quinta-feira, 10 de novembro de 2011

A próxima síntese evolucionária: de Lamarck e Darwin à variação genômica e biologia de sistemas + O dilema do darwinista + Um fóssil de ácaro forético pequeno recuperado por tomografia computadorizada de contraste de fase de raios-X

Desafiando a Nomenklatura Científica





Posted: 10 Nov 2011 10:55 AM PST


The next evolutionary synthesis: from Lamarck and Darwin to genomic variation and systems biology

Jonathan BL Bard

Correspondence: Jonathan BL Bard j.bard@ed.ac.uk

Cell Communication and Signaling 2011, 9:30

doi:10.1186/1478-811X-9-30Published: 3 November 2011

Abstract (provisional)

The evolutionary synthesis, the standard 20th century view of how evolutionary change occurs, is based on selection, heritable phenotypic variation and a very simple view of genes. It is therefore unable to incorporate two key aspects of modern molecular knowledge: first is the richness of genomic variation, so much more complicated than simple mutation, and second is the opaque relationship between the genotype and its resulting phenotype. Two new and important books shed some light on how we should view evolutionary change now. "Evolution: a view from the 21st century" by J.A. Shapiro (2011, FT Press Science, New Jersey, USA. pp. 246) examines the richness of genomic variation and its implications. "Transformations of Lamarckism: from Subtle Fluids to Molecular Biology" edited by S.B. Gissis & E. Jablonka (2011, MIT Press, Cambridge, USA. pp. 457) includes some 40 papers that anyone with an interest in the history of evolutionary thought and the relationship between the environment and the genome will want to read. This review discusses both books within the context of contemporary evolutionary thinking and points out that neither really comes to terms with today's key systems-biology question: how does mutation-induced variation in a molecular network generate variation in the resulting phenotype?

The complete article is available as a provisional PDF

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NOTA E PERGUNTA INDISCRETA DESTE BLOGGER:

Eu queria ver a cara de alguns dos meus amigos biólogos evolucionistas, da Galera dos meninos e meninas de Darwin que ouviram de mim que uma grande, eminente e iminente mudança paradigmática em biologia evolucionária, e eles disseram que eu tinha embarcado numa canoa furada, que eu estava falando bobagem.

E agora gente? Como é bom ser vindicado em ciência, especialmente ser vindicado pelos evolucionistas. Todo o mundo já sabe, qua Stephen Jay Gould, que a teoria da evolução através da seleção natural e n mecanismos evolucionários está mais furada do que queijo suiço.

Não ensinar isso em salas de aulas do ensino médio é DESONESTIDADE ACADÊMICA, 171 Epistêmico, pois vocês da Nomenklatura científica que Darwin não é corroborado no contexto de justificação teórica e sonegam essas informações dos estudantes e do público. E a Grande Mídia, qual amante que não pode aparecer de braços dados, INTENCIONALMENTE evita abordar a questão do status epistêmico da teoria da evolução: relação incestuosa!!!

Coisa mais ridícula gente! Essas informações que posto aqui neste blog estão ao alcance de qualquer pessoa com apenas um toque no teclado de um computador.

Ao debate Srs., a maior ideia que toda a humanidade já teve, a teoria científica tão certa e confirmada como a lei da gravidade, não é assim nenhuma Brastemp epistêmica.

Que venga la nueva teoría de la evolución: a SÍNTESE EVOLUTIVA AMPLIADA. Espere sentado, pois a Nomenklatura científica somente apresentará a nova teoria em 2020.

Fui, nem sei por que, feliz da vida por saber ter sido vindicado por mais um evolucionista!!!


Posted: 10 Nov 2011 06:11 AM PST
10 November 2011

The Darwinist’s Dilemma

jbarham


Time was, when teaching correct moral values to young people was universally regarded as a primary responsibility of educators, at all levels of the educational system.

Today, we tell our schoolchildren there is nothing absolutely right or absolutely wrong, only behavior that is “appropriate” or “inappropriate” to particular situations. I say “we” tell them this, because this is what they are taught in America’s public schools, and we are all collectively responsible for what goes on there.

Just business as usual, I suppose—from the secular liberal perspective. But, then, why do the selfsame folks who celebrate moral relativism in the classroom suddenly become absolutist when it comes to teaching evolution?

Of course, the question of what should be permissible to teach in the public schools is not a simple one. It is a multi-dimensional problem, one prominent dimension of which is clearly that of religion. I take it for granted that most Americans do not want their tax dollars to pay for lessons on the finer points of the Book of Genesis—or the Book of Mormon or the Quran or the Rig Veda or the Dao De Jing—at least not outside of comparative religion class. But the attempt of the professional Darwin lobby to paint all critiques of contemporary neo-Darwinism as religiously motivated is a travesty.

I used to teach a section on “evolutionary ethics” in an Introduction to Philosophy course at a well-known American university. In this section, I always presented some of the many widely discussed conceptual difficulties with the theory of natural selection, but I breathed not one word about religion. And yet, if I were to teach a similar course in a high school in the state of Pennysylvania today, I might be prosecuted at law, pursuant to theKitzmiller v. Dover decision. (I wonder how many years you get for mentioning tautology. I hear they really throw the book at you if you bring up petitio principii.)

The absurdity of a state-enforced scientific doctrine is a scandal that scientists ought to be the first to protest. We are talking about science, for goodness’ sake—that most corrigible of all fallible human endeavors! Scientifc ideas change—and generally improve—over time. On the Origin of Species was not inscribed on stone tablets and Charles Darwin was not Moses. And yet, when Kitzmiller quashed all discussion of the many problems with natural selection in the public schools, presumably for all time to come, the professional Darwin lobby congratulated itself on a great victory.

Religion aside, what actual arguments are there in favor of indoctrinating all American schoolchildren with an outdated and one-sided version of evolutionary theory?

One frequently hears two sorts of claims advanced. Both of them are either exaggerated or flat-out unsupported.

Here is the first one:

(1) Evolutionary biology is critical for the advance of medicine.

This attitude is well represented by the following statement, posted by a group called the Colorado Evolution Response Team on their web site:


Understanding evolution is critical to research and advances in medicine, agriculture, public health, ecology, botany, zoology, etc. Curing cancer will require that we apply the lessons of evolution. Even scientific endeavors far removed from biology depend on an understanding of evolutionary processes.

Note that this is a pragmatic argument. We ought to teach natural selection in the schools because it will have practical benefits in all these areas.


Now, it is true—to take the most important case—that we need to know about the ability of populations of bacteria to develop resistance to certain antibiotics. But it is arguable whether this phenomenon has anything much to do with evolution. Even if it does, what is important for medical research is not proving that macroevolution (the origin of entirely new species possessing significantly different bodily traits) flows from microevolution (adaptive changes in the proportional distribution of a preexisting spectrum of traits within a population).

Rather, what is important for medical research is understanding how bacterial resistance and other such phenomena actually occur at the molecular level. For example, we now know—entirely contrary to the predictions of neo-Darwinian theory—that bacterial resistance is not primarily a matter of random genetic mutation and natural selection, but instead is a functional (goal-directed) process involving the transfer of genetic particles (plasmids) from one bacterium to another.

And bacterial resistance to antibiotics is the strongest argument the Darwinists have for teaching evolution. The other ones are mainly based on unsupported speculations (known by the professional term of art, “Just-So Stories”), which even if they were correct would have few if any therapeutic implications. For example, what we most likely need in order to crack the problem of cancer is to understand how global cellular and physiological control is achieved, in general, as it is very plausible that cancer is primarily a tissue-level, not a genetic, disease. The historical path by which multicellularity first arose 575 mya, while an interesting question in itself, is of small practical importance for understanding cancer today.


To summarize, Darwin’s apologists conflate knowing the history of an organism with knowing how the organism works. The former certainly has its own claim on our intellectual curiosity, but providing practical insight into the vastly intricate and still quite mysterious workings of living things forms no part of it.

The second claim Darwinists frequently advance to justify proselytizing the populace at large is this:

2. Evolutionary biology is critical for the progress of humanity.

This bold claim was spelled out with unusual clarity in a recent essay in The New York Review of Books by Duke University ecologist John Terborgh. He entitled his piece, modestly, “Can Our Species Escape Destruction?

Here is the way he articulates the second claim:

Rejection of evolution presents a huge obstacle to the future well-being of humanity. A deep understanding of the “selfish gene” [why the scare quotes, Professor Terborgh?] sheds light on many facets of human behavior that the value systems of our society would regard as both positive and negative. Such understanding can help explain why people are clannish and often compulsively greedy, why married men philander, and why we are so prone to violence as a means of resolving disputes. On the positive side, the science of evolution can help explain why we are mostly monogamous, why mothers obsessively cherish their babies, why we tend to care for our relatives more than strangers, even why we strive to succeed economically.

I’m convinced that we won’t have lasting harmony in our global society until we recognzie the facts and implications of evolutionary biology and put them to work in creating laws to counteract our most unfortunate tendencies, tendencies that were advantageous during our hunter-gatherer origins but that have become decidedly disadvantageous in a highly integrated society of strangers.

These claims are breathtaking in their fatuity and their incoherence.

First, if Terborgh is concerned about bringing such human traits as greed and sexual betrayal and violence to the attention of the nation’s young—well, I can only applaud him. For, to condemn these things is to make a moral judgment—to commit oneself to the existence of right and wrong. I do humbly submit, however, that we would be infinitely better off as a society if Junior spent his time studying Dombey and Son and Anna Karenina andCrime and Punishment than some textbook in evolutionary biology.

So much for the fatuity of his argument. As for the incoherence, the problem lies in the fact that Professor Terborgh claims that some human traits are positive and others are negative—presumably, he means in a moral sense—yet his theory gives him no way of distinguishing between them. Men evolved to philander; women evolved to stay at home and nurture (apparently, Professor Terborgh does not watch enough TV). There is no way to label one of these traits as “bad” and the other as “good” from within the Professor’s own conceptual framework. Rather, he helps himself to these concepts quite inconsistently.

Terborgh is not alone in doing this, of course. The majority of Darwinists who comment on public affairs do the same thing. Of course, most of them are not trained philosophers, and perhaps do not understand that you cannot both say that human behaviorral propensities have arisen through a purposeless and meaningless natural process and that some of these traits are good while others are bad. Moreover, even the majority of Darwinist philosophers balk at following the logic of selection theory through to its conclusion. This should not surprise us. After all, it is powerfully counterintuitive that our human life of purpose, value, and meaning should be nothing but an illusion.

But that is clearly what Darwinian theory implies. One Darwinist thinker who understands this and does not shrink from saying so openly is Duke philosopher Alex Rosenberg.

He writes:

Even when you get to the locus classicus of purposeful phenomena in human cognition and its consequences in action, natural selection explains both capacities and performances in a way that dispenses with purpose even here. Darwinism thus puts the capstone on a process which sicne Newton’s time has driven teleology to the explanatory sidelines. In short it has made Darwinians into metaphysical Nihilists denying that there is any meaning or purpose to the universe, its contents and its cosmic history. But in making Darwinians into metaphysical nihilists, the solvent algorithm [of natural selection] should have made them into ethical nihilists too. For intrinsic values and obligations make sense only against the background of purposes, goals, and ends which are not merely instrumental. But the leading Darwinian philosophers have shied away from this implication . . .(1)

The Darwinist, if he cares about logical consistency, finds himself caught on the horns of a dilemma:

Either human propensities and behaviors are the product of natural selection, in which case it is idle to praise or blame them. Or else at least some human traits really are deserving of praise and blame, in which case it is idle to invoke natural selection to explain them.

If Darwinists publicly opt for the former horn of this dilemma, I doubt that the American public will wish to turn over the education of its children to them. If they opt for the second horn, American public education has no need of them.

* * *

It is not necessary to invoke religious faith to see what is wrong with Darwinism—which itself has so many of the trappings of an ideology—and why it is a mistake to mandate the teaching of Darwinism in the public schools by judicial fiat.

The heart of the problem lies in the foundations of biology, in our ignorance of how such a physical system as a living cell is even possible. The problem touches on many deep philosophical and scientific enigmas, involving what it means for a material thing to have interests, needs, and goals—what it means for a physical system to be an agent.

There is no reason, in my view, why these matters must forever lie beyond the horizon of scientific investigation. But in order to bring the normativity of life into science, science itself will have to be transformed beyond present recognition. And that cannot happen as long as neo-Darwinian thinking is blocking the path of scientific progress.

Theodosius Dobzhansky famously said that “Nothing in biology makes sense except in the light of evolution.” The deeper truth is this: “Nothing in biology makes sense except in the light of teleology.”

It is only by acknowledging the role that purpose, value, and meaning—in a word, agency—play in biological matter and confronting this phenomenon head-on as the fundamental scientific problem that it is, rather than sweeping it under the rug, that biology will be able to push past the scientific roadblock of neo-Darwinism.

And it is only by bringing the normative dimension of life—as a real, sui generis phenomenon—under the aegis of science that the Darwinist can extricate himself from the horns of his dilemma.
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(1) Sommers, Tamler and Alex Rosenberg, “Darwin’s Nihilistic Idea: Evolution and the Meaninglessness of Life,” Biology and Philosophy, 2003, 18: 653–668; p. 653.

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Posted: 10 Nov 2011 03:09 AM PST
A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography

Jason A. Dunlop1,*, Stefan Wirth1, David Penney2, Andrew McNeil3, Robert S. Bradley3, Philip J. Withers3 and Richard F. Preziosi2

Author Affiliations

1Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity, Humboldt University Berlin, 10115 Berlin, Germany
2Faculty of Life Sciences, University of Manchester, Manchester M13 9PF, UK
3Henry Moseley X-ray Imaging Facility, School of Materials, University of Manchester, Manchester M1 7HS, UK

*Author for correspondence (jason.dunlop@mfn-berlin.de).

Abstract

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44–49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers.

Acariformes, Astigmata, Histiostomatidae, Acaridae, amber, Eocene

Received September 23, 2011.
Accepted October 18, 2011.
This journal is © 2011 The Royal Society

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