James Shapiro: o DNA móvel e a evolução no século 21

terça-feira, janeiro 26, 2010

Mobile DNA and evolution in the 21st century

James A Shapiro

Mobile DNA 2010, 1:4doi:10.1186/1759-8753-1-4

Published: 25 January 2010

Abstract (provisional)

Scientific history has had a profound effect on the theories of evolution. At the beginning of the 21st century, molecular cell biology has revealed a dense structure of information-processing networks that use the genome as an interactive read-write (RW) memory system rather than an organism blueprint. Genome sequencing has documented the importance of mobile DNA activities and major genome restructuring events at key junctures in evolution: exon shuffling, changes in cis-regulatory sites, horizontal transfer, cell fusions and whole genome doublings (WGDs). The natural genetic engineering functions that mediate genome restructuring are activated by multiple stimuli, in particular by events similar to those found in the DNA record: microbial infection and interspecific hybridization leading to the formation of allotetraploids. These molecular genetic discoveries, plus a consideration of how mobile DNA rearrangements increase the efficiency of generating functional genomic novelties, make it possible to formulate a 21st century view of interactive evolutionary processes. This view integrates contemporary knowledge of the molecular basis of genetic change, major genome events in evolution, and stimuli that activate DNA restructuring with classical cytogenetic understanding about the role of hybridization in species diversification.

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NOTA DESTE BLOGGER:

James A. Shapiro é um dos maiores nomes em genética no mundo. Eu notei o emprego da conjunção 'although' (embora) várias vezes no artigo. Na página 26, eu destaco o seguinte parágrafo:

Although there remain many gaps in our knowledge, we are now in a position to outline a distinctively 21st century scenario for evolutionary change. The scenario includes the following elements:

(1) hereditary variation arises from the non-random action of built-in biochemical systems that mobilize DNA and carry out natural genetic engineering;

Fui, nem sei por que, pensando que dia mais, dia menos a teoria do Design Inteligente vai ter que ser considerada pela Academia de modo mais diferente do que tem sido tratada até aqui: natural genetic engineering???

Sem me esquecer qie nas páginas 27 e 28, Shapiro dá uma estocada nos teóricos e proponentes da TDI:


This 21st century view of evolution establishes a reasonable connection between ecological changes, cell and
organism responses, widespread genome restructuring, and the rapid emergence of adaptive inventions. It also answers the objections to conventional theory raised by intelligent design advocates, because evolution by natural genetic engineering has the capacity to generate complex novelties. In other words, our best defense against antiscience obscurantism comes from the study of mobile DNA because that is the subject
that has most significantly transformed evolution from natural history into a vibrant empirical science.

Eu faço aqui uma aposta em cima da tese de Shapiro: quanto mais a evolução (seja lá o que isso signifique em ciência), for um processo considerado como sendo uma resposta controlada, a proposição de Shapiro está mais para Design Inteligente do que simplesmente engenharia genética naturalista. Quem viver, verá!


Leia cum grano salis o artigo de Shapiro, arrependa-se e converta-se epistemicamente ao DI... Não doi, é somente uma mudança paradigmática em biologia evolutiva. Nada mais, nada menos. E os cientistas que praticam a tal de 'ciência normal'? A 'solução biológica' vai dar conta deles brevemente, e uma nova geração de cientistas que não está comprometida com o paradigma consensual da Akademia, é mais inclinada a aceitar as novas ideias científicas... (Thomas Kuhn, A estrutura das revoluções científicas).