Celebrando 10 anos do livro Icons of Evolution de Jonathan Wells que detonou o fato, Fato, FATO da evolução nos livros didáticos

terça-feira, novembro 30, 2010



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NOTA DESTE BLOGGER:

Nós tentamos a tradução e publicação deste livro expondo com evidências que a abordagem da evolução nos livros didáticos de biologia do ensino médio aprovados pelo MEC/SEMTEC/PNLEM utilizou de duas fraudes e diversas evidências científicas distorcidas para corroborar o fato, Fato, FATO da evolução, mas não conseguimos editoras que aceitassem este desafio. Pasmem, nem as chamadas editoras cristãs...

À medidas que os vídeos forem postados no Discovery Institute, eles serão postados aqui neste blog.

Esta é uma homenagem a Jonathan Wells, biólogo molecular, que me introduziu ao grupo do Design Inteligente.

Jon, parece que a palmada na traseira (foi a Eugenie Scott quem disse do livro) está doendo até agora na Nomenklatura científica.  

Koalas: talvez o mais seletivo dos marsupiais

Koala Bears May Be the 'Pickiest' Marsupials Around

ScienceDaily (Nov. 29, 2010) — Koalas may be the pickiest marsupials around: They evolved to feed almost exclusively on the leaves of Eucalyptus trees, and they are highly selective when it comes to which species and even which individual trees they visit. When the furry leaf-eater settles on a particular tree, it relies on a number of factors, including taste, to make its selection. In a study published in the November issue of Ecology, a journal of the Ecological Society of America (ESA), researchers used koala feeding preferences to design a new method that could help ecologists and conservationists map habitats.

A mother koala with its baby joey. (Credit: iStockphoto/Craig Dingle)

Ben Moore and colleagues from the Australian National University and the Macaulay Land Use Research Institute in Scotland collected and analyzed leaves from all the trees available to koalas in a Eucalyptus woodland using a near-infrared spectroscopic model. To define "palatability" in koala terms, the researchers tested leaves on captive koalas and recorded how much they ate: They found that the koalas ate less foliage when it contained lots of lipid-soluble phenolic chemicals known as formylated phloroglucinol compounds (FPCs). The researchers then tracked koala tree visits in a Eucalyptus woodland to show that tree preferences of wild koalas could be predicted using the taste preferences of the captive koalas. The researchers also determined the chemical composition of the trees' leaves and other factors such as tree size and neighborhood quality, or how attractive each tree's neighbors were to koalas.
...

Read more here/Leia mais aqui: Science Daily

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Moore, Ben D., Ivan R. Lawler, Ian R. Wallis, Colin M. Beale, and William J. Foley. 2010. Palatability mapping: a koala's eye view of spatial variation in habitat quality. Ecology 91:3165–3176. [doi:10.1890/09-1714.1]

Articles

Palatability mapping: a koala's eye view of spatial variation in habitat quality

Ben D. Moore1,4, Ivan R. Lawler2,5, Ian R. Wallis1, Colin M. Beale3,6, and William J. Foley1

1Evolution, Ecology and Genetics, Research School of Biology, Australian National University, Canberra, ACT 0200 Australia

2School of Earth and Environmental Sciences, James Cook University of North Queensland, Douglas, Queensland 4811 Australia

3Ecology Group, Macaulay Land Use Research Institute, Aberdeen AB158QH United Kingdom

Ecologists trying to understand the value of habitat to animals must first describe the value of resources contained in the habitat to animals and, second, they must describe spatial variation in resource quality at a resolution relevant to individual animal foraging. We addressed these issues in a study of koalas (Phascolarctos cinereus) in a Eucalyptus woodland. We measured beneficial and deterrent chemical characteristics as well as the palatability of trees using a near-infrared spectroscopic model based on direct feeding experiments. Tree use by koalas was influenced by tree size and foliar quality but was also context-dependent: trees were more likely to be visited if they were surrounded by small, unpalatable trees or by large, palatable trees. Spatial autocorrelation analysis and several mapping approaches demonstrated that foliar quality is spatially structured in the woodland at a scale relevant to foraging decisions by koalas and that the spatial structure is an important component of habitat quality.

Keywords: associational defense, Australian Eucalyptus woodland, formylated phloroglucinol compounds, generalized additive mixed modeling, habitat quality, koala, NIRS, patch use, Phascolarctos cinereus, plant secondary metabolites,spatial autocorrelation

Received: September 18, 2009; Revised: February 11, 2010; Accepted: March 3, 2010; Revised: March 25, 2010

4Present address: Ecology Group, Macaulay Land Use Research Institute, Craigiebuckler, Aberdeen AB158QH United Kingdom. E-mail: b.moore@macaulay.ac.uk

5Present address: Department of the Environment, Water, Heritage and the Arts, GPO Box 787, Canberra, ACT 2601 Australia.

6Present address: Department of Biology (Area 18), P.O. Box 373, University of York, YO105YW United Kingdom.

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Evolução dos grandes mamíferos

30/11/2010

Agência FAPESP – Nos primeiros 140 milhões de anos de sua história evolutiva, os mamíferos eram pequenos, não ultrapassando os 15 quilos, e ocupavam poucos nichos ecológicos. Tudo mudou após a extinção dos dinossauros, há cerca de 65 milhões de anos, quando os mamíferos explodiram tanto em diversidade como em tamanho.

Um novo estudo, publicado na revista Science, ajuda a tentar entender esse notável salto evolutivo. Felisa Smith, da Universidade do Novo México, e colegas reuniram dados de fósseis que indicam os tamanhos de mamíferos terrestres pertencentes a cada ordem taxonômica, em cada continente e durante a sua história evolutiva.

Estudo na Science explica por que os mamíferos, que até então não passavam dos 15 quilos, cresceram e se diversificaram tanto após a extinção dos dinossauros (divulgação)

A análise dos dados colhidos indica que o tamanho geral dos mamíferos aumentou rapidamente e depois se estabilizou, após cerca de 25 milhões de anos. Segundo os autores da pesquisa, esse padrão foi comum para a maioria dos continentes, embora não tenha sido conclusivo para a América do Sul.

Os pesquisadores também experimentaram diferentes hipóteses para a evolução até o tamanho corporal máximo. Segundo eles, aparentemente essa tendência não foi um resultado aleatório ou inevitável do aumento na complexidade das espécies.

Os mamíferos também não atingiram eventuais limites biomecânicos, aponta o estudo. Em vez disso, o principal motor do crescimento teria sido a diversificação para o preenchimento de nichos ecológicos deixados vagos pelos dinossauros.

Ou seja, sem os grandes répteis, entraram em cena os mamíferos gigantes, ocupando seu espaço. Para os autores da pesquisa, os limites dos corpos devem ter sido ditados pelas condições climáticas e pela área disponível para sua ocupação.

“Durante o Mezosoico, os mamíferos eram pequenos. Mas, uma vez extintos os dinossauros, os mamíferos evoluíram para se tornar muito maiores, à medida que se diversificaram e preencheram nichos ecológicos disponíveis. Esse fenômeno é bem documentado na América do Norte e verificamos que o mesmo ocorre em todo o mundo”, disse John Gittleman, da Universidade de Georgia, nos Estados Unidos, um dos autores do estudo.

O artigo The Evolution of Maximum Body Size of Terrestrial Mammals (10.1126/science.1194830), de Felisa Smith e outros, pode ser lido por assinantes da Science em www.sciencemag.org/content/330/6008/1216.

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Science 26 November 2010: 
Vol. 330 no. 6008 pp. 1216-1219 
DOI: 10.1126/science.1194830
REPORT

The Evolution of Maximum Body Size of Terrestrial Mammals

Felisa A. Smith1,*, Alison G. Boyer2, James H. Brown1, Daniel P. Costa3, Tamar Dayan4, S. K. Morgan Ernest5, Alistair R. Evans6, Mikael Fortelius7, John L. Gittleman8, Marcus J. Hamilton1, Larisa E. Harding9, Kari Lintulaakso7, S. Kathleen Lyons10, Christy McCain11, Jordan G. Okie1, Juha J. Saarinen7, Richard M. Sibly12, Patrick R. Stephens8, Jessica Theodor13 and Mark D. Uhen13

+Author Affiliations

1Department of Biology, MSC03 2020, University of New Mexico, Albuquerque, NM 87131, USA.
2Department of Ecology and Evolutionary Biology, Yale University, Box 208106, New Haven, CT 06520, USA.
3Department of Ecology and Evolutionary Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
4Department of Zoology, Tel-Aviv University, Tel Aviv 69978, Israel.
5Department of Biology and Ecology Center, Utah State University, Logan, UT 84322, USA.
6School of Biological Sciences, Monash University, VIC 3800, Australia.
7Department of Geosciences and Geography, Institute of Biotechnology, Post Office Box 64, FIN-00014 University of Helsinki, Finland.
8Odum School of Ecology, 140 East Green Street, University of Georgia, Athens, GA 30602, USA.
9Landscape Ecology, Tvistevägen 48, Department of Ecology and Environmental Science, Umea University, Umea, Sweden SE-90187.
10Smithsonian Institution, Post Office Box 37012, MRC 121, Washington, DC 20013–7012, USA.
11Department of Ecology and Evolutionary Biology, CU Natural History Museum, Campus Box 265, University of Colorado at Boulder, Boulder, CO 80309–0265, USA.
12School of Biological Sciences, Harborne Building, University of Reading, Reading, UK.
13Department of Biological Sciences, 2500 University Drive North West, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
14Department of Atmospheric, Oceanic, and Earth Sciences, George Mason University, Fairfax, VA, USA.

*To whom correspondence should be addressed. E-mail: fasmith@unm.edu

ABSTRACT

The extinction of dinosaurs at the Cretaceous/Paleogene (K/Pg) boundary was the seminal event that opened the door for the subsequent diversification of terrestrial mammals. Our compilation of maximum body size at the ordinal level by sub-epoch shows a near-exponential increase after the K/Pg. On each continent, the maximum size of mammals leveled off after 40 million years ago and thereafter remained approximately constant. There was remarkable congruence in the rate, trajectory, and upper limit across continents, orders, and trophic guilds, despite differences in geological and climatic history, turnover of lineages, and ecological variation. Our analysis suggests that although the primary driver for the evolution of giant mammals was diversification to fill ecological niches, environmental temperature and land area may have ultimately constrained the maximum size achieved.

Received for publication 8 July 2010.
Accepted for publication 18 October 2010.

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Mosaico esplêndido de genes mitocondriais criados pela transferência horizontal e conversão de gene

Gorgeous mosaic of mitochondrial genes created by horizontal transfer and gene conversion

Weilong Hao1,2, Aaron O. Richardson1, Yihong Zheng3, and Jeffrey D. Palmer4

+Author Affiliations

Department of Biology, Indiana University, Bloomington, IN 47405

↵2Present address: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, Canada M5G 1L5.

↵3Present address: College of Life Sciences, Wuhan University, Wuhan 430072, China.

Contributed by Jeffrey D. Palmer, November 1, 2010 (sent for review September 17, 2010)

↵1W.H. and A.O.R. contributed equally to this work.

Abstract

The best known outcome of horizontal gene transfer (HGT) is the introduction of novel genes, but other outcomes have been described. When a transferred gene has a homolog in the recipient genome, the native gene may be functionally replaced (and subsequently lost) or partially overwritten by gene conversion withtransiently present foreign DNA. Here we report the discovery, in two lineages of plant mitochondrial genes, of novel gene combinations that arose by conversion between coresident native and foreign homologs. These lineages have undergone intricate conversion between native and foreign copies, with conversion occurring repeatedly and differentially over the course of speciation, leading to radiations of mosaic genes involved in respiration and intron splicing. Based on these findings, we develop a model—the duplicative HGT and differential gene conversion model—that integrates HGT and ongoing gene conversion in the context of speciation. Finally, we show that one of these HGT-driven gene-conversional radiations followed two additional types of conversional chimerism, namely, intramitochondrial retroprocessing and interorganellar gene conversion across the 2 billion year divide between mitochondria and chloroplasts. These findings expand our appreciation of HGT and gene conversion as creative evolutionary forces, establish plant mitochondria as a premiere system for studying the evolutionary dynamics of HGT and its genetic reverberations, and recommend careful examination of bacterial and other genomes for similar, likely overlooked phenomena.

gene duplication, recombination

Footnotes

4To whom correspondence should be addressed. E-mail:jpalmer@indiana.edu.

Author contributions: W.H., A.O.R., and J.D.P. designed research; W.H., A.O.R., and Y.Z. performed research; W.H., A.O.R., and J.D.P. analyzed data; and W.H., A.O.R., and J.D.P. wrote the paper.

The authors declare no conflict of interest.

Data deposition: The sequences reported in this paper have been deposited in the GenBank database (accession nos. HQ437915–HQ437987).

This article contains supporting information online at

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Identificação de tradução diferencial em estudos de genoma

Identification of differential translation in genome wide studies

Ola Larsson a,1,2, Nahum Sonenberg a, and Robert Nadon b,c,2

-Author Affiliations

aDepartment of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada;
bDepartment of Human Genetics, McGill University, Montreal, Quebec H3A 1B1, Canada; and
cMcGill University and Genome Quebec Innovation Centre, Montreal, Quebec H3A 1A4, Canada

↵1Present address: Department of Oncology–Pathology, Cancer Center Karolinska, Karolinska Institute, R8:01, 171 76 Stockholm, Sweden.

Edited by Peter J. Bickel, University of California, Berkeley, CA, and approved October 26, 2010 (received for review May 20, 2010)

Abstract

Regulation of gene expression through translational control is a fundamental mechanism implicated in many biological processes ranging from memory formation to innate immunity and whose dysregulation contributes to human diseases. Genome wide analyses of translational control strive to identify differential translation independent of cytosolic mRNA levels. For this reason, most studies measure genes’ translation levels as log ratios (translation levels divided by corresponding cytosolic mRNA levels obtained in parallel). Counterintuitively, arising from a mathematical necessity, these log ratios tend to be highly correlated with the cytosolic mRNA levels. Accordingly, they do not effectively correct for cytosolic mRNA level and generate substantial numbers of biological false positives and false negatives. We show that analysis of partial variance, which produces estimates of translational activity that are independent of cytosolic mRNA levels, is a superior alternative. When combined with a variance shrinkage method for estimating error variance, analysis of partial variance has the additional benefit of having greater statistical power and identifying fewer genes as translationally regulated resulting merely from unrealistically low variance estimates rather than from large changes in translational activity. In contrast to log ratios, this formal analytical approach estimates translation effects in a statistically rigorous manner, eliminates the need for inefficient and error-prone heuristics, and produces results that agree with biological function. The method is applicable to datasets obtained from both the commonly used polysome microarray method and the sequencing-based ribosome profiling method.

differential expression, RIP-CHIP, random variance model, translatomics

Footnotes

2To whom correspondence may be addressed. E-mail: ola.larsson@ki.se orrobert.nadon@mcgill.ca.

Author contributions: O.L., N.S., and R.N. designed research; O.L. performed research; O.L. analyzed data; and O.L., N.S., and R.N. wrote the paper.

The authors declare no conflict of interest.

This article is a PNAS Direct Submission.

This article contains supporting information online at

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Bolsa Dra. Ruth Cardoso tem nova chamada

30/11/2010

Agência FAPESP – O Programa de Bolsa Dra. Ruth Cardoso abriu seleção de propostas para sua terceira edição. As inscrições podem ser feitas até o dia 17 de janeiro de 2011. A iniciativa oferece apoio à participação de professores e pesquisadores brasileiros das áreas de ciências humanas e sociais nas atividades da Universidade de Columbia, em Nova York, Estados Unidos.

O Programa é uma parceria da Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) e da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Capes) com a Universidade de Columbia e a Comissão para o Intercâmbio Educacional entre os Estados Unidos da América e o Brasil (Fulbright).

Programa para seleção de professor ou pesquisador visitante na Universidade Columbia, nos Estados Unidos, tem inscrições abertas até 17 de janeiro (Wikimedia)

Entre os objetivos do programa estão destacar no meio universitário e de pesquisa dos Estados Unidos a atuação de cientistas brasileiros em instituições do país nas áreas de ciências humanas e sociais e promover a aproximação, o diálogo e aprofundamento no conhecimento mútuo das duas culturas e sociedades.

A bolsa honra a memória da professora Ruth Corrêa Leite Cardoso, ex-bolsista da Comissão Fulbright na Universidade Columbia em 1988 e personalidade de destacada atuação na cena acadêmica brasileira, em particular nas ciências humanas e sociais.

O programa prevê a concessão de uma bolsa por ano. A bolsa tem o valor mensal de US$ 5 mil e será concedida por um período de até nove meses. O selecionado também receberá auxílio instalação de US$ 2 mil, seguro- saúde, passagem aérea de ida e volta em classe econômica promocional e moradia no campus da Universidade Columbia, em Nova York, em apartamento de um dormitório ou equivalente.

O bolsista também terá acesso às instalações e serviços da Universidade Columbia – escritório, internet, laboratórios e bibliotecas – e demais meios necessários à efetiva consecução das atividades de docência ou de pesquisa.

Os candidatos deverão ter concluído doutorado antes de 2007, possuir nacionalidade brasileira e não ter nacionalidade norte-americana e estar credenciado como docente e orientador em programa de pós-graduação reconhecido pela Capes.

Deverão também, entre outros requisitos, dedicar-se em regime integral às atividades acadêmicas, que devem incluir a docência, orientação ou co-orientação de dissertações ou teses e/ou a participação em projetos de pesquisa em ciências humanas e sociais com ênfase nas áreas de antropologia, ciência política, sociologia e história do Brasil.

A inscrição deve ser feita pela internet, com o preenchimento em inglês do formulário de inscrição, um syllabus do curso proposto com no máximo dez páginas e três cartas de recomendação em inglês, além de um currículo atualizado em português (na Plataforma Lattes), um currículo resumido em inglês e o projeto de pesquisa a ser desenvolvido na Universidade de Columbia.

Mais informações: www.fapesp.br/ruthcardoso

Nomenklatura científica: a próxima vítima do WikiLeaks

Fontes seguras e próximas ao WikiLeaks afirmam que, brevemente, muito em breve, muita coisa podre que a Nomenklatura científica encobre virá à tona.

Será que vai ser sobre a maneira como a Akademia trata a questão da teoria da evolução através da seleção natural de Darwin? Ou somente os casos de plágio? Ou a manutenção de duas fraudes e evidências científicas distorcidas para corroborar o fato, Fato, FATO da evolução nos livros didáticos de biologia do ensino médio aprovados despudoradamente pelo MEC/SEMTEC/PNLEM? Ou alguns desvios de verbas de pesquisas? 


É gente, também há disso na Nomenklatura científica. Gente com o rabo preso, envolvido em falcatruas, e com a mão na cumbuca, uma hora dessas deve estar tremendo de medo (???), ou torcendo para que não seja verdade.

Que venga las denúncias de WikiLeaks sobre la Nomenklatura científica. 

Não vai sobrar pedra sobre pedra no templo de Down. Duela a quien duela!!!


Fui, nem sei por que, pensando, que quem tem, tem medo...

Seleção natural como um paradigma de oportunismo em biologia

JOURNAL OF BIOECONOMICS
DOI: 10.1007/s10818-010-9094-5

Natural selection as a paradigm of opportunism in biology

Joseph Esfandiar Hannon Bozorgmehr


Abstract

The success of extant species is largely due to their ability to adapt in the face of constantly changing environmental conditions. Natural selection is the biological mechanism that takes advantage of opportunities to promote spontaneous variations and facilitate evolutionary development. The character of this biological opportunism is considered here, placing it firmly within the context of various social and economic principles—notably individualism, industrialism, utilitarianism and consequentialism—that have characterised the philosophy of the modern era. However, this purely opportunistic approach, and its myopic emphasis on immediate problem solving, has serious shortcomings within both life and business practice. These are examined here in contrast to some of the alternative approaches found in biology and economics theory. The nature and relationship of function to utility in biology is also given particular consideration, as is the issue of incrementalism in the development of complex adaptive features. The methodological reductionism at the heart of evolutionary biology certainly does offer insightful empirical results reported in the scientific literature. Nonetheless, natural selection is observed to be a purely reflexive mechanism and not one capable of producing the kind of innovation necessary for the more revolutionary changes in an organism’s systems.

Keywords Natural selection - Reductionism - Utility - Opportunism - Incrementalism

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NOTA CAUSTICANTE DESTE BLOGGER:

Destaco duas frases deste abstract:

Natural selection is the biological mechanism that takes advantage of opportunities to promote spontaneous variations and facilitate evolutionary development.
...

Nonetheless, natural selection is observed to be a purely reflexive mechanism and not one capable of producing the kind of innovation necessary for the more revolutionary changes in an organism’s systems.

Se, e bota se nisso, a seleção natural é o mecanismo biológico que tira vantagem das oportunidades em promover as variações espontâneas e facilitar o desenvolvimento evolucionário, como que a seleção natural é incapaz de produzir o tipo de inovação necessária para as mudanças mais revolucionárias nos sistemas de um organismo? 

Traduzindo em graúdos: a seleção natural é incapaz de produzir MACROEVOLUÇÃO. Mas é a macroevolução que corrobaria o fato, Fato, FATO da evolução no contexto de justificação teórica. Ou eu estou errado??? Chamem os biólogos comprometidos com uma ciência objetiva, e o que será que eles dirão???

Um mecanismo bioquímico para mutações não aleatórias e evolução

segunda-feira, novembro 29, 2010

JOURNAL OF BACTERIOLOGY,

0021-9193/00/$04.0010

June 2000, p. 2993–3001 Vol. 182, No. 11

Copyright © 2000, American Society for Microbiology. All Rights Reserved.

A Biochemical Mechanism for Nonrandom Mutations and Evolution

BARBARA E. WRIGHT*

Division of Biological Sciences, The University of Montana, Missoula, Montana

As this minireview is concerned with the importance of the environment in directing evolution, it is appropriate to remember that Lamarck was the first to clearly articulate a consistent theory of gradual evolution from the simplest of species to the most complex, culminating in the origin of mankind (71). He published his remarkable and courageous theory in 1809, the year of Darwin’s birth. Unfortunately, Lamarck’s major contributions have been overshadowed by his views on the inheritance of acquired characters. In fact, Darwin shared some of these same views, and even Weismann (106), the father of neo-Darwinism, decided late in his career that directed variation must be invoked to understand some phenomena, as random variation and selection alone are not a sufficient explanation (71). This minireview will describe mechanisms of mutation that are not random and can accelerate the process of evolution in specific directions. The existence of such mechanisms has been predicted by mathematicians (6) who argue that, if every mutation were really random and had to be tested against the environment for selection or rejection, there would not have been enough time to evolve the extremely complex biochemical networks and regulatory mechanisms found in organisms today. Dobzhansky (21) expressed similar views by stating “The most serious objection to the modern theory of evolution is that since mutations occur by ‘chance’ and are undirected, it is difficult to see how mutation and selection can add up to the formation of such beautifully balanced organs as, for example, the human eye.”

The most primitive kinds of cells, called progenotes by Woese (108), were undoubtedly very simple biochemically with only a few central anabolic and catabolic pathways. Wächterhäuser (103) theorizes that the earliest metabolic pathway was a reductive citric acid cycle by which carbon fixation occurred (64). At that point in time, some four billion years ago, how did the additional, more complex metabolic pathways found in even the simplest prokaryotes evolve? For that matter, how are they evolving today? As pointed out by Oparin (79), it is inconceivable that a self-reproducing unit as complicated as a nucleoprotein could suddenly arise by chance; a period of evolution through the natural selection of organic substances of ever-increasing degrees of complexity must intervene. Horowitz (40) suggests a plausible scheme by which biosynthetic pathways can evolve from the successive depletion and interconversion of related metabolites in a primitive environment, as the rich supply of organic molecules is consumed by a burgeoning population of heterotrophs. Thus, a possible scenario begins with the starvation of a self-replicating unit for its precursor, metabolite A, utilized by enzyme 1 encoded by gene 1. When metabolite A is depleted, a mutation in a copy of gene 1 gives rise to gene 2 and allows enzyme 2 to use metabolite B by converting it to metabolite A. Then metabolite B is depleted, obtained from metabolite C, and so on, as an increasingly complex biochemical pathway evolves. In fact, there are examples in which a similar series of events can actually be observed in the laboratory, for example, involving enzymes that are “borrowed” from existing pathways, via regulatory mutations, to establish new pathways (75). 

The starvation conditions that may initiate a series of events such as those described above target the most relevant genes for increased rates of transcription, which in turn increase rates of mutation (111). Transcriptional activation can result from the addition of a substrate or from the removal of a repressor or an end product inhibitor. The latter mechanism, called derepression, occurs in response to starvation for an essential substrate or for an end product that represses its own synthesis by feedback inhibition. Since evolution usually occurs in response to stress (41), transcriptional activation via derepression is the main focus of this minireview.

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NOTA CAUSTICANTE DESTE BLOGGER:

Eu sempre chamei aqui o Darwinismo de smorgasbord teórico -- um self-service de pratos variados para os diversos paladares epistêmicos -- um variado conglomerado de ideias evolucionárias não muito diferente das ideias evolucionárias já discutidas pelos antigos filosófos gregos. 



E o fato, Fato, FATO da evolução não é tão corroborado no contexto de justificação teórico assim como a lei da gravidade e que a Terra gira em redor do Sol? Não é a pedra fundamental da biologia???


Nada mais falso!!! Darwin acertou no varejo evolucionário e errou no atacado evolucionário. Um infante teórico que copiou ideias evolucionárias de seus precursores. Só isso de revolucionário. Copiou e nem crédito deu a quem de direito. Estou certo, ou estou errado? Com a palavras os historiadores de ciência.

Refuah - Yaakov Shwekey com Boruch Levine



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Para, por e com Israel, sempre!

Techi Nafshi - Eli Laufer



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Para, por e com Israel, sempre!

Um retardador biológico de quarto de comprimento de onda com excelente acromaticidade na região visível de comprimento de onda

Nature Photonics 3, 641 - 644 (2009) 
Published online: 25 October 2009 | doi:10.1038/nphoton.2009.189

Subject Category: Biophotonics

A biological quarter-wave retarder with excellent achromaticity in the visible wavelength region

N. W. Roberts1,2, T.-H. Chiou3, N. J. Marshall3 & T. W. Cronin4

Abstract

Animals make use of a wealth of optical physics to control and manipulate light, for example, in creating reflective animal colouration1, 2, 3 and polarized light signals4. Their precise optics often surpass equivalent man-made optical devices in both sophistication and efficiency5. Here, we report a biophysical mechanism that creates a natural full-visible-range achromatic quarter-wave retarder in the eye of a stomatopod crustacean. Analogous, man-made retardation devices are important optical components, used in both scientific research and commercial applications for controlling polarized light. Typical synthetic retarders are not achromatic, and more elaborate designs, such as, multilayer subwavelength gratings or bicrystalline constructions, only achieve partial wavelength independence6. In this work, we use both experimental measurements and theoretical modelling of the photoreceptor structure to illustrate how a novel interplay of intrinsic and form birefringence results in a natural achromatic optic that significantly outperforms current man-made optical devices.

Photon Science Institute, School of Physics and Astronomy, University of Manchester, Manchester M13 9PL, UK

School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, UK

Sensory Neurobiology Group, School of Biomedical Sciences and Queensland Brain Institute, The University of Queensland, Brisbane, Queensland 4072, Australia

Department of Biological Sciences, University of Maryland Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250, USA

Correspondence to: N. W. Roberts1,2 e-mail: nicholas.roberts@bristol.ac.uk

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NOTA DESTE BLOGGER:

Pobre Darwin, ele era totalmente ignorante desta complexidade visual, mas muito honesto em dizer que só em pensar neste sistema lhe dava calafrios. Mesmo assim, especulou a transmutação das espécies, algo muito mais complexo do que um simples olho...

Visão de polarização circular em um crustáceo estomatópode: mero acaso, fortuita necessidade ou design inteligente?

Current Biology 18, 429–434, March 25, 2008

Circular Polarization Vision in a Stomatopod Crustacean

Tsyr-Huei Chiou,1,4 Sonja Kleinlogel,2,4,5 Tom Cronin,1 Roy Caldwell,3 Birte Loeffler,2,6 Afsheen Siddiqi,1 Alan Goldizen,2 and Justin Marshall2,*

1Department of Biological Sciences
University of Maryland Baltimore County
1000 Hilltop Circle
Baltimore, Maryland 21250

2Sensory Neurobiology Group
Vision Touch and Hearing Research Centre
School of Biomedical Sciences and Queensland Brain Institute
The University of Queensland
Brisbane, Queensland 4072
Australia

3Department of Integrative Biology
University of California, Berkeley
3060 Valley Life Sciences Building #3140
Berkeley, California 94720-3140


Summary

We describe the addition of a fourth visual modality in the animal kingdom, the perception of circular polarized light. Animals are sensitive to various characteristics of light, such as intensity, color, and linear polarization [1, 2]. This latter capability can be used for object identification, contrast enhancement, navigation, and communication through polarizing reflections [2–4]. Circularly polarized reflections from a few animal species have also been known for some time [5, 6]. Although optically interesting [7, 8], their signal function or use (if any) was obscure because no visual system was known to detect circularly polarized light. Here, in stomatopod crustaceans, we describe for the first time a visual system capable of detecting and analyzing circularly polarized light. Four lines of evidence—behavior, electrophysiology, optical anatomy, and details of signal design—are presented to describe this new visual function. We suggest that this remarkable ability mediates sexual signaling and mate choice, although other potential functions of circular polarization vision, such as enhanced contrast in turbid environments, are also possible [7, 8]. The ability to differentiate the handedness of circularly polarized light, a visual feat never expected in the animal kingdom, is demonstrated behaviorally here for the first time.

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NOTA DESTE BLOGGER:

A seleção natural, o mecanismo evolucionário importante de Charles Darwin, mas não o único (tem de A a Z), é cego, aleatório e não teleológico nas suas proezas criativas quando lida com quaisquer formas vivas. Ué, e aqui no caso do sistema visual deste crustáceo estomatópode: object identification, contrast enhancement, navigation, and communication through polarizing reflections são todas funções télicas e, eu não pude resistir, sinais de inteligência detectados na natureza pelos pesquisadores através de QUATRO LINHAS DE EVIDÊNCIAS: behavior, electrophysiology, optical anatomy, and details of signal design.


Darwin, limitações teóricas e tecnológicas, à parte, já sentia calafrios com a visão humana, imagine se soubesse desta visão de polarização circular em um simples camarão.

Fui, nem sei por que pensando: o design é real na natureza, mas tem cegos como Richard Dawkins que são mais cegos do que os demais...