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To: Thatcherite
why do you keep telling lies about transitional fossils

No lies from me. Darwin dedicated a whole chapter of "On the Origin of Species" to what he called "a crowd of difficulties". For example, "Can we believe that natural selection could produce...an organ so wonderful as the eye". How could organisms that need it survive without it while it was evolving over thousands or millions of years? Most complex organs and organisms must have all of the parts functioning together at once from the beginning. Any gradual acquiring of them would be fatal to their functioning. Further, "can instincts be acquired and modified through natural selection?" Darwin admits the difficulties with evolution that "some of them are so serious that to this day I can hardly reflect on them without being in some degree staggered". Darwin admitted, “Why then is not every geological formation and every stratum full of such intermediate links? Geology assuredly does not reveal any such finely graduated organic chain, and this, perhaps, is the most obvious and gravest objection which can be urged against my theory”. Darwin hoped that enough of these “missing links” would eventually be found to substantiate what he called the “theory of evolution”. Gould says, “Darwin’s argument still persists as the favored escape of most paleontologists from the embarrassment of a record that seems to show so little of evolution directly.” Dawkins adds, “Some very important gaps really are due to imperfections in the fossil record. Very big gaps, too.” Gould admits, “All paleontologists know that the fossil record contains precious little in the way of intermediate forms; transitions between major groups are characteristically abrupt.” We all know this is a waste of time posting these apparent contradictions because readers have made up their minds even though this theory on the origin of species has been decimated.
636 posted on 12/06/2005 11:10:21 AM PST by dotnetfellow
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To: dotnetfellow
No lies from me.

Followed by an avalanche of duplicity. Quote-mining (extracting out-of-context quotes to indicate something which was not what the author intended) is lying, pure and simple. You, Sir, are a liar.

641 posted on 12/06/2005 11:13:16 AM PST by Thatcherite (F--ked in the afterlife, bullying feminized androgenous automaton euro-weenie blackguard)
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To: dotnetfellow
You keep yammering about Darwin's rhetorical questions which he always answered fully and convincingly. It has been pointed out to you before what you are doing. I also gave you a link full of transitional fossils mostly unknown in Darwin's day. You seem to be pretending to be unable to see it. That doesn't look very good either.

Darwin was not afraid to face every imaginable problem of his theory. He was neither a liar nor a coward and he knew he had something real and important.

Your presentation could not be in greater contrast to his. You keep sounding the same few egregiously un-factual talking points and pretending not to see or hear the chorus of objections in which people point out one thing after another after another you have wrong. It's hard to believe you don't see. Start acknowledging some of this stuff and dealing with it.

642 posted on 12/06/2005 11:19:06 AM PST by VadeRetro (Liberalism is a cancer on society. Creationism is a cancer on conservatism.)
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To: dotnetfellow
Gould admits, “All paleontologists know that the fossil record contains precious little in the way of intermediate forms; transitions between major groups are characteristically abrupt.”

Yes, he does, but why don't we give the entire context of that quote within his argument concerning gradualism and discontinuous change:


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—if only one step in a thousand survives as a fossil, geology will not record continuous change. Although I reject this argument (for reasons discussed in ["The Episodic Nature of Evolutionary Change"]), let us grant the traditional escape and ask a different question. Even though we have no direct evidence for smooth transitions, can we invent a reasonable sequence of intermediate forms—that is, viable, functioning organisms—between ancestors and descendants in major structural transitions? Of what possible use are the imperfect incipient stages of useful structures? What good is half a jaw or half a wing? The concept of preadaptation provides the conventional answer by permitting us to argue that incipient stages performed different functions. The half jaw worked perfectly well as a series of gill-supporting bones; the half wing may have trapped prey or controlled body temperature. I regard preadaptation as an important, even an indispensable, concept. But a plausible story is not necessarily true. I do not doubt that preadaptation can save gradualism in some cases, but does it permit us to invent a tale of continuity in most or all cases? I submit, although it may only reflect my lack of imagination, that the answer is no, and I invoke two recently supported cases of discontinuous change in my defense.

On the isolated island of Mauritius, former home of the dodo, two genera of boid snakes (a large group that includes pythons and boa constrictors) share a feature present in no other terrestrial vertebrate: the maxillary bone of the upperjaw is split into front and rear halves, connected by a movable joint. In 1970, my friend Tom Frazzetta published a paper entitled "From Hopeful Monsters to Bolyerine Snakes?" He considered every preadaptive possibility he could imagine and rejected them in favor of discontinuous transition. How can a jawbone be half broken? Many rodents have check pouches for storing food. These internal pouches connect to the pharynx and may have evolved gradually under selective pressure for holding more and more food in the mouth. But the Geomyidae (pocket gophers) and Heteromyidae (kangaroo rats and pocket mice) have invaginated their cheeks to form external fur-lined pouches with no connection to the mouth or pharynx. What good is an incipient groove or furrow on the outside? Did such hypothetical ancestors run about three-legged while holding a few scraps of food in an imperfect crease with their fourth leg? Charles A. Long has recently considered a suite of preadaptive possibilities (external grooves in burrowing animals to transport Soil, for example) and rejected them all in favor of discontinuous transition. These tales, in the "just-so story" tradition of evolutionary natural history, do not prove anything. But the weight of these, and many similar cases, wore down my faith in gradualism long ago. More inventive minds may yet save it, but concepts salvaged only by facile speculation do not appeal much to me.

If we must accept many cases of discontinuous transition in macroevolution, does Darwinism collapse to survive only as a theory of minor adaptive change within species? The essence of Darwinism lies in a single phrase: natural selection is the major creative force of evolutionary change. No one denies that natural selection will play a negative role in eliminating the unfit. Darwinian theories require that it create the fit as well. Selection must do this by building adaptations in a series of steps, preserving at each stage the advantageous part in a random spectrum of genetic variability. Selection must superintend the process of creation, not just toss out the misfits after some other force suddenly produces a new species, fully formed in pristine perfection.

We can well imagine such a non-Darwinian theory of discontinuous change—profound and abrupt genetic alteration luckily (now and then) making a new species all at once. Hugo de Vries, the famous Dutch botanist, supported such a theory early in this century. But these notions seem to present insuperable difficulties. With whom shall Athena born from Zeus's brow mate? All her relatives are members of another species. What is the chance, of producing Athena in the first place, rather than a deformed monster? Major disruptions of entire genetic systems do not produce favored—or even viable—creatures.

But all theories of discontinuous change are not anti-Darwinian, as Huxley pointed out nearly 120 years ago. Suppose that a discontinuous change in adult form arises from a small genetic alteration. Problems of discordance with other members of the species do not arise, and the large, favorable variant can spread through a population in Darwinian fashion. Suppose also that this large change does not produce a perfected form all at once, but rather serves as a "key" adaptation to shift its possessor toward a new mode of life. Continued success in this new mode may require a large set of collateral alterations, morphological and behavioral; these may arise by a more traditional, gradual route once the key adaptation forces a profound shift in selective pressures.

Defenders of the modern synthesis have cast Goldschmidt as Goldstein by linking his catchy phrase—hopeful monster—to non-Darwinian notions of immediate perfection by profound genetic change. But this is not entirely what Goldschmidt maintained. In fact, one of his mechanisms for discontinuity in adult forms relied upon a notion of small underlying genetic change. Goldschmidt was a student of embryonic development. He spent most of his early career studying geographic variation in the gypsy moth, Lymantria dispar. He found that large differences in the color patterns of caterpillars resulted from small changes in the timing of development: the effects of a slight delay or enhancement of pigmentation early in growth increased through ontogeny and led to profound differences among fully grown caterpillars.

Goldschmidt identified the genes responsible for these small changes in timing, and demonstrated that large final differences reflected the action of one or a few "rate genes" acting early in growth. He codified the notion of a rate gene in 1918 and wrote twenty years later: The mutant gene produces its effect . . . by changing the rates of partial processes of development. These might be rates of growth or differentiation, rates of production of stuffs necessary for differentiation, rates of reactions leading to definite physical or chemical situations at definite times of development, rates of those processes which are responsible for segregating the embryonic potencies at definite times.

In his infamous book of 1940, Goldschmidt specifically invokes rate genes as a potential maker of hopeful monsters: "This basis is furnished by the existence of mutants producing monstrosities of the required type and the knowledge of embryonic determination, which permits a small rate change in early embryonic processes to produce a large effect embodying considerable parts of the organism." In my own, strongly biased opinion, the problem of reconciling evident discontinuity in macroevolution with Darwinism is largely solved by the observation that small changes early in embryology accumulate through growth to yield profound differences among adults. Prolong the high prenatal rate of brain growth into early childhood and a monkey's brain moves toward human size. Delay the onset of metamorphosis and the axolotl of Lake Xochimilco reproduces as a tadpole with gills and never transforms into a salamander. (See my book Ontogeny and Phylogeny [Harvard University Press, 1977] for a compendium of examples, and pardon me for the unabashed plug.) As Long argues for the external cheek pouch: "A genetically controlled developmental inversion of the cheek pouch may have occurred, recurred, and persisted in some populations. Such a morphological change would have been drastic in effect, turning the pockets 'wrong side out' (furry side in), but nevertheless it would be a rather simple embryonic change." Indeed, if we do not invoke discontinuous change by small alteration in rates of development, I do not see how most major evolutionary transitions can be accomplished at all. Few systems are more resistant to basic change than the strongly differentiated, highly specified, complex adults of "higher" animal groups. How could we ever convert an adult rhinoceros or a mosquito into something fundamentally different. Yet transitions between major groups have occurred in the history of life.

D'Arcy Wentworth Thompson, classical scholar, Victorian prose stylist, and glorious anachronism of twentieth-century biology, dealt with this dilemma in his classic treatise On Growth and Form.

An algebraic curve has its fundamental formula, which defines the family to which it belongs. . . . We never think of "transforming" a helicoid into an ellipsoid, or a circle into a frequency curve. So it is with the forms of animals. We cannot transform an invertebrate into a vertebrate, nor a coelenterate into a worm, by any simple and legitimate deformation. . . . Nature proceeds from one type to another. . . . To seek for steppingstones across the gaps between is to seek in vain, forever.

D'Arcy Thompson's solution was the same as Goldschmidt's: the transition may occur in simpler and more similar embryos of these highly divergent adults. No one would think of transforming a starfish into a mouse, but the embryos of some echinoderms and protovertebrates are nearly identical.

1984 will mark the 125th anniversary of Darwin's Origin, the first major excuse for a celebration since the centenary of 1959. I hope that our "new speaking" these few years hence will be neither dogma nor vacuous nonsense. If our entrenched, a priori preferences for gradualism begin to fade by then, we may finally be able to welcome the plurality of results that nature's complexity provides.

647 posted on 12/06/2005 11:28:24 AM PST by RogueIsland
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To: dotnetfellow; Thatcherite

Your complaints in your post are taken out of context. Darwin wrote in a manner where he posed objections to his ideas, then refuted them. You've either never read Darwin and aren't aware you're doing this, or you have read Darwin and are deliberately misreprenting his statements.

That would make you a liar.

However, if you simply haven't read Darwin, Patrick Henry has the refutation to your posted objections in one of the links on his home page. It's pretty short if you're really interested.


648 posted on 12/06/2005 11:28:43 AM PST by <1/1,000,000th%
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