scholarly journals Introductory Chapter: Genetic Variation - The Source of Biological Diversity

2021 ◽  
Author(s):  
Rafael Trindade Maia ◽  
Magnólia de Araújo Campos
Keyword(s):  
Genetic Variation ◽  
Biological Diversity

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

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5733 ◽  
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.

scholarly journals Uplift and erosion of genomic islands with standing genetic variation

2016 ◽  
Author(s):  
Tyler D. Hether
Keyword(s):  
Genetic Variation ◽  
Genetic Differentiation ◽  
Biological Diversity ◽  
Empirical Studies ◽  
Theoretical Models ◽  
Divergent Selection ◽  
Genomic Islands ◽  
Island Formation ◽  
Standing Variation ◽  
Uplift And Erosion

AbstractDetails of the processes that generate biological diversity have long been of interest to evolutionary biologists. A common theme in nature is diversification via divergent selection with gene flow. Empirical studies on this topic find variable genetic differentiation throughout the genome, that genetic differentiation is non-randomly distributed, and that loci of adaptive significance are often found clustered together within “genomic islands of divergence”. Theoretical models based on new mutations show how these genomic islands can arise and grow as a result of a complex interaction of various evolutionary and genic processes. In the current study, I ask if such genomic islands can alternatively arise from divergent selection from standing genetic variation and I tested this using a simple two locus model of selection. There are numerous ways in which standing genetic variation can be partitioned (e.g., between alleles, between loci, and between populations) and I tested which of these scenarios can give rise to an island pattern compared to no genomic differentiation or complete genomic differentiation. I found that divergent selection, even without reciprocal gene exchange between populations, following a bout of admixture can relatively quickly produce an island pattern. Moreover, I found two pathways in which islands can form from divergence from standing variation: 1) through the build up of islands and 2) through the breakdown of larger, genome-wide differentiation. Lastly, similar to new mutation theory, I found that the frequency of recombination is an important determinant of island formation from standing genetic variation such that mating behavior of a species (e.g., facultative or obligate sexual) can impact the likelihood of island formation.

Introduction

2020 ◽  
pp. 7-24
Author(s):  
Nicolas Langlitz
Keyword(s):  
Cultural Diversity ◽  
Human Nature ◽  
Nonhuman Primates ◽  
Biological Diversity ◽  
Homo Sapiens ◽  
Modern Humans ◽  
Cultural Primatology ◽  
The 1950S

This introductory chapter provides a background of the ensuing controversy over chimpanzee culture. Japanese and Euro-American primatologists have come to question whether humans are the only primates capable of culture — that is, whether culture amounts to human nature. In the 1950s, Japanese primatologists around Kinji Imanishi proposed to attribute “subhuman culture” — or kaluchua, as they called it — to nonhuman primates. In the course of the 1970s and 1980s, a growing number of European and American primatologists and evolutionary anthropologists chimed in with Japanese anthropomorphism and wondered how unique the cultural nature of Homo sapiens really was. Just as cultural anthropologists have struggled to account for the loss of cultural diversity during five centuries of Euro-American domination (currently on the wane), cultural primatology is now confronted with the question of how to make sense of the eradication of nonhuman cultural and biological diversity in light of modern humans' savage success.

scholarly journals High genetic diversity and presence of genetic structure characterise the Corso-Sardinian endemics Ruta corsica and Ruta lamarmorae (Rutaceae)

2018 ◽  
Author(s):  
Marilena Meloni ◽  
Caterina Angela Dettori ◽  
Andrea Reid ◽  
Gianluigi Bacchetta ◽  
Laetitia Hugot ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Biological Diversity ◽  
Taxonomic Status ◽  
Single Species ◽  
Dispersal Ability ◽  
Separate Species ◽  
High Genetic Diversity ◽  
History Of

SummaryCorsica and Sardinia form one of the ten areas with highest biodiversity in the Mediterranean and are considered one of the priority regions for conservation in Europe. In order to preserve the high levels of endemism and biological diversity at different hierarchical levels, knowledge of the evolutionary history and current genetic structure of Corso-Sardinian endemics is instrumental. Microsatellite markers were newly developed and used to study the genetic structure and taxonomic status of Ruta corsica and Ruta lamarmorae, rare endemics of Corsica and Sardinia, respectively, and previously considered a single species. Our analyses identified high levels of genetic variation within each species (P=0.883, He=0.543 for R. corsica; P=0.972, He=0.627 for R. lamarmorae). Intrinsic traits of the species (hermaphroditism, proterandry and polyploidy) and island-dependent factors (i.e. age, origin and history of the islands) might explain the detected high levels of genetic variation. We discovered differentiation between R. corsica and R. lamarmorae, and genetic structure within each species, which are consistent with the observation of low dispersal ability for both species. Our genetic results support the recent taxonomic classification of R. corsica and R. lamarmorae as separate species and suggest that they diverge at only few loci. One R. corsica population (SA) strongly differed from all other studied populations and appeared to be the product of hybridization between the two species in STRUCTURE analyses. Our results provide important insights for the conservation of the two rare endemics. Further genetic analyses are recommended for R. lamarmorae and for population SA (R. corsica).

Science of conservation for populations at risk

2007 ◽  
Vol 2007 ◽  
pp. 252-252
Author(s):  
J. A. Woolliams
Keyword(s):  
Quality Of Life ◽  
At Risk ◽  
Genetic Variation ◽  
Biological Diversity ◽  
Convention On Biological Diversity ◽  
Visual Diversity ◽  
Populations At Risk ◽  
Scientific Justification

Conservation is a long term activity, and the objectives of the activity must be clear and justified for it to be sustained in the long-term. Whilst the obligations for conservation-related activities are clearly set out in the Convention on Biological Diversity (“Rio” convention or CBD), the scale of activities will depend on the scope and quality of the case. A market-led justification for conservation of livestock is fraught with difficulty since if markets supported the full scope of existing genetic variation there would be no need for conservation. This does not imply that a long-term economic case cannot be made, but it does focus the arguments onto the future importance of the range of livestock breeds. Therefore beyond the benefits of visual diversity on the quality of life, there is a need for evaluating the scientific justification for conserving livestock breeds.

scholarly journals Genetic Diversity of Plant Species in Glacier National Park: Implications for Management

1990 ◽  
Vol 14 ◽  
pp. 55-58
Author(s):  
Thomas Mitchell-Olds
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
National Park ◽  
Biological Diversity ◽  
Management Strategies ◽  
Natural Populations ◽  
Glacier National Park ◽  
Isozyme Electrophoresis ◽  
Quantitative Genetic ◽  
Local Environments

Glacier National Park (GNP) is responsible for the management and preservation of biological diversity in the natural populations of plants and animals occurring within its boundaries. Information on existing levels of genetic variation within and among populations is a prerequisite for developing management strategies to maintain genetic diversity and to perform revegetation activities. We are using two methods to assess levels of genetic diversity and differentiation among populations: quantitative genetic analysis and isozyme (electrophoresis) analysis. To examine whether patterns of genetic variation and adaptation to local environments require that sites be revegetated with plants collected from nearby natural populations, or alternatively, whether transplants could be obtained from other sources; we are focussing on three experimental areas: 1. quantitative genetics; 2. electrophoresis, and 3. natural selection.

scholarly journals BioJS-HGV Viewer: Genetic Variation Visualizer

2015 ◽  
Author(s):  
Saket Choudhary ◽  
Leyla Garcia ◽  
Andrew Nightingale ◽  
Maria-Jesus Martin
Keyword(s):  
Genetic Variation ◽  
Genetic Variants ◽  
Biological Diversity ◽  
Source Code ◽  
Disease States ◽  
Levels Of Detail ◽  
Key Driver ◽  
User Friendly ◽  
Different Sources ◽  
Different Levels

Studying the pattern of genetic variants is a primary step in deciphering the basis of biological diversity, identifying key `driver variants' that affect disease states and evolution of a species. Catalogs of genetic variants contain vast numbers of variants and are growing at an exponential rate, but lack an interactive exploratory interface. We present BioJS-HGV Viewer, a BioJS component to represent and visualize genetic variants pooled from different sources. The tool displays sequences and variants at different levels of detail, facilitating representation of variant sites and annotations in a user friendly and interactive manner. Source code for BioJS-HGV Viewer is available at: https://github.com/saketkc/biojs-genetic-variation-viewer A demo is available at: http://saketkc.github.io/biojs-genetic-variation-viewer

scholarly journals Allozyme Based Genetic Variation between Hatchery and Natural Populations of Sahar (Tor putitora)

2015 ◽  
Vol 26 ◽  
pp. 212-223
Author(s):  
Suresh K Wagle ◽  
Neeta Pradhan ◽  
Tek B Gurung ◽  
Jay D Bista
Keyword(s):  
Genetic Variation ◽  
First Generation ◽  
Biological Diversity ◽  
Anthropogenic Activities ◽  
Natural Populations ◽  
Effective Population ◽  
Polymorphic Loci ◽  
Tor Putitora ◽  
Two Generations ◽  
Hardy Weinberg Equilibrium

Sahar (Tor putitora) formed a substantial natural fishery in the major riverine and lacustrine ecosystem of Nepal. Biological diversity of this species is being threatened by various anthropogenic activities. In view of the conservational value and the aquaculture potential of T. putitora, significant development in artificial propagation of this species has been achieved. The successful hatchery production of T. putitora brought to the forefront problematic questions regarding genetic variation of the hatchery stocks. A study was, therefore, conducted to determine the genetic variability within and between hatchery stocks and their wild counterparts of T. putitora using allozyme markers.Analyses of seven enzyme systems resuled in 11 loci being resolved from lake population and two consecutive generations of hatchery populations of T. putitora. Based on five polymorphic loci, all populations had percentage polymorphic loci 45.45. Significant reduction (P<0.01) in number of alleles per locus was evident in hatchery populations (1.45 ±0.181) compared to lake population (1.72 ±0.90). Loss of rear alleles, EST-2*74, IDH*70 and GDH*33 occurred in both of the hatchery populations which were present in wild counterparts- the lake population. All populations under study conform to the Hardy-Weinberg equilibrium at the 1% level. Although not significant (P>0.05), observed heterozygosity increased in first generation of hatchery population (Ho= 0.181 ±0.233) compared to natural population (Ho=0.179±0.221). The Ho of second generation of hatchery population was lowest (0.119 ±0.143) among the populations studied. Loss of rare alleles from the two generations of hatchery population, while these alleles were present in corresponding natural populations suggested the founders (20-30 individuals) of the hatchery populations probably represented bottlenecks to very small effective population size (Ne).J. Nat. Hist. Mus. Vol. 26, 2012: 212-223  

Letters. Biological diversity

1983 ◽  
Vol 17 (4) ◽  
pp. 160-160
Author(s):  
David Whitman
Keyword(s):  
Biological Diversity
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