Energy Revolution Key to Complex Life: Depends on Mitochondria, Cells' Tiny Power Stations
ScienceDaily (Oct. 21, 2010) — The evolution of complex life is strictly dependent on mitochondria, the tiny power stations found in all complex cells, according to a new study by Dr Nick Lane, from UCL (University College London), and Dr William Martin, from the University of Dusseldorf.
Artist's rendering of basic cell structure, including mitochondria. (Credit: iStockphoto/Sebastian Kaulitzki)
"The underlying principles are universal. Energy is vital, even in the realm of evolutionary inventions," said Dr Lane, UCL Department of Genetics, Evolution and Environment. "Even aliens will need mitochondria."
For 70 years scientists have reasoned that evolution of nucleus was the key to complex life. Now, in work published in Nature, Lane and Martin reveal that in fact mitochondria were fundamental to the development of complex innovations like the nucleus because of their function as power stations in the cell.
"This overturns the traditional view that the jump to complex 'eukaryotic' cells simply required the right kinds of mutations. It actually required a kind of industrial revolution in terms of energy production," explained Dr Lane.
At the level of our cells, humans have far more in common with mushrooms, magnolias and marigolds than we do with bacteria. The reason is that complex cells like those of plants, animals and fungi have specialized compartments including an information centre, the nucleus, and power stations -- mitochondria. These compartmentalised cells are called 'eukaryotic', and they all share a common ancestor that arose just once in four billion years of evolution.
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"If evolution works like a tinkerer, evolution with mitochondria works like a corps of engineers," said Dr Martin.
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Read more here/Leia mais aqui: Science Daily
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Nature 467, 929-934 (21 October 2010) | doi:10.1038/nature09486; Published online 20 October 2010
The energetics of genome complexity
Nick Lane1 & William Martin2
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Within the cells of humans and all other modern creatures are lots of tiny mitochondria (shown here in pink), which may have been the key to the evolution of complex multicellular life billions of years ago. Credit: Donald Bliss and Sriram Subramaniam, National Library of Medicine, NIH
Source/Fonte: Physorg
Abstract
All complex life is composed of eukaryotic (nucleated) cells. The eukaryotic cell arose from prokaryotes just once in four billion years, and otherwise prokaryotes show no tendency to evolve greater complexity. Why not? Prokaryotic genome size is constrained by bioenergetics. The endosymbiosis that gave rise to mitochondria restructured the distribution of DNA in relation to bioenergetic membranes, permitting a remarkable 200,000-fold expansion in the number of genes expressed. This vast leap in genomic capacity was strictly dependent on mitochondrial power, and prerequisite to eukaryote complexity: the key innovation en route to multicellular life.
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ALÔ MEC/SEMTEC/PNLEM:
Se a hipótese de Lane e Martin estiver correta, isso significa que nossos livros terão, pelo menos, que mencionar esta nova hipótese como possível candidata a melhor explicar a origem da complexidade nas formas bióticas.
Eu gostei mesmo foi da declaração do Dr. Martin:
"If evolution works like a tinkerer, evolution with mitochondria works like a corps of engineers".
O Massimo Pigliucci, aquele que sugeriu um INDEX PROHIBITORUM de palavras que reflitam ideias de engenharia (teleologia) para evitar a interpretação científica errônea dos fatos científicos que ocorrem nas coisas bióticas, deve estar bufando de raiva com esta declaração de a evolução ser através de design inteligente...
