scholarly journals Demographic history and population genetic analysis of Decapterus maruadsi from the northern South China Sea based on mitochondrial control region sequence

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7953 ◽  
Author(s):  
Su-Fang Niu ◽  
Ren-Xie Wu ◽  
Yun Zhai ◽  
Hao-Ran Zhang ◽  
Zhong-Lu Li ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Demographic History ◽  
Northern South China Sea ◽  
Mitochondrial Control Region ◽  
Pelagic Fish ◽  
Effective Population ◽  
Pleistocene Climate ◽  
Low Levels

Late Pleistocene climate oscillations are believed to have greatly influenced the distribution, population dynamics, and genetic variation of many marine organisms in the western Pacific. However, the impact of the late Pleistocene climate cycles on the demographic history and population genetics of pelagic fish in the northern South China Sea (SCS) remains largely unexplored. In this study, we explored the demographic history, genetic structure, and genetic diversity of Decapterus maruadsi, a typical pelagic fish, over most of its range in the northern SCS. A 828–832 bp fragment of mitochondrial control region were sequenced in 241 individuals from 11 locations. High haplotype diversity (0.905–0.980) and low nucleotide diversity (0.00269–0.00849) was detected, revealing low levels of genetic diversity. Demographic history analysis revealed a pattern of decline and subsequent rapid growth in the effective population size during deglaciation, which showed that D. maruadsi experienced recent demographic expansion after a period of low effective population size. Genetic diversity, genetic structure, and phylogenetic relationship analysis all demonstrated that no significant genetic differentiation existed among the populations, indicating that D. maruadsi was panmictic throughout the northern SCS. Periodic sea-level changes, fluctuation of the East Asian Monsoon, and Kuroshio variability were responsible for the population decline and expansion of D. maruadsi. The demographic history was the primary reason for the low levels of genetic diversity and the lack of significant genetic structure. The life history characteristics and ocean currents also had a strong correlation with the genetic homogeneity of D. maruadsi. However, the genetic structure of the population (genetic homogeneity) is inconsistent with biological characteristics (significant difference), which is an important reminder to identify and manage the D. maruadsi population carefully.

Conservation genetics of red pandas in the wild

2018 ◽  
Author(s):  
Yibo Hu ◽  
Dunwu Qi ◽  
Fuwen Wei
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Conservation Genetics ◽  
Human Activities ◽  
Population Genetic ◽  
Large Scale ◽  
Demographic History ◽  
Genetic Research ◽  
Phylogeographic Structure ◽  
Red Panda

The red panda is listed on the 2016 IUCN red list as Endangered. It is now distributed only in China, Myanmar, India, Bhutan and Nepal. Human activities such as poaching and large-scale deforestation have caused serious declines in this forest-dwelling species. Although its ecological research has made much progress in the past decades, only recently witnessed the population genetic research advances of this species. This chapter reviews the advances in wild red panda conservation genetics from non-invasive genetics, genetic diversity, phylogeographic structure, population genetic structure, demographic history, subspecies differentiation, to its conservation and management. It presents detailed estimates of genetic diversity, assesses the role of paleo-climate changes, human activities and landscape features in shaping the genetic structure and demographic history of red pandas, and discusses the implications of conservation genetics findings for effective genetic monitoring and conservation management.

scholarly journals The genetic structure of the European black pine (Pinus nigra Arnold) is shaped by its recent Holocene demographic history

2019 ◽  
Author(s):  
Guia Giovannelli ◽  
Caroline Scotti-Saintagne ◽  
Ivan Scotti ◽  
Anne Roig ◽  
Ilaria Spanu ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Population Genetic ◽  
Spatial Genetic Structure ◽  
Demographic History ◽  
Pinus Nigra ◽  
Forest Tree ◽  
Black Pine ◽  
Genetic Lineages ◽  
European Black Pine

AbstractFragmentation acting over geological times confers wide, biogeographical scale, genetic diversity patterns to species, through demographic and natural selection processes. To test the effects of historical fragmentation on the genetic diversity and differentiation of a major European forest tree and to resolve its demographic history, we describe and model its spatial genetic structure and gene genealogy. We then test which Pleistocene event, whether recent or ancient, could explain its widespread but patchy geographic distribution using population genetic data, environmental data and realistic demographic timed scenarios.The taxon of interest is a conifer forest tree, Pinus nigra (Arnold), the European black pine, whose populations are located in the mountains of southern Europe and North Africa, most frequently at mid-elevation. We used a set of different genetic markers, both neutral and potentially adaptive, and either bi-parentally or paternally inherited, and we sampled natural populations across the entire range of the species. We analysed the data using frequentist population genetic methods as well as Bayesian inference methods to calibrate realistic, demographic timed scenarios.Species with geographically fragmented distribution areas are expected to display strong among-population genetic differentiation and low within-population genetic diversity. Contrary to these expectations, we show that the current diversity of Pinus nigra and its weak genetic spatial structure are best explained as resulting from late Pleistocene or early Holocene fragmentation of one ancestral population into seven genetic lineages, which we found to be the main biogeographical contributors of the natural black pine forests of today. Gene flow among the different lineages is strong across forests and many current populations are admixed between lineages. We propose to modify the currently accepted international nomenclature made of five subspecies and name these seven lineages using regionally accepted subspecies-level names.HighlightsThe European black pine, Pinus nigra (Arnold), has a weak spatial genetic structure.Gene flow among populations is frequent and populations are often of admixed origin.Current genealogies result from recent, late Pleistocene or Holocene events.Seven modern genetic lineages emerged from divergence and demographic contractions.These seven lineages warrant a revision of subspecies taxonomic nomenclature.

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