scholarly journals Meta-analysis of northeast Atlantic marine taxa shows contrasting phylogeographic patterns following post-LGM expansions

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5684 ◽  
Author(s):  
Tom L. Jenkins ◽  
Rita Castilho ◽  
Jamie R. Stevens
Keyword(s):  
Genetic Diversity ◽  
Demographic History ◽  
Meta Analysis ◽  
Marine Species ◽  
Haplotype Network ◽  
Rapid Expansion ◽  
Evolutionary Processes ◽  
Comparative Phylogeography ◽  
Northeast Atlantic ◽  
Species Specific

Background Comparative phylogeography enables the study of historical and evolutionary processes that have contributed to shaping patterns of contemporary genetic diversity across co-distributed species. In this study, we explored genetic structure and historical demography in a range of coastal marine species across the northeast Atlantic to assess whether there are commonalities in phylogeographic patterns across taxa and to evaluate whether the timings of population expansions were linked to the Last Glacial Maximum (LGM). Methods A literature search was conducted using Web of Science. Search terms were chosen to maximise the inclusion of articles reporting on population structure and phylogeography from the northeast Atlantic; titles and abstracts were screened to identify suitable articles within the scope of this study. Given the proven utility of mtDNA in comparative phylogeography and the availability of these data in the public domain, a meta-analysis was conducted using published mtDNA gene sequences. A standardised methodology was implemented to ensure that the genealogy and demographic history of all mtDNA datasets were reanalysed in a consistent and directly comparable manner. Results Mitochondrial DNA datasets were built for 21 species. The meta-analysis revealed significant population differentiation in 16 species and four main types of haplotype network were found, with haplotypes in some species unique to specific geographical locations. A signal of rapid expansion was detected in 16 species, whereas five species showed evidence of a stable population size. Corrected mutation rates indicated that the majority of expansions were estimated to have occurred after the earliest estimate for the LGM (∼26.5 Kyr), while few expansions were estimated to have pre-dated the LGM. Conclusion This study suggests that post-LGM expansion appeared to be common in a range of marine taxa, supporting the concept of rapid expansions after the LGM as the ice sheets started to retreat. However, despite the commonality of expansion patterns in many of these taxa, phylogeographic patterns appear to differ in the species included in this study. This suggests that species-specific evolutionary processes, as well as historical events, have likely influenced the distribution of genetic diversity of marine taxa in the northeast Atlantic.

scholarly journals Does marine geospatial/environmental variation affect genetic variation? A meta-analysis

2021 ◽  
Author(s):  
◽  
Daniel Cárcamo
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New Zealand ◽  
Genetic Variability ◽  
Genetic Distance ◽  
Meta Analysis ◽  
Environmental Variation ◽  
Environmental Data ◽  
Seascape Genetics ◽  
Species Specific

<p>Genetic information is important to inform management and conservation. However, few studies have tested the relationship between genetic variation and geospatial/environmental variation across marine species. Here, I test two genetics-based ideas in evolutionary theory using data from 55 New Zealand coastal marine taxa. The Core-Periphery Hypothesis (CPH) states that populations at the centre of a species’ distribution exhibit greater genetic variability than populations at the periphery (the ‘normal’ model). Variants of this model include the ‘ramped north’ (greatest variation in the north), the ‘ramped south’ (greatest variation in the south), and the ‘abundant edge’ (greatest variation at the distributional edges, least variation at the centre). The Seascape Genetics Test (SGT) null hypothesis predicts no association between genetic variation and environmental variation. I conducted a meta-analysis of published/unpublished material on population genetic connectivity and diversity and marine environmental data to test both hypotheses. To assess the CPH, genetic data were fitted to four models (Normal, Ramped North, Ramped South, Abundant Edge). I also conducted a descriptive analysis between the genetic outcomes of the CPH and abundance records for a subset of species. The SGT involved GLM analyses using eleven geospatial/environmental variables and species-specific FST-ΦST (genetic distance) estimates plus a smaller subset of genetic diversity data. The CPH results showed that 55 of 249 tests (evaluating on average 2.9 ± 1.3 genetic indices in each of the 84 studies) fitted at least one of the four models: Ramped North (10%), Ramped South (8%), Normal (2%) and Abundant Edge (2.4%). Species-specific abundance records followed the same patterns detected by the CPH. These results indicate that edge populations (Ramped North, Ramped South, Abundant Edge) exhibit greater genetic variability than central populations amongst marine taxa from New Zealand, but that most taxa do not conform to any model (~78% of all tests were not statistically significant). For the seascape genetics multi-species analysis (comprising 498 individual tests), the FST-ΦST estimates (genetic distance estimates between pairs of populations) were mostly affected by four factors related to sea surface temperature. For genetic diversity indices the most significant predictors were latitude and longitude. Whilst different factors (e.g., physical oceanography, food availability, life-history traits and harvesting), either acting alone or acting synergistically, are likely to be important in explaining patterns of genetic diversity in New Zealand’s marine coastal species, my results indicate that variables including SST and to a lesser extent the geospatial variables (latitude and longitude) explain much of the variation in the genetic indices tested here.</p>

scholarly journals Genetic diversity and variation of seven Chinese grass shrimp (Palaemonetes sinensis) populations based on the mitochondrial COI gene

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yingying Zhao ◽  
Xiaochen Zhu ◽  
Ye Jiang ◽  
Zhi Li ◽  
Xin Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Demographic History ◽  
Haplotype Diversity ◽  
Grass Shrimp ◽  
Haplotype Network ◽  
Coi Gene ◽  
Wild Populations ◽  
Important Species ◽  
Network Analyses ◽  
Maximum Variation

Abstract Background Chinese grass shrimp (Palaemonetes sinensis) is an important species widely distributed throughout China, which is ecologically relevant and possesses ornamental and economic value. These organisms have experienced a sharp decline in population due to overfishing. Therefore interest in P. sinensis aquaculture has risen in an effort to alleviate fishing pressure on wild populations. Therefore, we investigated the genetic diversity and variation of P. sinensis to verify the accuracy of previous research results, as well as to assess the risk of diversity decline in wild populations and provide data for artificial breeding. Methods Palaemonetes sinensis specimens from seven locations were collected and their genetic variability was assessed based on mitochondrial COI gene segments. DNA sequence polymorphisms for each population were estimated using DNASP 6.12. The demographic history and genetic variation were evaluated using Arlequin 3.11. At last, the pairwise genetic distance (Ds) values and dendrograms were constructed with the MEGA 11 software package. Results Our study obtained sequences from 325 individuals, and 41 haplotypes were identified among the populations. The haplotype diversity (Hd) and nucleotide diversity (π) indices ranged from 0.244 ± 0.083 to 0.790 ± 0.048 and from 0.0004 ± 0.0001 to 0.0028 ± 0.0006, respectively. Haplotype network analyses identified haplotype Hap_1 as a potential maternal ancestral haplotype for the studied populations. AMOVA results indicated that genetic variations mainly occurred within populations (73.07%). Moreover, according to the maximum variation among groups (FCT), analysis of molecular variance using the optimal two-group scheme indicated that the maximum variation occurred among groups (53.36%). Neutrality and mismatch distribution tests suggested that P. sinensis underwent a recent population expansion. Consistent with the SAMOVA analysis and haplotype network analyses, the Ds and FST between the population pairs indicated that the JN population was distinctive from the others. Conclusions Our study conducted a comprehensive characterization of seven wild P. sinensis populations, and our findings elucidated highly significant differences within populations. The JN population was differentiated from the other six populations, as a result of long-term geographical separation. Overall, the present study provided a valuable basis for the management of genetic resources and a better understanding of the ecology and evolution of this species.

scholarly journals Does marine geospatial/environmental variation affect genetic variation? A meta-analysis

2021 ◽  
Author(s):  
◽  
Daniel Cárcamo
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
New Zealand ◽  
Genetic Variability ◽  
Genetic Distance ◽  
Meta Analysis ◽  
Environmental Variation ◽  
Environmental Data ◽  
Seascape Genetics ◽  
Species Specific

<p>Genetic information is important to inform management and conservation. However, few studies have tested the relationship between genetic variation and geospatial/environmental variation across marine species. Here, I test two genetics-based ideas in evolutionary theory using data from 55 New Zealand coastal marine taxa. The Core-Periphery Hypothesis (CPH) states that populations at the centre of a species’ distribution exhibit greater genetic variability than populations at the periphery (the ‘normal’ model). Variants of this model include the ‘ramped north’ (greatest variation in the north), the ‘ramped south’ (greatest variation in the south), and the ‘abundant edge’ (greatest variation at the distributional edges, least variation at the centre). The Seascape Genetics Test (SGT) null hypothesis predicts no association between genetic variation and environmental variation. I conducted a meta-analysis of published/unpublished material on population genetic connectivity and diversity and marine environmental data to test both hypotheses. To assess the CPH, genetic data were fitted to four models (Normal, Ramped North, Ramped South, Abundant Edge). I also conducted a descriptive analysis between the genetic outcomes of the CPH and abundance records for a subset of species. The SGT involved GLM analyses using eleven geospatial/environmental variables and species-specific FST-ΦST (genetic distance) estimates plus a smaller subset of genetic diversity data. The CPH results showed that 55 of 249 tests (evaluating on average 2.9 ± 1.3 genetic indices in each of the 84 studies) fitted at least one of the four models: Ramped North (10%), Ramped South (8%), Normal (2%) and Abundant Edge (2.4%). Species-specific abundance records followed the same patterns detected by the CPH. These results indicate that edge populations (Ramped North, Ramped South, Abundant Edge) exhibit greater genetic variability than central populations amongst marine taxa from New Zealand, but that most taxa do not conform to any model (~78% of all tests were not statistically significant). For the seascape genetics multi-species analysis (comprising 498 individual tests), the FST-ΦST estimates (genetic distance estimates between pairs of populations) were mostly affected by four factors related to sea surface temperature. For genetic diversity indices the most significant predictors were latitude and longitude. Whilst different factors (e.g., physical oceanography, food availability, life-history traits and harvesting), either acting alone or acting synergistically, are likely to be important in explaining patterns of genetic diversity in New Zealand’s marine coastal species, my results indicate that variables including SST and to a lesser extent the geospatial variables (latitude and longitude) explain much of the variation in the genetic indices tested here.</p>

scholarly journals Genetic Diversity and Demographic History of the Shaggy Soft-Haired Mouse Abrothrix hirta (Cricetidae; Abrotrichini)

2021 ◽  
Vol 12 ◽  
Author(s):  
Lourdes Valdez ◽  
Guillermo D’Elía
Keyword(s):  
Genetic Diversity ◽  
Demographic History ◽  
Population Expansion ◽  
Principal Component ◽  
Tierra Del Fuego ◽  
Local Fauna ◽  
Recent Population Expansion ◽  
Genetic Groups ◽  
History Of ◽  
Species Specific

Genetic information on species can inform decision making regarding conservation of biodiversity since the response of organisms to changing environments depend, in part, on their genetic makeup. Territories of central-southern Chile and Argentina have undergone a varying degree of impact during the Quaternary, where the response of local fauna and flora was rather species-specific. Here, we focus on the sigmodontine rodent Abrothrix hirta, distributed from 35° S in Chile and Argentina to northern Tierra del Fuego. Based on 119,226 transcriptome-derived SNP loci from 46 individuals of A. hirta, we described the geographic distribution of the genetic diversity of this species using a maximum likelihood tree, principal component and admixture analyses. We also addressed the demographic history of the main intraspecific lineages of A. hirta using GADMA. We found that A. hirta exhibited four allopatric intraspecific lineages. Three main genetic groups were identified by a Principal Component Analysis and by Ancestry analysis. The demographic history of A. hirta was characterized by recent population stability for populations at the northernmost part of the range, while southern populations experienced a recent population expansion.

Genetic variability and demographic history of Heliothis virescens (Lepidoptera: Noctuidae) populations from Brazil inferred by mtDNA sequences

2011 ◽  
Vol 102 (3) ◽  
pp. 333-343 ◽  
Author(s):  
K.C. Albernaz ◽  
K.L. Silva-Brandão ◽  
P. Fresia ◽  
F.L. Cônsoli ◽  
C. Omoto
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Heliothis Virescens ◽  
Demographic History ◽  
Haplotype Diversity ◽  
Low Frequency ◽  
Haplotype Network ◽  
Demographic Expansion ◽  
Significant Genetic Structure ◽  
History Of

AbstractIntra- and inter-population genetic variability and the demographic history of Heliothis virescens (F.) populations were evaluated by using mtDNA markers (coxI, coxII and nad6) with samples from the major cotton- and soybean-producing regions in Brazil in the growing seasons 2007/08, 2008/09 and 2009/10. AMOVA indicated low and non-significant genetic structure, regardless of geographical scale, growing season or crop, with most of genetic variation occurring within populations. Clustering analyzes also indicated low genetic differentiation. The haplotype network obtained with combined datasets resulted in 35 haplotypes, with 28 exclusive occurrences, four of them sampled only from soybean fields. The minimum spanning network showed star-shaped structures typical of populations that underwent a recent demographic expansion. The recent expansion was supported by other demographic analyzes, such as the Bayesian skyline plot, the unimodal distribution of paired differences among mitochondrial sequences, and negative and significant values of neutrality tests for the Tajima's D and Fu's FS parameters. In addition, high values of haplotype diversity (Ĥ) and low values of nucleotide diversity (π), combined with a high number of low frequency haplotypes and values of θπ<θW, suggested a recent demographic expansion of H. virescens populations in Brazil. This demographic event could be responsible for the low genetic structure currently found; however, haplotypes present uniquely at the same geographic regions and from one specific host plant suggest an initial differentiation among H. virescens populations within Brazil.

scholarly journals Influence of Quaternary environmental changes on mole populations inferred from mitochondrial sequences and evolutionary rate estimation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Azusa Nakamoto ◽  
Masashi Harada ◽  
Reiko Mitsuhashi ◽  
Kimiyuki Tsuchiya ◽  
Alexey P. Kryukov ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Environmental Changes ◽  
Late Quaternary ◽  
Population Expansion ◽  
Rapid Expansion ◽  
Dependent Manner ◽  
Distribution Analysis ◽  
Land Bridge ◽  
Mismatch Distribution Analysis ◽  
Expansion Event

AbstractQuaternary environmental changes fundamentally influenced the genetic diversity of temperate-zone terrestrial animals, including those in the Japanese Archipelago. The genetic diversity of present-day populations is taxon- and region-specific, but its determinants are poorly understood. Here, we analyzed cytochrome b gene (Cytb) sequences (1140 bp) of mitochondrial DNA (mtDNA) to elucidate the factors determining the genetic variation in three species of large moles: Mogera imaizumii and Mogera wogura, which occur in central and southern mainland Japan (Honshu, Shikoku, and Kyushu), and Mogera robusta, which occurs on the nearby Asian continent. Network construction with the Cytb sequences revealed 10 star-shaped clusters with apparent geographic affinity. Mismatch distribution analysis showed that modes of pairwise nucleotide differences (τ values) were grouped into five classes in terms of the level, implying the occurrence of five stages for rapid expansion. It is conceivable that severe cold periods and subsequent warm periods during the late Quaternary were responsible for the population expansion events. The first and third oldest events included island-derived haplotypes, indicative of the involvement of land bridge formation between remote islands, hence suggesting an association of the ends of the penultimate (PGM, ca. 130,000 years ago) and last (LGM, ca. 15,000 years ago) glacial maxima, respectively. Since the third event was followed by the fourth, it is plausible that the termination of the Younger Dryas and subsequent abrupt warming ca. 11,500 years ago facilitated the fourth expansion event. The second event most likely corresponded to early marine isotope stage (MIS) 3 (ca. 53,000 years ago) when the glaciation and subsequent warming period were predicted to have influenced biodiversity. Utilization of the critical times of 130,000, 53,000, 15,000, and 11,500 years ago as calibration points yielded evolutionary rates of 0.03, 0.045, 0.10 and 0.10 substitutions/site/million years, respectively, showing a time-dependent manner whose pattern was similar to that seen in small rodents reported in our previous studies. The age of the fifth expansion event was calculated to be 5800 years ago with a rate of 0.10 substitutions/site/million years ago during the mid-Holocene, suggestive of the influence of humans or other unspecified reasons, such as the Jomon marine transgression.

scholarly journals Functional genetic diversity in an exploited marine species and its relevance to fisheries management

2021 ◽  
Vol 288 (1945) ◽  
pp. 20202398
Author(s):  
Eleni L. Petrou ◽  
Angela P. Fuentes-Pardo ◽  
Luke A. Rogers ◽  
Melissa Orobko ◽  
Carolyn Tarpey ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Isolation By Distance ◽  
Chromosomal Rearrangements ◽  
High Mobility ◽  
Marine Species ◽  
Clupea Harengus ◽  
Pacific Herring ◽  
Reproductive Timing ◽  
Cultural Significance ◽  
Ecological Processes

The timing of reproduction influences key evolutionary and ecological processes in wild populations. Variation in reproductive timing may be an especially important evolutionary driver in the marine environment, where the high mobility of many species and few physical barriers to migration provide limited opportunities for spatial divergence to arise. Using genomic data collected from spawning aggregations of Pacific herring ( Clupea pallasii ) across 1600 km of coastline, we show that reproductive timing drives population structure in these pelagic fish. Within a specific spawning season, we observed isolation by distance, indicating that gene flow is also geographically limited over our study area. These results emphasize the importance of considering both seasonal and spatial variation in spawning when delineating management units for herring. On several chromosomes, we detected linkage disequilibrium extending over multiple Mb, suggesting the presence of chromosomal rearrangements. Spawning phenology was highly correlated with polymorphisms in several genes, in particular SYNE2 , which influences the development of retinal photoreceptors in vertebrates. SYNE2 is probably within a chromosomal rearrangement in Pacific herring and is also associated with spawn timing in Atlantic herring ( Clupea harengus ). The observed genetic diversity probably underlies resource waves provided by spawning herring. Given the ecological, economic and cultural significance of herring, our results support that conserving intraspecific genetic diversity is important for maintaining current and future ecosystem processes.

scholarly journals Demographic history shaped geographical patterns of deleterious mutation load in a broadly distributed Pacific Salmon

2019 ◽  
Author(s):  
Quentin Rougemont ◽  
Jean-Sébastien Moore ◽  
Thibault Leroy ◽  
Eric Normandeau ◽  
Eric B. Rondeau ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Coho Salmon ◽  
Pacific Salmon ◽  
Demographic History ◽  
Glacial Refugium ◽  
Human Populations ◽  
Deleterious Mutations ◽  
Effective Population ◽  
Geographical Patterns ◽  
Genome Wide Data

AbstractA thorough reconstruction of historical processes is essential for a comprehensive understanding the mechanisms shaping patterns of genetic diversity. Indeed, past and current conditions influencing effective population size have important evolutionary implications for the efficacy of selection, increased accumulation of deleterious mutations, and loss of adaptive potential. Here, we gather extensive genome-wide data that represent the extant diversity of the Coho salmon (Oncorhynchus kisutch) to address two objectives. We demonstrate that a single glacial refugium is the source of most of the present-day genetic diversity, with detectable inputs from a putative secondary micro-refugium. We found statistical support for a scenario whereby ancestral populations located south of the ice sheets expanded in postglacial time, swamping out most of the diversity from other putative micro-refugia. Demographic inferences revealed that genetic diversity was also affected by linked selection in large parts of the genome. Moreover, we demonstrate that the recent demographic history of this species generated regional differences in the load of deleterious mutations among populations, a finding that mirrors recent results from human populations and provides increased support for models of expansion load. We propose that insights from these historical inferences should be better integrated in conservation planning of wild organisms, which currently focuses largely on neutral genetic diversity and local adaptation, with the role of potentially maladaptive variation being generally ignored.

scholarly journals Comparative Population Genetics of Two Korean Aedes Mosquito Species with Vector Potential based on Mitochondrial DNA

2021 ◽  
Author(s):  
Jiyeong Shin ◽  
Jongwoo Jung
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Vector Control ◽  
Endemic Species ◽  
Korean Peninsula ◽  
Mismatch Distribution ◽  
Mosquito Species ◽  
Mitochondrial Genes ◽  
Rapid Expansion ◽  
Number Of Individuals

Abstract Background: Mosquitoes of the genus Aedes are important invasive species contributing to the spread of chikungunya, dengue fever, yellow fever, Zika virus, and other dangerous vector-borne diseases. Aedes albopictus is native to southeast Asia with rapid expansion due to human activity, showing a wide distribution in the Korean peninsula. Aedes flavopictus is considered to be native to East Asia with a broad distribution in the region, including in the Korean peninsula. Gaining a better understanding of the genetic diversity of these species is critical for establishing strategies for disease prevention and vector control. Methods: We obtained DNA from 148 specimens of Ae. albopictus and 166 specimens of Ae. flavopictus in Korea, and amplified two mitochondrial genes (COI and ND5) to compare the genetic diversity and structure of the two species.Results: We obtained a 658-bp sequence of COI and a 423-bp sequence of ND5 from the two mosquito species. We found low diversity and an insignificant population genetic structure in Ae. albopictus, and high diversity and an insignificant structure in Ae. flavopictus for these two mitochondrial genes. Ae. albopictus had less haplotypes with respect to the number of individuals, and a slight mismatch distribution was confirmed. By contrast, Ae. flavopictus had a large number of haplotypes compared with the number of individuals, and a large unimodal-type mismatch distribution was confirmed. Although the genetic structure of both species was insignificant, Ae. flavopictus exhibited higher genetic diversity than Ae. albopictus.Conclusions: Ae. albopictus appears to be an introduced species, whereas Ae. flavopictus is an endemic species to the Korean peninsula, and the difference in genetic diversity between the two species is related to their adaptability and introduction history. As an endemic species, Ae. flavopictus is likely to have a larger population size than expected. Further studies on the genetic structure and diversity of these two mosquito species will provide useful data for vector control.

scholarly journals Genetic diversity of SARS-CoV-2 in South America: demographic history and structuration signals

2021 ◽  
Author(s):  
Sindy P. Buitrago ◽  
Diego Garzón-Ospina
Keyword(s):  
Genetic Diversity ◽  
South America ◽  
Demographic History
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