Sabiia Seb
PortuguêsEspañolEnglish
Embrapa
        Busca avançada

Botão Atualizar


Botão Atualizar

Ordenar por: RelevânciaAutorTítuloAnoImprime registros no formato resumido
Registros recuperados: 3
Primeira ... 1 ... Última
Imagem não selecionada

Imprime registro no formato completo
A critical view to explanations for the maximal value of 50 % of genetic recombination RChHN
VALENZUELA,CARLOS Y; PÉREZ-ALZOLA,PATRICIA; SANTOS,MANUEL J.
The maximal value of 50 % of genetic recombination (RF = recombination fraction) between two linked gene loci has been explained by two models: (i) the restriction of crossovers to only two of the four chromatids of a tetrad (tetrad model); (ii) the limit of the occurrence of an odd number of crossovers between two loci, when the expected number of crossovers tends to infinite (odd-even model). This article shows that (i) is wrong. If tetrads were responsible for the maximal 50 % RF, sister chromatid exchanges (SCE) should display a maximal 100 % RF. In mammalian CHO cells we found that SCE yield a maximal 50 % recombination. Also, we demonstrated that the maximal 50 % RF for tetrads occurs because the sum of odd order coefficients in the binomial...
Tipo: Journal article Palavras-chave: 50 % recombination; Tetrads; Odd-even crossovers; SCE.
Ano: 2001 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2001000000015
Imagem não selecionada

Imprime registro no formato completo
Neutral illusions, selective nightmares and autopoietic madness RChHN
VALENZUELA,CARLOS Y.
Until now, there are three evolutionary models: I) The Synthetic Theory of Evolution (STE) also named as the Neo-Darwinian model; II) The Neutral Theory of Evolution (NTE) with its daughter the Nearly-Neutral Theory of Evolution (NNTE); III) The Theory of Evolution by means of Natural Drift (NDTE) (Valenzuela 2007, 2009). All these theories accept that variation of genomes of living beings emerges by mutation. They disagree in relation of the causes of the acquisition and maintenance of the living being organization. STE proposes that the main factor for the acquisition and maintenance of fixated organization is selection and a marginal role of genetic drift. NTE proposed that the acquisition and maintenance of fixated organization is drift with a marginal...
Tipo: Journal article Palavras-chave: Synthetic Theory of Evolution; Neutral Theory of Evolution; Natural Drift.
Ano: 2010 URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-078X2010000400004
Imagem não selecionada

Imprime registro no formato completo
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
Registros recuperados: 3
Primeira ... 1 ... Última
 

Empresa Brasileira de Pesquisa Agropecuária - Embrapa
Todos os direitos reservados, conforme Lei n° 9.610
Política de Privacidade
Área restrita

Embrapa
Parque Estação Biológica - PqEB s/n°
Brasília, DF - Brasil - CEP 70770-901
Fone: (61) 3448-4433 - Fax: (61) 3448-4890 / 3448-4891 SAC: https://www.embrapa.br/fale-conosco

Valid HTML 4.01 Transitional