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Autocorrelação espacial das freqüências alélicas em subpopulações de cagaiteira (Eugenia dysenterica DC., Myrtaceae) no sudeste de Goiás Rev. Bras. Bot.
TELLES,MARIANA P. DE C.; DINIZ-FILHO,JOSÉ ALEXANDRE F.; COELHO,ALEXANDRE S.G.; CHAVES,LÁZARO J..
Dentre as diversas árvores frutíferas nativas dos cerrados, a cagaiteira (Eugenia dysenterica DC.) merece destaque pelo seu amplo potencial econômico. A fim de fornecer algumas informações relativas ao padrão espacial da variabilidade genética desta espécie, foram realizadas análises de autocorrelação espacial das freqüências alélicas em dez subpopulações locais da região sudeste do Estado de Goiás. Foram utilizados marcadores isoenzimáticos, em um total de seis sistemas enzimáticos (SKDH, 6-PGD, alfa-EST, MDH, PGI e PGM), com oito locos polimórficos. Foi realizada uma análise de autocorrelação espacial, utilizando índices I de Moran estimados em quatro classes de distância geográfica. Os correlogramas mostraram que, de fato, a divergência genética está...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Eugenia dysenterica; Isozymes; Neutral evolution; Spatial autocorrelation.
Ano: 2001 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-84042001000200003
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Within selection RChHN
VALENZUELA,CARLOS Y.
The synthetic theory of evolution proposes that biotic variations generated by mutation are mostly fixed, lost or maintained polymorphic by natural selection, with a marginal effect due to genetic drift. Based on the theory of autopoiesis some authors have proposed that selection is unable to explain most evolutionary changes, and natural or phenotype drift and epigenesis are the mechanisms that explain most of evolution. This view misunderstands basic evolutionary notions. Selection is a natural process that occurs with or without evolution; it does not explain evolution, it is a factor of the evolutionary process. The concept of autopoiesis implies an invariant condition of living beings, thus, it cannot explain and even less produce evolution conceived...
Tipo: Journal article Palavras-chave: Autopoiesis; Evolution; Natural drift; Neutral evolution; Selection; Synthetic theory.
Ano: 2007 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2007000100009
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Mutations in the melanocortin-1 receptor (MC1R) gene have no influence on the distinct patterns of melanic plumage found in the manakins of the genus Antilophia (Aves: Pipridae) Anais da ABC (AABC)
LUNA,LEILTON W.; SILVA,WEBER A. GIRÃO E; ARARIPE,JULIANA; PEREIRA,ISADORA T.F.; D'HORTA,FERNANDO M.; SAMPAIO,IRACILDA; SCHNEIDER,HORACIO; RÊGO,PÉRICLES S. DO.
Abstract The melanocortin-1 receptor gene is the most widely-used marker for the investigation of the genetic determination of melanic plumage patterns. Studies of a number of wild bird species have shown an association between non-synonymous mutations of the MC1R gene and the presence of melanic variants. The genus Antilophia (Pipridae) includes only two manakin species (A. galeata and A. bokermanni), which are distinguished primarily by the differences in the pattern of melanic coloration of the plumage of the mantle in the adult males. In A. galeata, this plumage is black, while in A. bokermanni, it is predominantly white. This study investigates the possible association between mutations of the MC1R marker and the variation in plumage coloration...
Tipo: Info:eu-repo/semantics/article Palavras-chave: Candidate gene; Manakin; Melanism; Neutral evolution; Plumage color.
Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652018000602873
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Misconceptions and false expectations in neutral evolution Biol. Res.
VALENZUELA,CARLOS Y..
Neutral evolution results from random recurrent mutation and genetic drift. A small part of random evolution, that which is related to protein or DNA polymorphisms, is the subject of the Neutral Theory of Evolution. One of the foundations of this theory is the demonstration that the mutation rate (m) is equal to the substitution rate. Since both rates are independent of population size, they are independent of drift, which is dependent upon population size. Neutralists have erroneously equated the substitution rate with the fixation rate, despite the fact that they are antithetical conceptions. The neutralists then applied the random walk stochastic model to justify alleles or bases that were fixated or eliminated. In this model, once the allele or base...
Tipo: Journal article Palavras-chave: Neutral evolution; Neutral theory; Misconceptions; Bases fixation; Elimination.
Ano: 2000 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602000000300004
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Foundational errors in the Neutral and Nearly-Neutral theories of evolution in relation to the Synthetic Theory: Is a new evolutionary paradigm necessary? Biol. Res.
Valenzuela,Carlos Y.
The Neutral Theory of Evolution (NTE) proposes mutation and random genetic drift as the most important evolutionary factors. The most conspicuous feature of evolution is the genomic stability during paleontological eras and lack of variation among taxa; 98% or more of nucleotide sites are monomorphic within a species. NTE explains this homology by random fixation of neutral bases and negative selection (purifying selection) that does not contribute either to evolution or polymorphisms. Purifying selection is insufficient to account for this evolutionary feature and the Nearly-Neutral Theory of Evolution (N-NTE) included negative selection with coefficients as low as mutation rate. These NTE and N-NTE propositions are thermodynamically (tendency to random...
Tipo: Journal article Palavras-chave: Fixation; Loss; Neutral evolution; Polymorphism; Randomness; Selectiveness.
Ano: 2013 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602013000200001
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Internucleotide correlations and nucleotide periodicity in Drosophila mtDNA: New evidence for panselective evolution Biol. Res.
Valenzuela,Carlos Y.
Analysis for the homogeneity of the distribution of the second base of dinucleotides in relation to the first, whose bases are separated by 0, 1, 2,... 21 nucleotide sites, was performed with the VIH-1 genome (cDNA), the Drosophila mtDNA, the Drosophila Torso gene and the human p-globin gene. These four DNA segments showed highly significant heterogeneities of base distributions that cannot be accounted for by neutral or nearly neutral evolution or by the "neighbor influence" of nucleotides on mutation rates. High correlations are found in the bases of dinucleotides separated by 0, 1 and more number of sites. A periodicity of three consecutive significance values (measured by the x²9) was found only in Drosophila mtDNA. This periodicity may be due to an...
Tipo: Journal article Palavras-chave: Nucleotide heterogeneity; DNA periodicity; Dinucleotide analysis; Neutral evolution; Panselective evolution.
Ano: 2010 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000400014
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Fixations of the HIV-1 env gene refute neutralism: New evidence for pan-selective evolution Biol. Res.
Valenzuela,Carlos Y; Flores,Sergio V; Cisternas,Javier.
We examined 103 nucleotide sequences of the HIV-1 env gene, sampled from 35 countries and tested: I) the random (neutral) distribution of the number of nucleotide changes; II) the proportion of bases at molecular equilibrium; III) the neutral expected homogeneity of the distribution of new fxated bases; IV) the hypothesis of the neighbor infuence on the mutation rates in a site. The expected random number of fxations per site was estimated by Bose-Einstein statistics, and the expected frequencies of bases by matrices of mutation-fxation rates. The homogeneity of new fxations was analyzed using χ2 and trinomial tests for homogeneity. Fixations of the central base in trinucleotides were used to test the neighbor infuence on base substitutions....
Tipo: Journal article Palavras-chave: Bose-Einstein distribution; Fxations; HIV-1 env gene; Neutral evolution; Pan-selective evolution.
Ano: 2010 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97602010000200002
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