at a standardised sample size. The species was found to be highly variable, but no clear geographic patterns in the distribution of alleles or in overall genetic differentiation were found, either within the two regions or within the whole sample. Thus, no inferences about the direction of postglacial migration could be made. Obviously, migration and gene flow must have taken place in a manner capable of randomising the distribution of alleles. However, there were clear differences in levels and structuring of the variation between the two regions. Levels of variation, both in terms of genetic diversity and allelic richness, were lower in northern Sweden as compared with southern Sweden. In contrast, different measures of geographic structure all showed higher levels of population differentiation in the northern region. This is interpreted as due to different geomorphological conditions in the two regions, creating a relatively continuous habitat and gene flow in the southern region as compared with the northern region where the species, although common, is confined to narrow and mutually isolated corridors in the landscape.Key words: Milium effusum, allozymes, geographic differentiation, population fragmentation, allelic richness.

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Genetic diversity and biogeography of the boab Adansonia gregorii (Malvaceae: Bombacoideae)

Australian Journal of Botany ◽

10.1071/bt13209 ◽

2014 ◽

Vol 62 (2) ◽

pp. 164 ◽

Cited By ~ 5

Author(s):

Karen L. Bell ◽

Haripriya Rangan ◽

Rachael Fowler ◽

Christian A. Kull ◽

J. D. Pettigrew ◽

...

Keyword(s):

Genetic Diversity ◽

Gene Flow ◽

Population Bottleneck ◽

Geographic Structure ◽

Significant Gene ◽

Spatial Principal Components ◽

High Gene ◽

Components Analysis ◽

The Last Glacial Maximum ◽

The Last Glacial

The Kimberley region of Western Australia is recognised for its high biodiversity and many endemic species, including the charismatic boab tree, Adansonia gregorii F.Muell. (Malvaceae: Bombacoideae). In order to assess the effects of biogeographic barriers on A. gregorii, we examined the genetic diversity and population structure of the tree species across its range in the Kimberley and adjacent areas to the east. Genetic variation at six microsatellite loci in 220 individuals from the entire species range was examined. Five weakly divergent populations, separated by west–east and coast–inland divides, were distinguished using spatial principal components analysis. However, the predominant pattern was low geographic structure and high gene flow. Coalescent analysis detected a population bottleneck and significant gene flow across these inferred biogeographic divides. Climate cycles and coastline changes following the last glacial maximum are implicated in decreases in ancient A. gregorii population size. Of all the potential gene flow vectors, various macropod species and humans are the most likely.

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Do lowland habitats represent barriers to dispersal for a rainforest mayfly, Bungona narilla, in south-east Queensland?

Marine and Freshwater Research ◽

10.1071/mf07202 ◽

2008 ◽

Vol 59 (9) ◽

pp. 761 ◽

Cited By ~ 16

Author(s):

Alison J. McLean ◽

Daniel J. Schmidt ◽

Jane M. Hughes

Keyword(s):

Gene Flow ◽

Aquatic Insect ◽

Restricted Gene Flow ◽

Long Distance Dispersal ◽

Genetic Structuring ◽

Long Distance ◽

Heterogeneous Landscapes ◽

Insect Populations ◽

Dispersal Events ◽

The Relationship

Long-distance dispersal might be an important mechanism for the maintenance of aquatic insect populations in heterogeneous landscapes. However, these events can be difficult to measure by direct observation because the techniques can be time-consuming, expensive and technically difficult. When dispersal results in gene flow within and between populations, patterns of variation can be detected by genetic methods. The levels of population genetic structuring and the relationship between gene flow and geographical distance were assessed in the mayfly species Bungona narilla (Harker, 1957) in rainforest streams in south-east Queensland that are separated by lowland habitats. An analysis of molecular variance based on mitochondrial DNA data, using a fragment of the cytochrome oxidase I gene, revealed significant differentiation between regions, suggesting that maternal gene flow was restricted. A nested clade analysis revealed patterns of historical (contiguous) range expansions and recent restricted gene flow along with some long-distance dispersal events. Our analyses have shown that populations of B. narilla are significantly structured throughout the species range in south-east Queensland and that the low elevation habitats separating the northern and southern populations are restricting gene flow to some extent.

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Was maize domesticated in the Balsas Basin? Complex patterns of genetic divergence, gene flow and ancestral introgressions among Zea subspecies suggest an alternative scenario

10.1101/239707 ◽

2017 ◽

Cited By ~ 2

Author(s):

Alejandra Moreno-Letelier ◽

J.A. Aguirre-Liguori ◽

Maud I. Tenaillon ◽

Daniel Piñero ◽

Brandon S. Gaut ◽

...

Keyword(s):

Zea Mays ◽

Gene Flow ◽

Pacific Coast ◽

Population History ◽

Geographic Structure ◽

The Pacific ◽

History Of ◽

Maize Landraces ◽

Maize Domestication ◽

Shared Polymorphism

AbstractThe study of maize domestication has overlooked the genetic structure within maize’s wild relative teosinte. Prior to investigating the domestication history of maize (Zea mays subspecies mays), one should first understand the population history of teosintes and how they relate to maize. To achieve this, we used 32,739 SNPs obtained from a broad sampling of teosinte populations and 46 maize landraces and a) inferred current and past gene flow among teosinte populations and maize, b) analyzed the degree of introgression among Zea mays subspecies, and c) explored the putative domestication location of maize. We found geographic structure and introgression between Zea mays taxa. Teosinte subspecies have diverged significantly from maize, which indicates that current teosinte populations have evolved mainly independently from maize since the domestication. Our results further suggest that the likely ancestor of maize may maybe have come from Jalisco or the Pacific coast.One Sentence SummaryShared polymorphism in teosinte suggests a Jalisco origin of maize domestication.

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Revision of Cestocampa Condé (Diplura, Campodeidae), with description of a new species from caves in the eastern Iberian Peninsula

Zootaxa ◽

10.11646/zootaxa.3252.1.2 ◽

2012 ◽

Vol 3252 (1) ◽

pp. 43 ◽

Cited By ~ 2

Author(s):

Alberto Sendra ◽

Miquel A. Arnedo ◽

Carles Ribera ◽

S. Teruel ◽

L. Bidegaray-Batista ◽

...

Keyword(s):

New Species ◽

Gene Flow ◽

Iberian Peninsula ◽

Climatic Conditions ◽

Soil Arthropods ◽

Phylogeographic Analysis ◽

Geographic Structure ◽

Limited Dispersal ◽

A New Species ◽

Cox1 Mtdna

A new cave-dwelling Diplura, Cestocampa iberica, is described from the eastern Iberian Peninsula. The new species wascollected in ten caves located in the large karstic area occurring along the Castilian-Valencian branch of the IberianMountain Range. It closely resembles other Cestocampa spp., especially C. gasparoi and C. balcanica. The delimitationof Cestocampa is reviewed. Cestocampa balcanica is redescribed and C. kashiensis is removed from the genus andtransferred to Plusiocampa. A phylogeographic analysis, based on the cox1 mtDNA gene of the new species, reveals aclear geographic structure with high levels of population phylopatry, indicating limited dispersal capabilities as found inother soil arthropods. Evidence of gene flow between nearby localities suggests interconnections among nearby caves.Under certain climatic conditions the species may be able to disperse over the surface, as suggested by one presumed longdistance dispersal event.

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Great Wall blocks gene flow

Nature ◽

10.1038/news030414-3 ◽

2003 ◽

Author(s):

HelenR. Pilcher

Keyword(s):

Gene Flow ◽

Great Wall

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Comparative Analysis of Genetic and Morphological Variation within the Platanthera hyperborea Complex (Orchidaceae)

Systematic Botany ◽

10.1600/036364420x16033962925303 ◽

2020 ◽

Vol 45 (4) ◽

pp. 767-778

Author(s):

Eranga Wettewa ◽

Nick Bailey ◽

Lisa E. Wallace

Keyword(s):

North America ◽

Diploid Species ◽

Morphological Characters ◽

Evolutionary Patterns ◽

Founding Population ◽

Multiple Origins ◽

Geographic Structure ◽

Species Complexes ◽

Nuclear Its ◽

Cryptic Taxa

Abstract—Species complexes present considerable problems for a working taxonomy due to the presence of intraspecific variation, hybridization, polyploidy, and phenotypic plasticity. Understanding evolutionary patterns using molecular markers can allow for a more thorough assessment of evolutionary lineages than traditional morphological markers. In this study, we evaluated genetic diversity and phylogenetic patterns among taxa of the Platanthera hyperborea (Orchidaceae) complex, which includes diploid (Platanthera aquilonis) and polyploid (Platanthera hyperborea, P. huronensis, and P. convallariifolia) taxa spanning North America, Greenland, Iceland, and Asia. We found that three floral morphological characters overlap among the polyploid taxa, but the diploid species has smaller flowers. DNA sequence variation in a plastid (rpL16 intron) and a nuclear (ITS) marker indicated that at least three diploid species have contributed to the genomes of the polyploid taxa, suggesting all are of allopolyploid origin. Platanthera convallariifolia is most like P. dilatata and P. stricta, whereas P. huronensis and P. hyperborea appear to have originated from crosses of P. dilatata and P. aquilonis. Platanthera huronensis, which is found across North America, has multiple origins and reciprocal maternal parentage from the diploid species. By contrast, P. hyperborea, restricted to Greenland and Iceland, appears to have originated from a small founding population of hybrids in which P. dilatata was the maternal parent. Geographic structure was found among polyploid forms in North America. The area of Manitoba, Canada appears to be a contact zone among geographically diverse forms from eastern and western North America. Given the geographic and genetic variation found, we recommend continued recognition of four green-flowered species within this complex, but caution that there may be additional cryptic taxa within North America.

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Differentiation and Interrelations of Two Representatives of Laudakia stellio Complex (Reptilia: Agamidae) in Israel

Russian Journal of Herpetology ◽

10.30906/1026-2296-1997-4-2-102-114 ◽

2011 ◽

Vol 4 (2) ◽

pp. 102-114 ◽

Cited By ~ 2

Author(s):

Evgenyi N. Panov ◽

Larissa Yu. Zykova

Keyword(s):

Population Structure ◽

Gene Flow ◽

Habitat Preference ◽

Additional Data ◽

Near East ◽

Field Studies ◽

Subspecies Level ◽

Limited Gene Flow ◽

Study Sites ◽

And Behavior

Field studies were conducted in Central Negev within the breeding range of Laudakia stellio brachydactyla and in NE Israel (Qyriat Shemona) in the range of an unnamed form (tentatively “Near-East Rock Agama”), during March – May 1996. Additional data have been collected in Jerusalem at a distance of ca. 110 km from the first and about 170 km from the second study sites. A total of 63 individuals were caught and examined. The animals were marked and their subsequent movements were followed. Social and signal behavior of both forms were described and compared. Lizards from Negev and Qyriat Shemona differ from each other sharply in external morphology, habitat preference, population structure, and behavior. The differences obviously exceed the subspecies level. At the same time, the lizards from Jerusalem tend to be intermediate morphologically between those from both above-named localities, which permits admitting the existence of a limited gene flow between lizard populations of Negev and northern Israel. The lizards from NE Israel apparently do not belong to the nominate subspecies of L. stellio and should be regarded as one more subspecies within the species.

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