Genetic variation of the Chilean endemic long-haired mouse Abrothrix longipilis (Rodentia, Supramyomorpha, Cricetidae) in a geographical and environmental context

PeerJ ◽

10.7717/peerj.9517 ◽

2020 ◽

Vol 8 ◽

pp. e9517 ◽

Cited By ~ 1

Author(s):

Lourdes Valdez ◽

Marcial Quiroga-Carmona ◽

Guillermo D’Elía

Keyword(s):

Genetic Variation ◽

Isolation By Distance ◽

Demographic History ◽

Mitochondrial Gene ◽

General Pattern ◽

Mediterranean Ecosystem ◽

Gene Genealogy ◽

Quaternary Climate ◽

Mitochondrial Cytochrome B ◽

Isolation By Environment

Quaternary climate and associated vegetational changes affected the fauna of the Chilean Mediterranean ecosystem. Here we studied the genetic variation of the long-haired mouse, Abrothrix longipilis, a sigmodontine rodent endemic to this area. Within an environmentally explicit context, we examined the geographic distribution of the genetic diversity and demographic history of the species based on sequences of the mitochondrial Cytochrome-b gene of 50 individuals from 13 localities and a large panel of single nucleotide polymorphisms of 17 individuals from 6 localities. The gene genealogy of A. longipilis revealed three intraspecific lineages that are allopatric and latitudinally segregated (northern, central, and southern lineages) with an estimated crown age for the whole species clade of 552.3 kyr B.P. A principal component analysis based on 336,596 SNP loci is in line with the information given by the the mitochondrial gene genealogy. Along its complete distributional range, A. longipilis showed patterns of isolation by distance and also isolation by environment. The general pattern of historical demography showed stability for most intraspecific lineages of A. longipilis. Northern and central lineages showed signals of historical demographic stability, while the southern lineage showed contrasting signals. In agreement with this, the niche models performed showed that in the northern range of A. longipilis, areas of high suitability for this species increased towards the present time; areas of central range would have remained relatively stable, while southern areas would have experienced more change through time. In summary, our study shows three distinct allopatric lineages of A. longipilis, each showing slightly different demographic history.

Climatic Refugia and Geographical Isolation Contribute to the Speciation and Genetic Divergence in Himalayan-Hengduan Tree Peonies (Paeonia delavayi and Paeonia ludlowii)

Frontiers in Genetics ◽

10.3389/fgene.2020.595334 ◽

2021 ◽

Vol 11 ◽

Author(s):

Yu-Juan Zhao ◽

Gen-Shen Yin ◽

Yue-Zhi Pan ◽

Bo Tian ◽

Xun Gong

Keyword(s):

Genetic Variation ◽

Late Quaternary ◽

Demographic History ◽

Nuclear Gene ◽

Genetic Distances ◽

Population Divergence ◽

Widespread Species ◽

Isolation With Migration ◽

Isolation By Environment ◽

Paeonia Delavayi

Himalaya and Hengduan Mountains (HHM) is a biodiversity hotspot, and very rich in endemic species. Previous phylogeographical studies proposed different hypotheses (vicariance and climate-driven speciation) in explaining diversification and the observed pattern of extant biodiversity, but it is likely that taxa are forming in this area in species-specific ways. Here, we reexplored the phylogenetic relationship and tested the corresponding hypotheses within Paeonia subsect. Delavayanae composed of one widespread species (Paeonia delavayi) and the other geographically confined species (Paeonia ludlowii). We gathered genetic variation data at three chloroplast DNA fragments and one nuclear gene from 335 individuals of 34 populations sampled from HHM. We performed a combination of population genetic summary statistics, isolation-with-migration divergence models, isolation by environment, and demographic history analyses. We found evidence for the current taxonomic treatment that P. ludlowii and P. delavayi are two different species with significant genetic differentiation. The significant isolation by environment was revealed within all sampled populations but genetic distances only explained by geographical distances within P. delavayi populations. The results of population divergence models and demographic history analyses indicated a progenitor–derivative relationship and the Late Quaternary divergence without gene flow between them. The coalescence of all sampled cpDNA haplotypes could date to the Late Miocene, and P. delavayi populations probably underwent a severe bottleneck in population size during the last glacial period. Genetic variation in Paeonia subsect. Delavayanae is associated with geographical and environmental distances. These findings point to the importance of geological and climatic changes as causes of the speciation event and lineage diversification within Paeonia subsect. Delavayanae.

Genetic and morphometric divergence in the Garnet-Throated Hummingbird Lamprolaima rhami (Aves: Trochilidae)

PeerJ ◽

10.7717/peerj.5733 ◽

2018 ◽

Vol 6 ◽

pp. e5733 ◽

Cited By ~ 4

Author(s):

Luz E. Zamudio-Beltrán ◽

Blanca E. Hernández-Baños

Keyword(s):

Genetic Variation ◽

El Salvador ◽

Species Delimitation ◽

Biological Diversity ◽

Environmental Changes ◽

Isolation By Distance ◽

Demographic History ◽

Cloud Forests ◽

Divergence Time Estimates ◽

Geographic Structure

Cloud forests are one of the most endangered ecosystems in the Americas, as well as one of the richest in biological diversity in the world. The species inhabiting these forests are susceptible to environmental changes and characterized by high levels of geographic structure. The Garnet-Throated Hummingbird, Lamprolaima rhami, mainly inhabits cloud forests, but can also be found in other habitats. This species has a highly restricted distribution in Mesoamerica, and five disjunct regions have been delimited within the current geographic distribution of the species from Mexico to Honduras. According to variation in size and color, three subspecies have been described: L. r. rhami restricted to the Mexican highlands and Guatemala, L. r. occidentalis distributed in Guerrero (Mexico), and L. r. saturatior, distributed in the highlands from Honduras and El Salvador. We analyzed the levels of geographic structure in L. rhami and its taxonomic implications. We used mitochondrial and nuclear DNA to analyze genetic variation, demographic history, divergence times, reconstructed a multilocus phylogeny, and performed a species delimitation analyses. We also evaluated morphological variation in 208 specimens. We found high levels of genetic differentiation in three groups, and significant variation in morphological traits corresponding with the disjunct geographic populations. L. rhami presents population stability with the highest genetic variation explained by differences between populations. Divergence time estimates suggest that L. rhami split from its sister group around 10.55 million years ago, and the diversification of the complex was dated ca. 0.207 Mya. The hypotheses tested in the species delimitation analyses validated three independent lineages corresponding to three disjunct populations. This study provides evidence of genetic and/or morphometric differentiation between populations in the L. rhami complex where four separate evolutionary lineages are supported: (1) populations from the Sierra Madre Oriental and the highlands of Oaxaca (rhami), (2) populations from the highlands of Guerrero (occidentalis), (3) populations from the highlands of Chiapas and Guatemala (this is a non-previously proposed potential taxon: tacanensis), and (4) populations from the highlands of Honduras and El Salvador (saturatior). The main promoters of the geographic structure found in the L. rhami complex are likely the Isthmus of Tehuantepec as a geographic barrier, isolation by distance resulting from habitat fragmentation, and climatic conditions during the Pleistocene.

Spatial, climate, and ploidy factors drive genomic diversity and resilience in the widespread grass Themeda triandra

10.1101/864298 ◽

2019 ◽

Author(s):

CW Ahrens ◽

EA James ◽

AD Miller ◽

NC Aitken ◽

JO Borevitz ◽

...

Keyword(s):

Genetic Variation ◽

Isolation By Distance ◽

Management Strategies ◽

Genomic Variation ◽

Genomic Diversity ◽

List Type ◽

Themeda Triandra ◽

Reduced Representation ◽

Isolation By Environment ◽

Susceptible Populations

SummaryFragmented grassland ecosystems, and the species that shape them, are under immense pressure. Restoration and management strategies should include genetic diversity and adaptive capacity to improve success but these data are generally unavailable. Therefore, we use the foundational grass, Themeda triandra, to test how spatial, environmental, and ploidy factors shape patterns of genetic variation.We used reduced-representation genome sequencing on 487 samples from 52 locations to answer fundamental questions about how the distribution of genomic diversity and ploidy polymorphism supports adaptation to harsher climates. We explicitly quantified isolation-by-distance (IBD), isolation-by-environment (IBE), and predicted population genomic vulnerability in 2070.We found that a majority (54%) of the genomic variation could be attributed to IBD, while 22% of the genomic variation could be explained by four climate variables showing IBE. Results indicate that heterogeneous patterns of vulnerability across populations are due to genetic variation, multiple climate factors, and ploidy polymorphism, which lessened genomic vulnerability in the most susceptible populations.These results indicate that restoration and management of T. triandra should incorporate knowledge of genomic diversity and ploidy polymorphisms to increase the likelihood of population persistence and restoration success in areas that will become hotter and more arid.

Evolutionary history of a relict conifer, Pseudotaxus chienii (Taxaceae), in south-east China during the late Neogene: old lineage, young populations

Annals of Botany ◽

10.1093/aob/mcz153 ◽

2019 ◽

Vol 125 (1) ◽

pp. 105-117 ◽

Cited By ~ 2

Author(s):

Yixuan Kou ◽

Li Zhang ◽

Dengmei Fan ◽

Shanmei Cheng ◽

Dezhu Li ◽

...

Keyword(s):

Dna Sequences ◽

Genetic Divergence ◽

Evolutionary History ◽

Isolation By Distance ◽

Demographic History ◽

East China ◽

Population Divergence ◽

Isolation By Environment ◽

Late Neogene ◽

History Of

Abstract Background and Aims Many monotypic gymnosperm lineages in south-east China paradoxically remain in relict status despite long evolutionary histories and ample opportunities for allopatric speciation, but this paradox has received little attention and has yet to be resolved. Here, we address this issue by investigating the evolutionary history of a relict conifer, Pseudotaxus chienii (Taxaceae). Methods DNA sequences from two chloroplast regions and 14 nuclear loci were obtained for 134 samples. The demographic history was inferred and the contribution of isolation by environment (IBE) in patterning genetic divergence was compared with that of isolation by distance (IBD). Key Results Three genetic clusters were identified. Approximate Bayesian computation analyses showed that the three clusters diverged in the late Pliocene (~3.68 Ma) and two admixture events were detected. Asymmetric gene flow and similar population divergence times (~ 3.74 Ma) were characterized using the isolation with migration model. Neither IBD nor IBE contributed significantly to genetic divergence, and the contribution of IBE was much smaller than that of IBD. Conclusions These results suggest that several monotypic relict gymnosperm lineages like P. chienii in south-east China did not remain in situ and undiversified for millions of years. On the contrary, they have been evolving and the extant populations have become established more recently, having insufficient time to speciate. Our findings provide a new perspective for understanding the formation and evolution of the relict gymnosperm flora of China as well as of the Sino-Japanese Flora.

Demographic modeling informs functional connectivity and management interventions in Graham’s beardtongue

Conservation Genetics ◽

10.1007/s10592-021-01392-9 ◽

2021 ◽

Author(s):

Matthew R. Jones ◽

Daniel E. Winkler ◽

Rob Massatti

Keyword(s):

Population Structure ◽

Genetic Variation ◽

Functional Connectivity ◽

Isolation By Distance ◽

Management Practice ◽

Demographic History ◽

Principal Component ◽

Management Options ◽

Demographic Modeling ◽

Management Interventions

AbstractFunctional connectivity (i.e., the movement of individuals across a landscape) is essential for the maintenance of genetic variation and persistence of rare species. However, illuminating the processes influencing functional connectivity and ultimately translating this knowledge into management practice remains a fundamental challenge. Here, we combine various population structure analyses with pairwise, population-specific demographic modeling to investigate historical functional connectivity in Graham’s beardtongue (Penstemon grahamii), a rare plant narrowly distributed across a dryland region of the western US. While principal component and population structure analyses indicated an isolation-by-distance pattern of differentiation across the species’ range, spatial inferences of effective migration exposed an abrupt shift in population ancestry near the range center. To understand these seemingly conflicting patterns, we tested various models of historical gene flow and found evidence for recent admixture (~ 3400 generations ago) between populations near the range center. This historical perspective reconciles population structure patterns and suggests management efforts should focus on maintaining connectivity between these previously isolated lineages to promote the ongoing transfer of genetic variation. Beyond providing species-specific knowledge to inform management options, our study highlights how understanding demographic history may be critical to guide conservation efforts when interpreting population genetic patterns and inferring functional connectivity.

Environmental and geographic data optimize ex situ collections and the preservation of adaptive evolutionary potential

10.1101/2020.02.22.960989 ◽

2020 ◽

Author(s):

Lionel N. Di Santo ◽

Jill A. Hamilton

Keyword(s):

Genetic Variation ◽

Genetic Differentiation ◽

Plant Species ◽

Isolation By Distance ◽

Allelic Diversity ◽

Genetic Data ◽

Ex Situ ◽

Evolutionary Potential ◽

Isolation By Environment ◽

The Impact

AbstractMaintenance of biodiversity, through seed banks and botanical gardens where the wealth of species’ genetic variation may be preserved ex situ, is a major goal of conservation. However, challenges can persist in optimizing ex situ collections where trade-offs exist between expense, effort, and conserving species evolutionary potential, particularly when genetic data is not available. Within this context, we evaluate the genetic consequences of guiding population preservation using geographic (isolation-by-distance, IBD) and environmental (isolation-by-environment, IBE) data for ex situ collections where provenance data is available. We use 19 genetic and genomic datasets from 15 plant species to (i) assess the proportion of population genetic differentiation explained by geographic and environmental factors, and (ii) simulate ex situ collections prioritizing source populations based on pairwise geographic or environmental distances. Specifically, we test the impact prioritizing sampling based on environmental and geographic distances may have on capturing neutral, functional or putatively adaptive genetic diversity and differentiation. We find that collectively IBD and IBE explain a substantial proportion of genetic differences among functional (median 45%) and adaptive (median 71%) loci, but not for neutral loci (median 21.5%). Simulated ex situ collections reveal that inclusion of IBD and IBE increases both allelic diversity and genetic differentiation captured among populations, particularly for loci that may be important for adaptation. Thus, prioritizing population collections using environmental and geographic distance data can impact genetic variation captured ex situ. This provides value for the vast majority of plant species for which we have no genetic data, informing conservation of genetic variation needed to maintain evolutionary potential within collections.

Linking patterns of genetic variation to processes of diversification in Malaysian torrent frogs (Anura: Ranidae:Amolops): a landscape genomics approach

10.1101/628891 ◽

2019 ◽

Cited By ~ 2

Author(s):

Kin Onn Chan ◽

Rafe M. Brown

Keyword(s):

Genetic Variation ◽

Gene Flow ◽

Isolation By Distance ◽

Variance Partitioning ◽

Population Bottlenecks ◽

Landscape Genomics ◽

Mountain Ranges ◽

Historical Factors ◽

Environmental Attributes ◽

Isolation By Environment

ABSTRACTThe interplay between environmental attributes and evolutionary processes can provide valuable insights into how biodiversity is generated, partitioned, and distributed. This study investigates the role of spatial, environmental, and historical factors that could potentially drive diversification and shape genetic variation in Malaysian torrent frogs. Torrent frogs are ecologically conserved, and we hypothesize that this could impose tight constraints on dispersal routes, gene flow, and consequently genetic structure. Moreover, levels of gene flow were shown to vary among populations from separate mountain ranges, indicating that genetic differentiation could be influenced by landscape features. Using genome-wide SNPs in conjunction with landscape variables derived from GIS, we performed distance-based redundancy analyses and variance partitioning to disentangle the effects of isolation-by-distance (IBD), isolation-by-environment (IBE), and isolation-by-colonization (IBC). Our results demonstrated that IBE, contributed minimally to genetic variation. Intraspecific population structure can be largely attributed to IBD, whereas interspecific diversification was primarily driven by IBC. We also detected two distinct population bottlenecks, indicating that speciation events were likely driven by vicariance or founder events.

Genetic differentiation of Sorbus torminalis in Eastern Europe as determined by microsatellite markers

Biologia ◽

10.2478/s11756-010-0082-y ◽

2010 ◽

Vol 65 (5) ◽

Cited By ~ 4

Author(s):

Veronika Kučerová ◽

Martin Honec ◽

Ladislav Paule ◽

Petar Zhelev ◽

Dušan Gömöry

Keyword(s):

Genetic Variation ◽

Gene Flow ◽

Genetic Differentiation ◽

Bayesian Methods ◽

Isolation By Distance ◽

General Pattern ◽

The Other ◽

Hand Model ◽

Sorbus Torminalis ◽

Nuclear Microsatellite

AbstractThe genetic variation in fourteen Sorbus torminalis (L.) Crantz. populations distributed over the eastern and south-eastern part of its range was studied using seven nuclear microsatellite loci. The differentiation level was relatively high (F ST = 0.228), as expected for a species with a fragmented range. The distance-based approach to the analysis of differentiation patterns (neighbour-joining tree based on pairwise coefficients of differentiation) did not reveal a clear geographical structure. On the other hand, model-based Bayesian methods (BAPS and STRUCTURE) gave geographically continuous clusters of populations. The occurrence of populations deviating strongly from the general pattern is attributed to founder effect. In spite of a generally high differentiation, a significant isolation-by-distance pattern was found, which might be a consequence of postglacial migration and gene flow among descendants of different refugia.

Genetic Relationships of Cory's Shearwater: Parentage, Mating Assortment, and Geographic Differentiation Revealed by DNA Fingerprinting

The Auk ◽

10.1093/auk/117.3.651 ◽

2000 ◽

Vol 117 (3) ◽

pp. 651-662 ◽

Cited By ~ 1

Author(s):

Corinne Rabouam ◽

Vincent Bretagnolle ◽

Yves Bigot ◽

Georges Periquet

Keyword(s):

Genetic Variation ◽

Genetic Structure ◽

Dna Fingerprinting ◽

Genetic Relatedness ◽

Isolation By Distance ◽

Genetic Relationships ◽

Cory’S Shearwater ◽

Genetic Structure Of Populations ◽

The Social ◽

Calonectris Diomedea

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.

Phylogeographic structure and gene flow of Himalayan snowcock (Tetraogallus himalayensis)

Animal Biology ◽

10.1163/157075610x523314 ◽

2010 ◽

Vol 60 (4) ◽

pp. 449-465

Author(s):

Wen Longying ◽

Zhang Lixun ◽

An Bei ◽

Luo Huaxing ◽

Liu Naifa ◽

...

Keyword(s):

Demographic History ◽

Phylogenetic Analyses ◽

Divergence Time ◽

Population Expansion ◽

Population History ◽

Tibet Plateau ◽

Phylogeographic Structure ◽

Mitochondrial Cytochrome B ◽

History Of ◽

Qinghai Tibet Plateau

AbstractWe have used phylogeographic methods to investigate the genetic structure and population history of the endangered Himalayan snowcock (Tetraogallus himalayensis) in northwestern China. The mitochondrial cytochrome b gene was sequenced of 102 individuals sampled throughout the distribution range. In total, we found 26 different haplotypes defined by 28 polymorphic sites. Phylogenetic analyses indicated that the samples were divided into two major haplogroups corresponding to one western and one eastern clade. The divergence time between these major clades was estimated to be approximately one million years. An analysis of molecular variance showed that 40% of the total genetic variability was found within local populations, 12% among populations within regional groups and 48% among groups. An analysis of the demographic history of the populations suggested that major expansions have occurred in the Himalayan snowcock populations and these correlate mainly with the first and the second largest glaciations during the Pleistocene. In addition, the data indicate that there was a population expansion of the Tianshan population during the uplift of the Qinghai-Tibet Plateau, approximately 2 million years ago.