scholarly journals Genética evolutiva del proceso de domesticación en plantas

2017 ◽  
pp. 131
Author(s):  
Beatriz Rendón ◽  
Juan Núñez-Farfán
Keyword(s):  
Population Genetics ◽  
Morphological Characteristics ◽  
Evolutionary Process ◽  
Phenotypic Change ◽  
Genetic Constitution ◽  
Methodological Framework ◽  
Plant Populations ◽  
Evolutionary Mechanisms ◽  
Incipient Domestication ◽  
Human Selection

Studies about the incipient domestication in plants often have based their analysis on morphological characteristics and have attributed those changes to the actions of artificial human selection. This paper remarks the importance of the analysis of incipient domestication in plants using the theoretical and methodological framework of both quantitative and population genetics. The premise of this work is that, considering domestication as an evolutionary process, much knowledge can be gained regarding the phenotypic change, its constraints, and the evolutionary mechanisms that have molded the genetic constitution of plant populations under domestication.

scholarly journals Retroposed New Genes Out of the X in Drosophila

2002 ◽  
Vol 12 (12) ◽  
pp. 1854-1859
Author(s):  
Esther Betrán ◽  
Kevin Thornton ◽  
Manyuan Long
Keyword(s):  
Population Genetics ◽  
Molecular Mechanisms ◽  
Sequence Data ◽  
Evolutionary Process ◽  
Significant Excess ◽  
Link Type ◽  
New Genes ◽  
Asymmetric Pattern ◽  
Unpublished Information

New genes that originated by various molecular mechanisms are an essential component in understanding the evolution of genetic systems. We investigated the pattern of origin of the genes created by retroposition in Drosophila. We surveyed the wholeDrosophila melanogaster genome for such new retrogenes and experimentally analyzed their functionality and evolutionary process. These retrogenes, functional as revealed by the analysis of expression, substitution, and population genetics, show a surprisingly asymmetric pattern in their origin. There is a significant excess of retrogenes that originate from the X chromosome and retropose to autosomes; new genes retroposed from autosomes are scarce. Further, we found that most of these X-derived autosomal retrogenes had evolved a testis expression pattern. These observations may be explained by natural selection favoring those new retrogenes that moved to autosomes and avoided the spermatogenesis X inactivation, and suggest the important role of genome position for the origin of new genes.[The sequence data from this study have been submitted to GenBank under accession nos. AY150701–AY150797. The following individuals kindly provided reagents, samples, or unpublished information as indicated in the paper: M.-L. Wu, F. Lemeunier, and P. Gibert.]

Abstracts of papers from the discussion meeting on mathematical genetics

1983 ◽  
Vol 390 (1798) ◽  
pp. 217-220
Keyword(s):  
Population Genetics ◽  
Restriction Endonuclease ◽  
Natural Populations ◽  
Genetic Data ◽  
Genetic Constitution ◽  
Genetic Process ◽  
Major Trend ◽  
Deductive Theory

A major trend of population genetics theory in the 1970s was the increased emphasis on inductive arguments, based on observed genetic data, rather than on deductive arguments based on theory and models. This occurred in part because the deductive theory had largely fulfilled its role of describing evolution as a genetic process, and in part because of the increasing amounts of data available on the genetic constitution of natural populations. Inference procedures raise difficulties not present in the deductive theory. Often conditional arguments are necessary since the data often must fulfil some condition to be observed. Different inference procedures, having different efficiencies, apply for data from different apparatuses. Care must be taken in deciding what it is that the inference concerns. These problems are illustrated by reference to restriction endonuclease techniques and ascertainment sampling.

scholarly journals Competing metabolic strategies in a multilevel selection model

2016 ◽  
Vol 3 (11) ◽  
pp. 160544 ◽  
Author(s):  
André Amado ◽  
Lenin Fernández ◽  
Weini Huang ◽  
Fernando F. Ferreira ◽  
Paulo R. A. Campos
Keyword(s):  
High Efficiency ◽  
Evolutionary Process ◽  
Structured Populations ◽  
High Rate ◽  
Energy Usage ◽  
Evolutionary Mechanisms ◽  
Mixed Populations ◽  
Selection For ◽  
Metabolic Strategies ◽  
Low Rate

The evolutionary mechanisms of energy efficiency have been addressed. One important question is to understand how the optimized usage of energy can be selected in an evolutionary process, especially when the immediate advantage of gathering efficient individuals in an energetic context is not clear. We propose a model of two competing metabolic strategies differing in their resource usage, an efficient strain which converts resource into energy at high efficiency but displays a low rate of resource consumption, and an inefficient strain which consumes resource at a high rate but at low yield. We explore the dynamics in both well-mixed and structured populations. The selection for optimized energy usage is measured by the likelihood that an efficient strain can invade a population of inefficient strains. It is found that the parameter space at which the efficient strain can thrive in structured populations is always broader than observed in well-mixed populations.

scholarly journals Comparative Mitogenomic Analysis Reveals Dynamics of Intron Within and Between Tricholoma Species and Phylogeny of Basidiomycota

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenli Huang ◽  
Huiyu Feng ◽  
Wenying Tu ◽  
Chuan Xiong ◽  
Xin Jin ◽  
...  
Keyword(s):  
Large Scale ◽  
Mitochondrial Gene ◽  
Morphological Characteristics ◽  
Evolutionary Process ◽  
Evolutionary Analysis ◽  
Species Classification ◽  
Next Generation Sequencing Technology ◽  
Intergenic Sequences ◽  
Maximum Likelihood Methods ◽  
Tree Topologies

The genus of Tricholoma is a group of important ectomycorrhizal fungi. The overlapping of morphological characteristics often leads to the confusion of Tricholoma species classification. In this study, the mitogenomes of five Tricholoma species were sequenced based on the next-generation sequencing technology, including T. matsutake SCYJ1, T. bakamatsutake, T. terreum, T. flavovirens, and T. saponaceum. These five mitogenomes were all composed of circular DNA molecules, with sizes ranging from 49,480 to 103,090 bp. Intergenic sequences were considered to be the main factor contributing to size variations of Tricholoma mitogenomes. Comparative mitogenomic analysis showed that the introns of the Agaricales mitogenome experienced frequent loss/gain events. In addition, potential gene transfer was detected between the mitochondrial and nuclear genomes of the five species of Tricholoma. Evolutionary analysis showed that the rps3 gene of the Tricholoma species was under positive selection or relaxed selection in the evolutionary process. In addition, large-scale gene rearrangements were detected between some Tricholoma species. Phylogenetic analysis using the Bayesian inference and maximum likelihood methods based on a combined mitochondrial gene set yielded identical and well-supported tree topologies. This study promoted the understanding of the genetics, evolution, and phylogeny of the Tricholoma genus and related species.

scholarly journals Manejo de la vegetación, domesticación de plantas y origen de la agricultura en Mesoamérica

2017 ◽  
pp. 31 ◽  
Author(s):  
Alejandro Casas ◽  
Javier Caballero ◽  
Cristina Mapes ◽  
Sergio Zárate
Keyword(s):  
Plant Communities ◽  
Artificial Selection ◽  
Plant Management ◽  
Useful Plants ◽  
Plant Populations ◽  
Stenocereus Stellatus ◽  
Morphological Differences ◽  
Anoda Cristata ◽  
Incipient Domestication

A model of domestication of  plants in Mesoamerica based  on  selective management  of  plant populations and  communities by silvicultural practices is analyzed. Archaeological and  ethnobotanical information  suggests that  intentional manipulation of vegetation by Mesoamerican peoples has occurred in  past  and present times  in  order to  control availability  of  useful  plants. Forms of  management of  plant communities or  populations have  included tolerance, protection and  enhancement of individual  plants of  particular species  during clearance of  vegetation and  other ways of  perturbation. Processes of  artificial selection  (selection  in situ) may be carried out  through these  forms  of plant  management. These processes may cause significant morphological differences between wild and  managed populations as illustrated by the  cases  discussed here of  Anoda  cristata,  Crotalaria pumila,  Leucaena esculenta and  Stenocereus stellatus. Processes of artificial selection in  situ are mechanisms of  incipient domestication of  plants which  appear to  have  been   carried out  in Mesoamerica, perhaps since pre-agricultural times,  and  that  could contribute  to explain the processes that  led to  the  origins of agriculture in this region.

scholarly journals Comparative analysis of morphological characteristics of beech leaves from the European provenance trial

2019 ◽  
pp. 145-174
Author(s):  
Marina Nonic ◽  
Dijana Cortan ◽  
Tatjana Batalo ◽  
Mirjana Sijacic-Nikolic
Keyword(s):  
Comparative Analysis ◽  
Genetic Variability ◽  
Morphological Characteristics ◽  
Climatic Conditions ◽  
Genetic Constitution ◽  
Provenance Trial ◽  
Morphological Markers ◽  
Mean Values ◽  
Leaf Characteristics ◽  
The Mean

The paper presents the results of the research conducted within the European provenance beech trial, in the Teaching Base of the Faculty of Forestry - Debeli Lug. To assess the inter- -provenance genetic variability of beech, using morphological markers, and comparative analysis of the results obtained in two successive years, 10 trees per each selected provenance were sampled. Thirty leaves were collected from each tree (total of 300 leaves per provenance per year). The inter-provenance differences of all morphological leaf characteristics were statistically significant and can be assumed to be the result of the genetic constitution of the provenances themselves. Based on the comparative analysis of the morphological characteristics of beech leaves from 13 different provenances in two research years, it was found that the mean values of most analyzed morphological characteristics were higher in 2017, compared to the results from 2016. Such results could be explained by the different climatic conditions that prevailed in the provenance trial in research years.

scholarly journals Mechanism of evolution by genetic assimilation

2018 ◽  
Author(s):  
Ken Nishikawa ◽  
Akira R. Kinjo
Keyword(s):  
Environmental Stress ◽  
Evolutionary Process ◽  
Fruit Flies ◽  
Genetic Assimilation ◽  
Phenotypic Change ◽  
Genetic Mutations ◽  
Initial State ◽  
Central Process ◽  
Cooperative Model ◽  
Phenotypic Changes

AbstractConrad H. Waddington discovered the phenomenon of genetic assimilation through a series of experiments on fruit flies. In those experiments, artificially exerted environmental stress induced plastic phe-notypic changes in the fruit flies, but after some generations the same phenotypic variant started to appear without the environmental stress. Both the initial state (where the phenotypic changes were environmentally induced and plastic) and the final state (where the phenotypic changes were genetically fixed and constitutive) are experimental facts. However, it remains unclear how the environmentally induced phenotypic change in the first generation becomes genetically fixed in the central process of genetic assimilation itself. We have argued that the key to understanding the mechanism of genetic assimilation lies in epigenetics, and proposed the “cooperative model” in which the evolutionary process depends on both genetic and epigenetic factors. Evolutionary simulations based on the cooperative model reproduced the process of genetic assimilation. Detailed analysis of the trajectories has revealed genetic assimilation is a process in which epigenetically induced phe-notypic changes are incrementally and statistically replaced with multiple minor genetic mutations through natural selection. In this scenario, epigenetic and genetic changes may be considered as mutually independent but equivalent in terms of their effects on phenotypic changes. This finding rejects the common (and confused) hypothesis that epigenetically induced phe-notypic changes depend on genetic mutations. Furthermore, we argue that transgenerational epigenetic inheritance is not required for evolution by genetic assimilation.

scholarly journals Landscape and taxon age are associated with differing patterns of hybridization in two Eucalyptus (Myrtaceae) subgenera

2020 ◽  
Vol 127 (1) ◽  
pp. 49-62
Author(s):  
T P Robins ◽  
R M Binks ◽  
M Byrne ◽  
S D Hopper
Keyword(s):  
Evolutionary Process ◽  
F1 Hybrids ◽  
Divergence Times ◽  
Eucalyptus Species ◽  
Reproductive Barriers ◽  
Nucleotide Polymorphism ◽  
Plant Populations ◽  
Single Nucleotide ◽  
Clonal Spread

Abstract Background and Aims Hybridization is an important evolutionary process that can have a significant impact on natural plant populations. Eucalyptus species are well known for weak reproductive barriers and extensive hybridization within subgenera, but there is little knowledge of whether patterns of hybridization differ among subgenera. Here, we examine eucalypts of Western Australia’s Stirling Range to investigate how patterns of hybridization are associated with landscape and taxon age between the two largest Eucalyptus subgenera: Eucalyptus and Symphyomyrtus. In doing so, we tested a hypothesis of OCBIL (old, climatically buffered, infertile landscape) theory that predicts reduced hybridization on older landscapes. Methods Single nucleotide polymorphism markers were applied to confirm the hybrid status, parentage and genetic structure of five suspected hybrid combinations for subg. Eucalyptus and three combinations for subg. Symphyomyrtus. Key Results Evidence of hybridization was found in all combinations, and parental taxa were identified for most combinations. The older parental taxa assessed within subg. Eucalyptus, which are widespread on old landscapes, were identified as well-defined genetic entities and all hybrids were exclusively F1 hybrids. In addition, many combinations showed evidence of clonality, suggesting that the large number of hybrids recorded from some combinations is the result of long-term clonal spread following a few hybridization events rather than frequent hybridization. In contrast, the species in subg. Symphyomyrtus, which typically occur on younger landscapes and are more recently evolved, showed less distinction among parental taxa, and where hybridization was detected, there were high levels of introgression. Conclusions Reduced hybridization in subg. Eucalyptus relative to extensive hybridization in subg. Symphyomyrtus affirmed the hypothesis of reduced hybridization on OCBILs and demonstrate that clade divergence times, landscape age and clonality are important drivers of differing patterns of speciation and hybridization in Eucalyptus.

scholarly journals A Duality Approach to the Genealogies of Discrete Nonneutral Wright-Fisher Models

2009 ◽  
Vol 2009 ◽  
pp. 1-22 ◽  
Author(s):  
Thierry E. Huillet
Keyword(s):  
Population Genetics ◽  
Population Dynamics ◽  
Large Class ◽  
Elementary Algebra ◽  
Evolutionary Mechanisms ◽  
Potential Interest ◽  
Completely Monotone ◽  
Duality Approach ◽  
Neutral Case

Discrete ancestral problems arising in population genetics are investigated. In the neutral case, the duality concept has been proved of particular interest in the understanding of backward in time ancestral process from the forward in time branching population dynamics. We show that duality formulae still are of great use when considering discrete nonneutral Wright-Fisher models. This concerns a large class of nonneutral models with completely monotone (CM) bias probabilities. We show that most classical bias probabilities used in the genetics literature fall within this CM class or are amenable to it through some “reciprocal mechanism” which we define. Next, using elementary algebra on CM functions, some suggested novel evolutionary mechanisms of potential interest are introduced and discussed.

scholarly journals Spatial Population Genetics: It's About Time

2019 ◽  
Vol 50 (1) ◽  
pp. 427-449 ◽  
Author(s):  
Gideon S. Bradburd ◽  
Peter L. Ralph
Keyword(s):  
Population Genetics ◽  
Genetic Variation ◽  
Evolutionary Process ◽  
Genetic Data ◽  
Space And Time ◽  
Spatial Population ◽  
Alive Today

Many important questions about the history and dynamics of organisms have a geographical component: How many are there, and where do they live? How do they move and interbreed across the landscape? How were they moving a thousand years ago, and where were the ancestors of a particular individual alive today? Answers to these questions can have profound consequences for our understanding of history, ecology, and the evolutionary process. In this review, we discuss how geographic aspects of the distribution, movement, and reproduction of organisms are reflected in their pedigree across space and time. Because the structure of the pedigree is what determines patterns of relatedness in modern genetic variation, our aim is to thus provide intuition for how these processes leave an imprint in genetic data. We also highlight some current methods and gaps in the statistical toolbox of spatial population genetics.

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