Genetic variation in the widespread Embothrium coccineum (Proteaceae) endemic to Patagonia: effects of phylogeny and historical events

2007 ◽  
Vol 55 (8) ◽  
pp. 809 ◽  
Author(s):  
Cintia P. Souto ◽  
Andrea C. Premoli
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Life History Traits ◽  
Glacial Refugia ◽  
Genetic Distances ◽  
Species Level ◽  
Historical Events ◽  
Adult Trees ◽  
Cold Tolerant ◽  
Parsimony Trees

Allozyme electrophoresis was used to measure and compare, with other members of the Proteaceae, levels and distribution of genetic diversity in Embothrium coccineum J.R.Forst., a widespread outcrossing species endemic of Andean Patagonian forests. We analysed variation at the species level by sampling 34 populations along its entire range of ~20° latitude. We tested the hypothesis of multiple Pleistocene refugia by phylogeographic methods. We resolved 16 isozyme loci assayed in 934 adult trees. At the species level, total genetic diversity (HT = 0.220) was similar to that of other outcrossed and widespread plant species. Genetic parameters (NA, PSS, HE) were not statistically different from other outcrossed but mostly range-restricted Proteaceae, reflecting a strong phylogenetic imprinting for species sharing life-history traits. Populations are genetically divergent among each other (FST = 0.202). The low correlation between geographic and genetic distances suggests separate histories, i.e. multiple glacial refugia for the cold-tolerant E. coccineum. Phylogeographic trees produced different topologies, although maximum likelihood and parsimony trees shared some elements. Both trees suggest a northern and central clade, and then a separate southern clade. Current processes such as gene flow and selection confound the historic signal. These results seem in contrast to many of the northern hemisphere post-glacial phylogeographic reconstructions which show clear historical tracks of northern range expansion from southern refugia. The present study highlights the importance of phylogenetic imprinting, life-history traits and historical events driving genetic diversity patterns in this widespread Proteaceae from southern South America.

Genetic diversity of three Aegla species (Decapoda, Anomura) revealed by AFLP and mtDNA markers

Crustaceana ◽  
2019 ◽  
Vol 92 (4) ◽  
pp. 445-462
Author(s):  
Bianca L. Zimmermann ◽  
Jober V. De Vargas Machado ◽  
Sandro Santos ◽  
Marlise L. Bartholomei-Santos
Keyword(s):  
Genetic Diversity ◽  
Distinct Species ◽  
Genetic Distances ◽  
Species Level ◽  
Taxonomic Resolution ◽  
Similar Species ◽  
Southern Brazil ◽  
Low Levels ◽  
Management And Conservation ◽  
Mtdna Markers

Abstract Representatives of the genus Aegla present a conserved morphology; thus, the increased use of molecular markers has raised many taxonomic issues. We used AFLP and mtDNA to investigate the genetic differentiation and phylogenetic relationships of morphologically similar species with overlapping distribution areas in southern Brazil: A. georginae, A. ludwigi, and A. platensis. While A. platensis is widely distributed, the critically endangered A. georginae and A. ludwigi have limited distributions. Although both markers showed populations with low levels of genetic variability, they differed markedly in revealing relationships between populations; according to AFLP, the genetic distances between A. platensis populations were as high as those between distinct species, a result not observed when considering mtDNA data. We emphasize that the use of multiple lines of evidence is necessary for defining correct levels of genetic diversity and a good species-level taxonomic resolution. Such features are essential for the management and conservation of Aegla species.

scholarly journals Estructura genética de poblaciones de Eriocaulon bilobatum (Eriocaulaceae): una especie amenazada de humedades temporales

2019 ◽  
Vol 85 ◽  
pp. 81
Author(s):  
Fabiola Magallán Hernández ◽  
Mahinda Martínez ◽  
Luis Hernández Sandoval ◽  
Ken Oyama
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Genetic Structure ◽  
Gel Electrophoresis ◽  
Life History Traits ◽  
Aquatic Environments ◽  
Starch Gel Electrophoresis ◽  
Temporary Wetlands ◽  
Sexual And Asexual Reproduction ◽  
Starch Gel

<em>Eriocaulon bilobatum</em> is an aquatic species that inhabits temporary wetlands in central Mexico. It is annual, herbaceous, emergent, with sexual and asexual reproduction, monoecious and insect pollinated. It is a rare and vulnerable species due to its endangered habitats. The objectives of this study were to determine the diversity and genetic structure of <em>E. bilobatum </em> and to know if there is a correlation with genetic diversity and its ecological and life history traits. Using horizontal starch-gel electrophoresis, we screened 160 individuals from four populations. <em>E. bilobatum</em> has a higher genetic diversity (A=2.32, Ae=1.31, P=69.65, Ho=0.134, He=0.197, HT=0.221) than species with similar ecological and life history traits, moderate levels of inbreeding (FIS = 0.312) and low genetic differentiation among populations (FST = 0.053 y GST = 0.048). Its diversity and genetic structure are determined by the mating system and life history traits, more than by inhabiting aquatic environments.

scholarly journals Evolution and seed dormancy shape plant genotypic structure through a successional cycle

2021 ◽  
Vol 118 (34) ◽  
pp. e2026212118
Author(s):  
Anurag A. Agrawal ◽  
Amy P. Hastings ◽  
John L. Maron
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Environmental Change ◽  
Seed Dormancy ◽  
Life History Traits ◽  
Rapid Evolution ◽  
Insect Herbivory ◽  
Oenothera Biennis ◽  
The Face ◽  
The Impact

Dormancy has repeatedly evolved in plants, animals, and microbes and is hypothesized to facilitate persistence in the face of environmental change. Yet previous experiments have not tracked demography and trait evolution spanning a full successional cycle to ask whether early bouts of natural selection are later reinforced or erased during periods of population dormancy. In addition, it is unclear how well short-term measures of fitness predict long-term genotypic success for species with dormancy. Here, we address these issues using experimental field populations of the plant Oenothera biennis, which evolved over five generations in plots exposed to or protected from insect herbivory. While populations existed above ground, there was rapid evolution of defensive and life-history traits, but populations lost genetic diversity and crashed as succession proceeded. After >5 y of seed dormancy, we triggered germination from the seedbank and genotyped >3,000 colonizers. Resurrected populations showed restored genetic diversity that reduced earlier responses to selection and pushed population phenotypes toward the starting conditions of a decade earlier. Nonetheless, four defense and life-history traits remained differentiated in populations with insect suppression compared with controls. These findings capture key missing elements of evolution during ecological cycles and demonstrate the impact of dormancy on future evolutionary responses to environmental change.

scholarly journals Genetic and phenotypic changes in an Atlantic salmon population supplemented with non-local individuals: a longitudinal study over 21 years

2015 ◽  
Vol 282 (1802) ◽  
pp. 20142765 ◽  
Author(s):  
Sabrina Le Cam ◽  
Charles Perrier ◽  
Anne-Laure Besnard ◽  
Louis Bernatchez ◽  
Guillaume Evanno
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Atlantic Salmon ◽  
Life History Traits ◽  
Genetic Admixture ◽  
Phenotypic Traits ◽  
Source Population ◽  
Wild Populations ◽  
Non Local ◽  
Source Populations

While introductions and supplementations using non-native and potentially domesticated individuals may have dramatic evolutionary effects on wild populations, few studies documented the evolution of genetic diversity and life-history traits in supplemented populations. Here, we investigated year-to-year changes from 1989 to 2009 in genetic admixture at 15 microsatellite loci and in phenotypic traits in an Atlantic salmon ( Salmo salar ) population stocked during the first decade of this period with two genetically and phenotypically distinct source populations. We detected a pattern of temporally increasing introgressive hybridization between the stocked population and both source populations. The proportion of fish returning to the river after a single winter at sea ( versus several ones) was higher in fish assigned to the main source population than in local individuals. Moreover, during the first decade of the study, both single-sea-winter and multi-sea-winter (MSW) fish assigned to the main source population were smaller than local fish. During the second decade of the study, MSW fish defined as hybrids were lighter and smaller than fish from parental populations, suggesting outbreeding depression. Overall, this study suggests that supplementation with non-local individuals may alter not only the genetic diversity of wild populations but also life-history traits of adaptive significance.

scholarly journals Life history traits and dispersal shape neutral genetic diversity in metapopulations

2021 ◽  
Author(s):  
Jimmy Garnier ◽  
Pierre Lafontaine
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Life History Traits ◽  
Global Scale ◽  
Local Effect ◽  
Local Diversity ◽  
Global Environmental ◽  
Neutral Genetic Diversity ◽  
Delayed Maturation ◽  
Iteroparous Species

Genetic diversity at population scale, depends on species life-history traits, population dynamics and local and global environmental factors. We first investigate the effect of lifehistory traits on the neutral genetic diversity of a single population using a deterministic mathematical model. When the population is stable, we show that semelparous species with precocious maturation and iteroparous species with delayed maturation exhibit higher diversity because their life history traits tend to balance the lifetimes of non reproductive individuals (juveniles) and adults which reproduce. Then, we extend our model to a metapopulation to investigate the additional effect of dispersal on diversity. We show that dispersal may truly modify the local effect of life history on diversity. As a result, the diversity at the global scale of the metapopulation differ from the local diversity which is only described through local life history traits of the populations. In particular, dispersal usually promotes diversity at the global metapopulation scale.

scholarly journals Variation in life-history traits among Daphnia and its relationship to species-level responses to phosphorus limitation

2019 ◽  
Vol 6 (8) ◽  
pp. 191024 ◽  
Author(s):  
Rachel Hartnett
Keyword(s):  
Life History ◽  
Food Quality ◽  
Life History Traits ◽  
Growth Traits ◽  
Model Organism ◽  
Reproductive Traits ◽  
Phosphorus Limitation ◽  
Species Level ◽  
Trait Variation ◽  
P Limitation

Currently organisms are experiencing changes in their environment at an unprecedented rate. Therefore, the study of the contributions to and responses in traits linked to fitness is crucial, as they have direct consequences on a population's success in persisting under such a change. Daphnia is used as a model organism as the genus contains keystone primary consumers in aquatic food webs. A life-history table experiment (LHTE) using four species of Daphnia was conducted to compare variation in life-history traits among species across two different environmental conditions (high and low phosphorus availability). Results indicate that the food quality environment had the most impact on life-history traits, while genetic contributions to traits were higher at the species-level than clonal-level. Higher trait variation and species-level responses to P-limitation were more evident in reproductive traits, while growth traits were found to be less affected by food quality and had less variation. Exploring trait variation and potential plasticity in organisms is increasingly important to consider as a potential mechanism for population persistence given the fluctuations in environmental stressors we are currently experiencing.

scholarly journals Contrasting evolutionary responses in two co-distributed species of Galaxias (Pisces, Galaxiidae) in a river from the glaciated range in Southern Chile

2020 ◽  
Vol 7 (7) ◽  
pp. 200632 ◽  
Author(s):  
P. F. Victoriano ◽  
C. P. Muñoz-Ramírez ◽  
C. B. Canales-Aguirre ◽  
A. Jara ◽  
I. Vera-Escalona ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Population Size ◽  
Life History Traits ◽  
Genetic Differences ◽  
Southern Chile ◽  
Haplotype Networks ◽  
Galaxias Maculatus ◽  
Biological Differences ◽  
Over Time

Life-history traits are among the most important factors affecting population abundance and genetic diversity of species. Here, we analysed the genetic patterns of two Galaxias species with different life-history traits to investigate how these biological differences impacted their evolution in the Valdivia River basin, Southern Chile. We analysed mitochondrial DNA (mtDNA) sequences from 225 individuals of Galaxias maculatus and 136 of G. platei to compare patterns of genetic diversity, structure and demographic growth across the basin. Galaxias maculatus presented higher genetic diversity and higher genetic structure than G. platei . Demographic analyses showed G. maculatus kept a higher population size over time, with a signal of demographic expansion in the last 250 kyr. Whereas Galaxias platei , exhibited lower, but constant population size over time. Furthermore, haplotype networks revealed higher lineage diversity in G. maculatus with a tendency to occupy different areas of the basin. Coalescent simulations ruled out that genetic differences between species could be explained by stochastic processes (genetic drift), suggesting species-specific biological differences as responsible for the observed genetic differences. We discuss how differences in life-history traits and past glaciations interact to shape the evolutionary history of the two Galaxias species.

scholarly journals Predicting amphibian intraspecific diversity with machine learning: Challenges and prospects for integrating traits, geography, and genetic data

2020 ◽  
Author(s):  
Lisa N. Barrow ◽  
Emanuel Masiero da Fonseca ◽  
Coleen E. P. Thompson ◽  
Bryan C. Carstens
Keyword(s):  
Machine Learning ◽  
Genetic Diversity ◽  
Life History ◽  
Life History Traits ◽  
Phylogenetic Signal ◽  
Species Traits ◽  
Intraspecific Diversity ◽  
Northern Latitudes ◽  
Demographic Processes ◽  
Salamander Species

AbstractThe growing availability of genetic datasets, in combination with machine learning frameworks, offer great potential to answer long-standing questions in ecology and evolution. One such question has intrigued population geneticists, biogeographers, and conservation biologists: What determines intraspecific genetic diversity? This question is challenging to answer because many factors may influence genetic variation, including life history traits, historical influences, and geography, and the relative importance of these factors varies across taxonomic and geographic scales. Furthermore, interpreting the influence of numerous, potentially correlated variables is difficult with traditional statistical approaches. To address these challenges, we combined repurposed data with machine learning and investigated predictors of genetic diversity, focusing on Nearctic amphibians as a case study. We aggregated species traits, range characteristics, and >42,000 genetic sequences for 299 species using open-access scripts and various databases. After identifying important predictors of nucleotide diversity with random forest regression, we conducted follow-up analyses to examine the roles of phylogenetic history, geography, and demographic processes on intraspecific diversity. Although life history traits were not important predictors for this dataset, we found significant phylogenetic signal in genetic diversity within amphibians. We also found that salamander species at northern latitudes contain lower genetic diversity. Data repurposing and machine learning provide valuable tools for detecting patterns with relevance for conservation, but concerted efforts are needed to compile meaningful datasets with greater utility for understanding global biodiversity.

Genetic variation in sand pine (Pinusclausa)

1996 ◽  
Vol 26 (2) ◽  
pp. 244-254 ◽  
Author(s):  
Kathleen C. Parker ◽  
J.L. Hamrick
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Population Genetic ◽  
Genetic Distances ◽  
Species Level ◽  
Allozyme Diversity ◽  
Present Distribution ◽  
Genetic Bottlenecks ◽  
Florida Panhandle ◽  
Sand Pine

Pinusclausa (Chapm. ex Engelm.) Vasey ex Sarg. is a member of subsection Contortae that is restricted to Florida and the southern tip of Alabama. The present distribution of P. clausa is divided into two purported varieties: var. clausa in peninsular Florida and var. immuginata primarily in the Florida panhandle. We determined allozyme diversity and population genetic structure for 12 populations of var. clausa and 9 populations of var. immuginata. At the species level, 88% of the 26 loci examined were polymorphic. The genetic diversity maintained at both the species (Hes = 0.100) and population (Hep = 0.092) levels was low relative to most other pine species. Genetic differentiation among populations was also relatively low (GST = 0.054). Genetic distances between populations of the same variety (mean D = 0.006) were lower than genetic distances between populations of different varieties (mean D = 0.012). Although allele frequencies at individual loci differed significantly between the two varieties, each variety maintained nearly 99% of the genetic variation apparent at the species level (intervarietal differentiation, Gv = 0.014). The lower levels of genetic diversity in P. clausa may have resulted in part from genetic bottlenecks during periods of range retraction.

Sign in / Sign up

Export Citation Format

Share Document