If we choose a weak and foolish speculation as a primary textbook illustration (falsely assuming that the tale possesses a weight of history and a sanction of evidence), then we are in for trouble - as critics properly nail the particular weakness, and then assume that the whole theory must be in danger if supporters choose such a fatuous case as a primary illustration.
Unfortunately, all life on earth - the only life we know - represents, for all its current variety, the results of a single experiment , for every earthly species evolved from the common ancestry of a single origin. We desperately need a repetition of the experiment (several would be better, but let's not be greedy!) in order to make a judgement. Mars represents our first real hope for a second experiment - the sine qua non - for any proper answer for the question of questions.
Taxonomy (the science of classification) is often undervalued as a glorified form of filing-with each species in its folder, like a stamp in its prescribed place in an album; but taxonomy is a fundamental and dynamic science, dedicated to exploring the causes of relationships and similarities among organisms. Classifications are theories about the basis of natural order, not dull catalogues compiled only to avoid chaos.
The history of life is more adequately represented by a picture of 'punctuated equilibria' than by the notion of phyletic gradualism. The history of evolution is not one of stately unfolding, but a story of homeostatic equilibria, disturbed only 'rarely' (i.e. rather often in the fullness of time) by rapid and episodic events of speciation.
Our creationist detractors charge that evolution is an unproved and unprovable charade-a secular religion masquerading as science. They claim, above all, that evolution generates no predictions, never exposes itself to test, and therefore stands as dogma rather than disprovable science. This claim is nonsense. We make and test risky predictions all the time; our success is not dogma, but a highly probable indication of evolution's basic truth.
The journalistic tradition so exalts novelty and flashy discovery, as reputable and newsworthy, that standard accounts for the public not only miss the usual activity of science but also, and more unfortunately, convey a false impression about what drives research.
Results rarely specify their causes unambiguously. If we have no direct evidence of fossils or human chronicles, if we are forced to infer a process only from its modern results, then we are usually stymied or reduced to speculation about probabilities. For many roads lead to almost any Rome.
Still, our creationist incubi, who would never let facts spoil a favorite argument, refuse to yield, and continue to assert the absence of all transitional forms by ignoring those that have been found, and continuing to taunt us with admittedly frequent examples of absence.
There is no gene "for" such unambiguous bits of morphology as your left kneecap or your fingernail. [...] Hundreds of genes contribute to the building of most body parts and their action is channeled through a kaleidoscopic series of environmental influences: embryonic and postnatal, internal and external. Parts are not translated genes, and selection doesn't even work directly on parts.
I contend that the continued racial classification of Homo sapiens represents an outmoded approach to the general problem of differentiation within a species. In other words, I reject a racial classification of humans for the same reasons that I prefer not to divide into subspecies the prodigiously variable West Indian land snails that form the subject of my own research.
Darwinian evolution may be the most truthful and powerful idea ever generated by Western Science, but if we continue to illustrate our conviction with an indefensible, unsupported, entirely speculative, and basically rather silly story, then we are clothing a thing of beauty in rags - and we should be ashamed, "for the apparel oft proclaims the man.
When scientists need to explain difficult points of theory, illustration by hypothetical example - rather than by total abstraction - works well (perhaps indispensably) as a rhetorical device. Such cases do not function as speculations in the pejorative sense - as silly stories that provide insight into complex mechanisms - but rather as idealized illustrations to exemplify a difficult point of theory. (Other fields, like philosophy and the law, use such conjectural cases as a standard device.
When we seek a textbook case for the proper operation of science, the correction of certain error offers far more promise than the establishment of probable truth. Confirmed hunches, of course, are more upbeat than discredited hypotheses. Since the worst traditions of "popular" writing falsely equate instruction with sweetness and light, our promotional literature abounds with insipid tales in the heroic mode, although tough stories of disappointment and loss give deeper insight into a methodology that the celebrated philosopher Karl Popper once labeled as "conjecture and refutation.
[G]enes make enzymes, and enzymes control the rates of chemical processes. Genes do not make "novelty seeking" or any other complex and overt behavior. Predisposition via a long chain of complex chemical reactions, mediated through a more complex series of life's circumstances, does not equal identification or even causation.
My own field of paleontology has strongly challenged the Darwinian premise that life's major transformations can be explained by adding up, through the immensity of geological time, the successive tiny changes produced generation after generation by natural selection.
Organisms [...] are directed and limited by their past. They must remain imperfect in their form and function, and to that extent unpredictable since they are not optimal machines. We cannot know their future with certainty, if only because a myriad of quirky functional shifts lie within the capacity of any feature, however well adapted to a present role.
Rifkin's assertions bear no relationship to what I have observed and practiced for 25 years ... Either I am blind or he is wrong - and I think I can show, by analyzing his slipshod scholarship and basic misunderstanding of science, that his world is an invention constructed to validate his own private hopes ... Rifkin shows no understanding of the norms and procedures of science: he displays little comprehension of what science is and how scientists work.
Skepticism's bad rap arises from the impression that, however necessary the activity, it can only be regarded as a negative removal of false claims. Not so... Proper debunking is done in the interest of an alternate model of explanation, not as a nihilistic exercise. The alternate model is rationality itself, tied to moral decency--the most powerful joint instrument for good that our planet has ever known.
Perhaps randomness is not merely an adequate description for complex causes that we cannot specify. Perhaps the world really works this way, and many events are uncaused in any conventional sense of the word. Perhaps our gut feeling that it cannot be so reflects only our hopes and prejudices, our desperate striving to make sense of a complex and confusing world, and not the ways of nature.
... many folks take them seriously because they just 'know' that evolution can never be seen in the immediate here and now. In fact, a precisely opposite situation prevails: biologists have documented a veritable glut of cases for rapid and eminently measurable evolution on timescales of years and decades.
We live in an essential and unresolvable tension between our unity with nature and our dangerous uniqueness. Systems that attempt to place and make sense of us by focusing exclusively either on the uniqueness or the unity are doomed to failure. But we must not stop asking and questing because the answers are complex and ambiguous.
Since the universe must contain millions of appropriate planets, consciousness in some form - but not with the paired eyes and limbs, and the brain built of neurons in the only example we know - may evolve frequently. But if only one origin of life in a million ever leads to consciousness, then Martian bacteria most emphatically do not imply Little Green Men.
Phony psychics like Uri Geller have had particular success in bamboozling scientists with ordinary stage magic, because only scientists are arrogant enough to think that they always observe with rigorous and objective scrutiny, and therefore could never be so fooled while ordinary mortals know perfectly well that good performers can always find a way to trick people.