quinta-feira, dezembro 14, 2006

Entropia Genética: primeiras impressões.

Há umas semanas o Jónatas Machado teve a amabilidade de me oferecer o livro «Genetic Entropy & The Mistery of the Genome», do John Sanford, o que me deu a oportunidade de ficar a conhecer melhor os argumentos mais recentes do movimento criacionista.

O livro é um pouco estranho. Pretende ser uma divulgação científica e objectiva, mas todos os capítulos começam com um subtítulo que diz «Newsflash», no meio do texto há frases sublinhadas, frases a negrito, e muitos pontos de exclamação. A sensação é de estar a ouvir um pregador emocionado a exortar os seus seguidores em vez de uma explicação científica. Também incomoda a forma como o livro subestima a capacidade de compreensão do leitor. Quando o autor diz que as instruções para fazer um carrinho de mão caberiam num livro, temos um desenho de um carrinho com um livro em cima. Quando o autor fala da fábula da princesa que sentia uma ervilha através do colchão, lá vem o desenho da princesa em cima de uns colchões e ervilhas espalhadas à volta.

Mas interessa mais o conteúdo que a forma. A proposição central do livro é que o nosso genoma está a degradar-se pela acumulação de mutações. Todos nascemos com mutações e, segundo Sanford, a selecção natural não consegue eliminar um número suficiente para prevenir a destruição da informação no genoma humano. Para isto Sanford invoca o custo de selecção, um termo criado por Haldane para designar a quantidade de mortes (ou esterilidade) necessária numa população para que um alelo (um gene de um tipo) substitua outro.

Suponhamos que todos os indivíduos de uma população têm o gene A, e surge um mutante com a variante B deste gene. Para que a população fique toda com o gene B é preciso que muitos indivíduos com o gene A morram sem descendentes. Como só uma parte da população pode ser eliminada a cada geração, e como em geral vão morrer também indivíduos com o gene B, é preciso muitas gerações para que o gene B substitua o gene A na população. Haldane estimou que este processo numa espécie como a nossa demoraria cerca de 300 gerações.

Mas isto é muito diferente do problema de eliminar mutações novas. Quando surge uma mutação deletéria num indivíduo basta que esse indivíduo morra sem descendentes para que a mutação seja eliminada da população. É surpreendente que Sanford tenha confundido o custo de eliminar uma mutação nova com o custo de substituir um gene presente em toda a população.

Sanford também assume que a proporção de mutações prejudiciais é uma constante, mas isso é falso. Imaginemos um o organismo com os melhores genes possíveis para todos os atributos. Adão, para os criacionistas; a criação perfeita (antes de perder a costela). Neste qualquer mutação será prejudicial. Mas conforme os descendentes vão acumulando imperfeições vai aumentando a probabilidade de uma mutação aleatória melhorar algo, quanto mais não seja por reverter um gene mutante ao gene original.

Na realidade não há uma degradação constante mas um equilíbrio dinâmico. Mutações aleatórias introduzem um grande numero de imperfeições e algumas melhorias ocasionais. A selecção natural elimina defeitos graves rapidamente faz com que as melhorias se propaguem lentamente pela população. Alterações que têm um impacto pequeno demais simplesmente se acumulam ou desaparecem ao acaso (a evolução neutra proposta por Kimura e outros). E é verdade que a distribuição de genes pela população está em constante evolução. Não há nenhum processo natural que fixe para sempre o genoma de uma população. Mas é só o criacionismo que exige que o Homem seja o produto final duma criação perfeita. Para a teoria da evolução somos apenas um passo num deambular sem fim.

O que podemos esperar deste equilíbrio dinâmico é uma grande diversidade de características e indivíduos. Uns serão mais fortes, outros mais rápidos, outros mais atraentes, e assim por diante. Todos terão alguns defeitos, e alguns terão muitos defeitos. Exactamente o que observamos em qualquer população.

Nos próximos posts vou elaborar melhor alguns pontos que o Jónatas Machado sugeriu e que são discutidos neste livro. Mas como apreciação geral posso dizer que este livro sofre dos mesmos problemas que todos os argumentos criacionistas que conheço: uma má compreensão da teoria da evolução, e uma análise incompleta e tendenciosa dos factos.

4 comentários:

  1. Que tal uma pequena incursão pelos argumumentos evolucionistas? A avaliar pela avaliação do Ludwig será certamente uma lufada de ar fresco!

    It is, however, very difficult to establish the precise lines of descent,
    termed phylogenies, for most organisms." (Ayala, F. J. and Valentine J. W.,
    Evolving: The Theory and Process of Organic Evolution, 1978, p. 230)


    "Undeniably, the fossil record has provided disappointingly few gradual series.
    The origins of many groups are still not documented at all." (Futuyma, D.,
    Science on Trial: The Case for Evolution, 1983, p. 190-191)


    "There is still a tremendous problem with the sudden diversification of
    multi-cellular life. There is no question about that. That's a real
    phenomenon." (Niles Eldredge, quoted in Darwin's Enigma: Fossils and Other
    Problems by Luther D. Sunderland, Master Book Publishers, Santee, California,
    1988, p. 45)


    "Whatever ideas authorities may have on the subject, the lungfishes, like every
    other major group of fishes that I know, have their origins firmly based in
    nothing." (Quoted in W. R. Bird, _The Origin of Species Revisited_ [Nashville:
    Regency, 1991; originally published by Philosophical Library, 1987], 1:62-63)


    "The main problem with such phyletic gradualism is that the fossil record
    provides so little evidence for it. Very rarely can we trace the gradual
    transformation of one entire species into another through a finely graded
    sequence of intermediary forms." (Gould, S.J. Luria, S.E. & Singer, S., A View
    of Life, 1981, p. 641)


    "It should come as no surprise that it would be extremely difficult to find a
    specific fossil species that is both intermediate in morphology between two
    other taxa and is also in the appropriate stratigraphic position." (Cracraft,
    J., "Systematics, Comparative Biology, and the Case Against Creationism," 1983,
    p. 180)


    "Most families, orders, classes, and phyla appear rather suddenly in the fossil
    record, often without anatomically intermediate forms smoothly interlinking
    evolutionarily derived descendant taxa with their presumed ancestors."
    (Eldredge, N., 1989, Macro-Evolutionary Dynamics: Species, Niches, and Adaptive
    Peaks, McGraw-Hill Publishing Company, New York, p. 22)


    "Species that were once thought to have turned into others have been found to
    overlap in time with these alleged descendants. In fact, the fossil record does
    not convincingly document a single transition from one species to another."
    (Stanley, S.M., The New Evolutionary Timetable: Fossils, Genes, and the Origin
    of Species, 1981, p. 95)


    "Many fossils have been collected since 1859, tons of them, yet the impact they
    have had on our understanding of the relationships between living organisms is
    barely perceptible. ...In fact, I do not think it unfair to say that fossils,
    or at least the traditional interpretation of fossils, have clouded rather than
    clarified our attempts to reconstruct phylogeny." (Fortey, P. L.,
    "Neontological Analysis Versus Palaeontological Stores," 1982, p. 120-121)


    "Indeed, it is the chief frustration of the fossil record that we do not have
    empirical evidence for sustained trends in the evolution of most complex
    morphological adaptations." (Gould, Stephen J. and Eldredge, Niles, "Species
    Selection: Its Range and Power," 1988, p. 19)


    "The paleontological data is consistent with the view that all of the currently
    recognized phyla had evolved by about 525 million years ago. Despite half a
    billion years of evolutionary exploration generated in Cambrian time, no new
    phylum level designs have appeared since then." ("Developmental Evolution of
    Metazoan Body plans: The Fossil Evidence," Valentine, Erwin, and Jablonski,
    Developmental Biology 173, Article No. 0033, 1996, p. 376)


    "Many 'trends' singled out by evolutionary biologists are ex post facto
    rendering of phylogenetic history: biologists may simply pick out species at
    different points in geological time that seem to fit on some line of
    directional modification through time. Many trends, in other words, may exist
    more in the minds of the analysts than in phylogenetic history. This is
    particularly so in situations, especially common prior to about 1970, in which
    analysis of the phylogenetic relationships among species was incompletely or
    poorly done." (Eldredge, Niles, Macro-Evolutionary Dynamics: Species, Niches,
    and Adaptive Peaks, 1989, p. 134)


    "The Eldredge-Gould concept of punctuated equilibria has gained wide acceptance
    among paleontologists. It attempts to account for the following paradox: Within
    continuously sampled lineages, one rarely finds the gradual morphological
    trends predicted by Darwinian evolution; rather, change occurs with the sudden
    appearance of new, well-differentiated species. Eldredge and Gould equate such
    appearances with speciation, although the details of these events are not
    preserved. ...The punctuated equilibrium model has been widely accepted, not
    because it has a compelling theoretical basis but because it appears to resolve
    a dilemma. Apart from the obvious sampling problems inherent to the
    observations that stimulated the model, and apart from its intrinsic
    circularity (one could argue that speciation can occur only when phyletic
    change is rapid, not vice versa), the model is more ad hoc explanation than
    theory, and it rests on shaky ground." (Ricklefs, Robert E., "Paleontologists
    Confronting Macroevolution," Science, vol. 199, 1978, p. 59)


    "Few paleontologists have, I think ever supposed that fossils, by themselves,
    provide grounds for the conclusion that evolution has occurred. An examination
    of the work of those paleontologists who have been particularly concerned with
    the relationship between paleontology and evolutionary theory, for example that
    of G. G. Simpson and S. J. Gould, reveals a mindfulness of the fact that the
    record of evolution, like any other historical record, must be construed within
    a complex of particular and general preconceptions not the least of which is
    the hypothesis that evolution has occurred. ...The fossil record doesn't even
    provide any evidence in support of Darwinian theory except in the weak sense
    that the fossil record is compatible with it, just as it is compatible with
    other evolutionary theories, and revolutionary theories and special creationist
    theories and even historical theories." (Kitts, David B., "Search for the Holy
    Transformation," review of Evolution of Living Organisms, by Pierre-P. Grassé,
    Paleobiology, vol. 5, 1979, p. 353-354)





    Stasis and Sudden Appearance



    "Paleontologists have paid an enormous price for Darwin's argument. We fancy
    ourselves as the only true students of life's history, yet to preserve our
    favored account of evolution by natural selection we view our data as so bad
    that we almost never see the very process we profess to study. ...The history
    of most fossil species includes tow features particularly inconsistent with
    gradualism: 1. Stasis. Most species exhibit no directional change during
    their tenure on earth. They appear in the fossil record looking much the same
    as when they disappear; morphological change I usually limited and
    directionless. 2. Sudden appearance. In any local area, a species does not
    arise gradually by the steady transformation of its ancestors; it appears all
    at once and 'fully formed.'" (Gould, Stephen J. The Panda's Thumb, 1980, p.
    181-182)


    "Paleontologists are traditionally famous (or infamous) for reconstructing whole
    animals from the debris of death. Mostly they cheat. ...If any event in life's
    history resembles man's creation myths, it is this sudden diversification of
    marine life when multicellular organisms took over as the dominant actors in
    ecology and evolution. Baffling (and embarrassing) to Darwin, this event still
    dazzles us and stands as a major biological revolution on a par with the
    invention of self-replication and the origin of the eukaryotic cell. The animal
    phyla emerged out of the Precambrian mists with most of the attributes of their
    modern descendants." (Bengtson, Stefan, "The Solution to a Jigsaw Puzzle,"
    Nature, vol. 345 (June 28, 1990), p. 765-766)


    "Modern multicellular animals make their first uncontested appearance in the
    fossil record some 570 million years ago - and with a bang, not a protracted
    crescendo. This 'Cambrian explosion' marks the advent (at least into direct
    evidence) of virtually all major groups of modern animals - and all within the
    minuscule span, geologically speaking, of a few million years." (Gould,
    Stephen J., Wonderful Life: The Burgess Shale and the Nature of History, 1989,
    p. 23-24)


    "The fossil record had caused Darwin more grief than joy. Nothing distressed him
    more than the Cambrian explosion, the coincident appearance of almost all
    complex organic designs..." (Gould, Stephen J., The Panda's Thumb, 1980, p.
    238-239)


    "The majority of major groups appear suddenly in the rocks, with virtually no
    evidence of transition from their ancestors." (Futuyma, D., Science on Trial:
    The Case for Evolution, 1983, p. 82)


    "Most families, orders, classes, and phyla appear rather suddenly in the fossil
    record, often without anatomically intermediate forms smoothly interlinking
    evolutionarily derived descendant taxa with their presumed ancestors."
    (Eldredge, (Eldredge, Niles, Macro-Evolutionary Dynamics: Species, Niches, and
    Adaptive Peaks, 1989, p. 22)


    "In spite of these examples, it remains true, as every paleontologist knows,
    that most new species, genera, and families, and that nearly all new categories
    above the level of families, appear in the record suddenly and are not led up
    to by known, gradual, completely continuous transitional sequences." (Simpson,
    George Gaylord, The Major Features of Evolution, 1953, p. 360)


    "The gaps in the record are real, however. The absence of any record of any
    important branching is quite phenomenal. Species are usually static, or nearly
    so, for long periods, species seldom and genera never show evolution into new
    species or genera but replacement or one by another, and change is more or less
    abrupt." (Wesson, R., Beyond Natural Selection, 1991, p. 45)


    "All through the fossil record, groups - both large and small - abruptly appear
    and disappear. ...The earliest phase of rapid change usually is undiscovered,
    and must be inferred by comparison with its probable relatives." (Newell, N.
    D., Creation and Evolution: Myth or Reality, 1984, p. 10)


    "Paleontologists had long been aware of a seeming contradiction between Darwin's
    postulate of gradualism...and the actual findings of paleontology. Following
    phyletic lines through time seemed to reveal only minimal gradual changes but
    no clear evidence for any change of a species into a different genus or for the
    gradual origin of an evolutionary novelty. Anything truly novel always seemed
    to appear quite abruptly in the fossil record." (Mayr, E., Our Long Argument:
    Charles Darwin and the Genesis of Modern Evolutionary Thought, 1991, p. 138)


    "The record certainly did not reveal gradual transformations of structure in the
    course of time. On the contrary, it showed that species generally remained
    constant throughout their history and were replaced quite suddenly by
    significantly different forms. New types or classes seemed to appear fully
    formed, with no sign of an evolutionary trend by which they could have emerged
    from an earlier type." (Bowler, Evolution: The History of an Idea, 1984, p.
    187)


    "Instead of finding the gradual unfolding of life, what geologists of Darwin's
    time, and geologists of the present day actually find is a highly uneven or
    jerky record; that is, species appear in the sequence very suddenly, show
    little or no change during their existence in the record, then abruptly go out
    of the record. and it is not always clear, in fact it's rarely clear, that the
    descendants were actually better adapted than their predecessors. In other
    words, biological improvement is hard to find." (Raup, David M., "Conflicts
    Between Darwin and Paleontology," Bulletin, Field Museum of Natural History,
    vol. 50, 1979, p. 23)


    "A major problem in proving the theory (of evolution) has been the fossil
    record; the imprints of vanished species preserved in the Earth's geological
    formations. This record has never revealed traces of Darwin's hypothetical
    intermediate variants instead species appear and disappear abruptly, and this
    anomaly has fueled the creationist argument that each species was created by
    God." (Czarnecki, Mark, "The Revival of the Creationist Crusade", MacLean's,
    January 19, 1981, p. 56)


    "Eldredge and Gould, by contrast, decided to take the record at face value. On
    this view, there is little evidence of modification within species, or of forms
    intermediate between species because neither generally occurred. A species
    forms and evolves almost instantaneously (on the geological timescale) and then
    remains virtually unchanged until it disappears, yielding its habitat to a new
    species." (Smith, Peter J., "Evolution's Most Worrisome Questions," Review of
    Life Pulse by Niles Eldredge, New Scientist, 1987, p. 59)


    "The principle problem is morphological stasis. A theory is only as good as its
    predictions, and conventional neo-Darwinism, which claims to be a comprehensive
    explanation of evolutionary process, has failed to predict the widespread
    long-term morphological stasis now recognized as one of the most striking
    aspects of the fossil record." (Williamson, Peter G., "Morphological Stasis and
    Developmental Constraint: Real Problems for Neo-Darwinism," Nature, Vol. 294,
    19 November 1981, p. 214)


    "It is a simple ineluctable truth that virtually all members of a biota remain
    basically stable, with minor fluctuations, throughout their duration..."
    (Eldredge, Niles, The Pattern of Evolution, 1998, p. 157)


    "But fossil species remain unchanged throughout most of their history and the
    record fails to contain a single example of a significant transition."
    (Woodroff, D.S., Science, vol. 208, 1980, p. 716)


    "We have long known about stasis and abrupt appearance, but have chosen to fob
    it off upon an imperfect fossil record." (Gould, Stephen J., "The Paradox of
    the First Tier: An Agenda for Paleobiology," Paleobiology, 1985, p. 7)


    "Paleontologists ever since Darwin have been searching (largely in vain) for the
    sequences of insensibly graded series of fossils that would stand as examples
    of the sort of wholesale transformation of species that Darwin envisioned as
    the natural product of the evolutionary process. Few saw any reason to demur -
    though it is a startling fact that ...most species remain recognizably
    themselves, virtually unchanged throughout their occurrence in geological
    sediments of various ages." (Eldredge, Niles, "Progress in Evolution?" New
    Scientist, vol. 110, 1986, p. 55)


    "In other words, when the assumed evolutionary processes did not match the
    pattern of fossils that they were supposed to have generated, the pattern was
    judged to be 'wrong.' A circular argument arises: interpret the fossil record
    in terms of a particular theory of evolution, inspect the interpretation, and
    note that it confirms the theory. Well, it would, wouldn't it? ...As is now
    well known, most fossil species appear instantaneously in the record, persist
    for some millions of years virtually unchanged, only to disappear abruptly -
    the 'punctuated equilibrium' pattern of Eldredge and Gould." (Kemp, Tom S., "A
    Fresh Look at the Fossil Record," New Scientist, vol. 108, 1985, p. 66-67)


    "The old Darwinian view of evolution as a ladder of more and more efficient
    forms leading up to the present is not borne out by the evidence. Most changes
    are random rather than systematic modifications, until species drop out. There
    is no sign of directed order here. Trends do occur in many lines, but they are
    not the rule." (Newell, N. D., "Systematics and Evolution," 1984, p. 10)


    "Well-represented species are usually stable throughout their temporal range, or
    alter so little and in such superficial ways (usually in size alone), that an
    extrapolation of observed change into longer periods of geological time could
    not possibly yield the extensive modifications that mark general pathways of
    evolution in larger groups. Most of the time, when the evidence is best,
    nothing much happens to most species." (Gould Stephen J., "Ten Thousand Acts of
    Kindness," Natural History, 1988, p. 14)


    "Stasis, or nonchange, of most fossil species during their lengthy geological
    lifespans was tacitly acknowledged by all paleontologists, but almost never
    studied explicitly because prevailing theory treated stasis as uninteresting
    nonevidence for nonevolution. ...The overwhelming prevalence of stasis became
    an embarrassing feature of the fossil record, best left ignored as a
    manifestation of nothing (that is, nonevolution). (Gould, Stephen J.,
    "Cordelia's Dilemma," Natural History, 1993, p. 15)


    "Paleontologists just were not seeing the expected changes in their fossils as
    they pursued them up through the rock record. ...That individual kinds of
    fossils remain recognizably the same throughout the length of their occurrence
    in the fossil record had been known to paleontologists long before Darwin
    published his Origin. Darwin himself, ...prophesied that future generations of
    paleontologists would fill in these gaps by diligent search ...One hundred and
    twenty years of paleontological research later, it has become abundantly clear
    that the fossil record will not confirm this part of Darwin's predictions. Nor
    is the problem a miserably poor record. The fossil record simply shows that
    this prediction is wrong. ...The observation that species are amazingly
    conservative and static entities throughout long periods of time has all the
    qualities of the emperor's new clothes: everyone knew it but preferred to
    ignore it. Paleontologists, faced with a recalcitrant record obstinately
    refusing to yield Darwin's predicted pattern, simply looked the other way."
    (Eldredge, N. and Tattersall, I., The Myths of Human Evolution, 1982, p. 45-46)





    Large Gaps



    "We have so many gaps in the evolutionary history of life, gaps in such key
    areas as the origin of the multi-cellular organisms, the origin of the
    vertebrates, not to mention the origins of most invertebrate groups." (McGowan,
    C., In the Beginning... A Scientist Shows Why the Creationists are Wrong,
    Prometheus Books, 1984, p. 95)


    "There are all sorts of gaps: absence of gradationally intermediate
    'transitional' forms between species, but also between larger groups - between,
    say, families of carnivores, or the orders of mammals. In fact, the higher up
    the Linnaean hierarchy you look, the fewer transitional forms there seem to
    be." (Eldredge, Niles, The Monkey Business: A Scientist Looks at Creationism,
    1982, p. 65)


    "It is as though they [fossils] were just planted there, without any
    evolutionary history. Needless to say this appearance of sudden planting has
    delighted creationists. ...Both schools of thought (Punctuationists and
    Gradualists) despise so-called scientific creationists equally, and both agree
    that the major gaps are real, that they are true imperfections in the fossil
    record. The only alternative explanation of the sudden appearance of so many
    complex animal types in the Cambrian era is divine creation and (we) both
    reject this alternative." (Dawkins, Richard, The Blind Watchmaker, W.W. Norton
    & Company, New York, 1996, p. 229-230)


    "All paleontologists know that the fossil record contains precious little in the
    way of intermediate forms; transitions between major groups are
    characteristically abrupt. Gradualists usually extract themselves from this
    dilemma by invoking the extreme imperfection of the fossil record." (Gould,
    Stephen J., The Panda's Thumb, 1980, p. 189)


    "One of the most surprising negative results of paleontological research in the
    last century is that such transitional forms seem to be inordinately scarce. In
    Darwin's time this could perhaps be ascribed with some justification to the
    incompleteness of the paleontological record and to lack of knowledge, but with
    the enormous number of fossil species which have been discovered since then,
    other causes must be found for the almost complete absence of transitional
    forms." (Brouwer, A., "General Paleontology," [1959], Transl. Kaye R.H.,
    Oliver & Boyd: Edinburgh & London, 1967, p. 162-163)


    "There is no need to apologize any longer for the poverty of the fossil record.
    In some ways it has become almost unmanageably rich, and discovery is
    out-pacing integration. The fossil record nevertheless continues to be
    composed mainly of gaps." (Neville, George, T., "Fossils in Evolutionary
    Perspective," Science Progress, vol. 48 January 1960, p. 1-3)


    "The record jumps, and all the evidence shows that the record is real: the gaps
    we see reflect real events in life's history not the artifact of a poor fossil
    record...The fossil record flatly fails to substantiate this expectation of
    finely graded change." (Eldredge, N. and Tattersall, I., The Myths of Human
    Evolution Columbia University Press, 1982, p. 59, 163)


    "Gaps between families and taxa of even higher rank could not be so easily
    explained as the mere artifacts of a poor fossil record." (Eldredge, Niles,
    Macro-Evolutionary Dynamics: Species, Niches, and Adaptive Peaks, 1989, p. 22)


    "The fossil record is much less incomplete than is generally accepted." (Paul,
    C.R.C, "The Adequacy of the Fossil Record," 1982, p. 75)


    "Links are missing just where we most fervently desire them, and it is all too
    probable that many 'links' will continue to be missing." (Jepsen, L. Glenn;
    Mayr, Ernst; Simpson George Gaylord. Genetics, Paleontology, and Evolution, New
    York, Athenaeum, 1963, p. 114)


    "For over a hundred years paleontologists have recognized the large number of
    gaps in the fossil record. Creationists make it seem like gaps are a deep, dark
    secret of paleontology..." (Cracraft, in Awbrey & Thwaites, Evolutionists
    Confront Creationists", 1984)


    "In any case, no real evolutionist, whether gradualist or punctuationist, uses
    the fossil record as evidence in favour of the theory of evolution as opposed
    to special creation." (Ridley, Mark, "Who doubts evolution?" "New Scientist",
    vol. 90, 25 June 1981, p. 831)


    "The absence of fossil evidence for intermediary stages between major
    transitions in organic design, indeed our inability, even in our imagination,
    to construct functional intermediates in many cases, has been a persistent and
    nagging problem for gradualist accounts of evolution." (Gould, Stephen J.,
    'Is a new and general theory of evolution emerging?' Paleobiology, vol 6(1),
    January 1980, p. 127)


    "The curious thing is that there is a consistency about the fossil gaps; the
    fossils are missing in all the important places." (Hitching, Francis, The Neck
    of the Giraffe or Where Darwin Went Wrong, Penguin Books, 1982, p.19)


    "If life had evolved into its wondrous profusion of creatures little by little,
    Dr. Eldredge argues, then one would expect to find fossils of transitional
    creatures which were a bit like what went before them and a bit like what came
    after. But no one has yet found any evidence of such transitional creatures.
    This oddity has been attributed to gaps in the fossil record which gradualists
    expected to fill when rock strata of the proper age had been found. In the
    last decade, however, geologists have found rock layers of all divisions of the
    last 500 million years and no transitional forms were contained in them." (The
    Guardian Weekly, 26 Nov 1978, vol 119, no 22, p. 1)


    "Given that evolution, according to Darwin, was in a continual state of
    motion...it followed logically that the fossil record should be rife with
    examples of transitional forms leading from the less to more evolved.
    ...Instead of filling the gaps in the fossil record with so-called missing
    links, most paleontologists found themselves facing a situation in which there
    were only gaps in the fossil record, with no evidence of transformational
    intermediates between documented fossil species." (Schwartz, Jeffrey H., Sudden
    Origins, 1999, p. 89)


    "Despite the bright promise that paleontology provides a means of "seeing"
    evolution, it has presented some nasty difficulties for evolutionists the most
    notorious of which is the presence of "gaps" in the fossil record. Evolution
    requires intermediate forms between species and paleontology does not provide
    them. The gaps must therefore be a contingent feature of the record." (Kitts,
    David B., "Paleontology and Evolutionary Theory," Evolution, vol. 28, 1974, p.
    467)


    "A persistent problem in evolutionary biology has been the absence of
    intermediate forms in the fossil record. Long term gradual transformations of
    single lineages are rare and generally involve simple size increase or trivial
    phenotypic effects. Typically, the record consists of successive
    ancestor-descendant lineages, morphologically invariant through time and
    unconnected by intermediates." (Williamson, P.G., Palaeontological
    Documentation of Speciation in Cenozoic Molluscs from Turkana Basin, 1982, p.
    163)





    Miscellaneous



    "All of us who study the origin of life find that the more we look into it, the
    more we feel that it is too complex to have evolved anywhere. We believe as an
    article of faith that life evolved from dead matter on this planet. It is just
    that its complexity is so great, it is hard for us to imagine that it did."
    (Urey, Harold C., quoted in Christian Science Monitor, January 4, 1962, p. 4)


    "If living matter is not, then, caused by the interplay of atoms, natural forces
    and radiation, how has it come into being? I think, however, that we must go
    further than this and admit that the only acceptable explanation is creation.
    I know that this is anathema to physicists, as indeed it is to me, but we must
    not reject a theory that we do not like if the experimental evidence supports
    it." (H.J. Lipson, F.R.S. Professor of Physics, University of Manchester, UK,
    "A physicist looks at evolution" Physics Bulletin, 1980, vol 31, p. 138)


    "To the unprejudiced, the fossil record of plants is in favor of special
    creation. Can you imagine how an orchid, a duck weed, and a palm have come
    from the same ancestry, and have we any evidence for this assumption? The
    evolutionist must be prepared with an answer, but I think that most would break
    down before an inquisition." (E.J.H. Corner "Evolution" in A.M. MacLeod and
    L.S. Cobley, eds., Evolution in Contemporary Botanical Thought, Chicago, IL:
    Quadrangle Books, 1961, at 95, 97 from Bird, I, p. 234)


    "The more one studies paleontology, the more certain one becomes that evolution
    is based on faith alone; exactly the same sort of faith which it is necessary
    to have when one encounters the great mysteries of religion." (More, Louis T.,
    "The Dogma of Evolution," Princeton University Press: Princeton NJ, 1925,
    Second Printing, p.160)


    "At the present stage of geological research, we have to admit that there is
    nothing in the geological records that runs contrary to the view of
    conservative creationists, that God created each species separately, presumably
    from the dust of the earth." (Dr. Edmund J. Ambrose, The Nature and Origin of
    the Biological World, John Wiley & Sons, 1982, p. 164)


    "One of its (evolutions) weak points is that it does not have any recognizable
    way in which conscious life could have emerged." (Sir John Eccles, "A Divine
    Design: Some Questions on Origins" in Margenau and Varghese (eds.), Cosmos,
    Bios, Theos, p. 203)


    "I am convinced, moreover, that Darwinism, in whatever form, is not in fact a
    scientific theory, but a pseudo-metaphysical hypothesis decked out in
    scientific garb. In reality the theory derives its support not from empirical
    data or logical deductions of a scientific kind but from the circumstance that
    it happens to be the only doctrine of biological origins that can be conceived
    with the constricted worldview to which a majority of scientists no doubt
    subscribe." (Wolfgang, Smith, "The Universe is Ultimately to be Explained in
    Terms of a Metacosmic Reality" in Margenau and Varghese (eds.), Cosmos, Bios,
    Theos, p. 113)

    ResponderEliminar
  2. Caro Jónatas,

    Preferia que os comentários neste blog fossem mais focados. Uma lista tão longa não permite dedicar a atenção necessária a cada um, e o método de comentário por copy-paste é mais próximo do spam que do diálogo produtivo.

    Seja como for refiro-o aqui para começar:

    http://www.talkorigins.org/faqs/quotes/mine/part1-1.html

    ResponderEliminar
  3. Ludwing, e se a mutação não for fatal e ninguem morra antes de gerar descendentes como é em muitos casos como fica essa sua declaração?

    "Mas isto é muito diferente do problema de eliminar mutações novas. Quando surge uma mutação deletéria num indivíduo basta que esse indivíduo morra sem descendentes para que a mutação seja eliminada da população. É surpreendente que Sanford tenha confundido o custo de eliminar uma mutação nova com o custo de substituir um gene presente em toda a população."

    ResponderEliminar

Se quiser filtrar algum ou alguns comentadores consulte este post.