Why do you debate about evolution?

Here's an interesting take on the subject by Colin Patterson, from his book:

Colin Patterson, Evolution, 2nd Ed. (1999)
Ch. 14 - Proof and disproof; science and politics emphases mine, [paraphrases in square brackets], [my comments in small print].
Turning now to the second or special theory of mechanism, many critics have held that natural selection, as the cause of evolution, is not scientific because the expression 'survival of the fittest' makes no predictions except 'what survives is fit' and so is tautologous.... Indeed, natural selection theory can be presented in the form of a deductive argument, for example:

All organisms must reproduce.
All organisms exhibit hereditary variations.
Hereditary variations differ in their effect on reproduction.
Therefore variations with favourable effects on reproduction will succeed, those with unfavourable effects will fail, and organisms will change.
In this sense, natural selection is not a scientific theory but a truism, something that is proven to be true, like one of Euclid's theorems... [Genetic drift & neutral drift can also protect natural selection from the possibility of falsification.]
[Patterson seems to be saying that natural selection is actually more than a tautology - it's axiomatic - proven true like Euclid's theorems!]
...But the essence of scientific method ... is to test two (or more) rival theories, like Newton's and Einstein's, and to accept the one that passes more or stricter tests until a better theory turns up. We must look at evolution theory and natural selection theory in terms of performance against the competition.
[The general theory of evolution] has only one main competitor, creation theory.... All creation theories are purely metaphysical. They make no predictions about the activities of the Creator, except that life as we know it is the result of His plan. Since we do not know the plan, no observation can be inconsistent with it. ...
In 1978 Popper wrote that the Darwinian theory of common descent 'has been well tested' (he did not say how) and 'That the theory of natural selection may be so formulated that it is far from tautological. In this case it is not only testable, but it turns out to be not strictly universally true. ... Yet in every particular case it is a challenging research programme to show how far natural selection can possibly be held responsible for the evolution of a particular organ or behavioural programme.'

Here's another interesting article that claims natural selection has been proved empirically:

Can Human Aging be Postponed? Michael R. Rose, Scientific American, Dec 1999
Aging does not occur because of some universal defect in all cell types. If some singular, unavoidable flaw caused every cell to fail eventually, no animal would escape aging. But some do. For example, asexual sea anemones kept for decades in aquariums do not show failing health. Nor does aging derive from a genetic program designed by nature to block overpopulation. Instead senescence is the by-product of a pattern of natural selection that afflicts humans and other vertebrates but not vegetative sea anemones. More specifically, aging arises in sexually reproducing species because the force of natural selection declines after the start of adulthood.
This concept follows logically from general evolutionary theory. Heritable traits persist and become prevalent in a population - they are selected, in evolutionary terms - if those properties help their bearers to survive into reproductive age and produce offspring. The most useful traits result in the most offspring and hence in the greatest perpetuation of the genes controlling those properties. Meanwhile traits that diminish survival in youth become uncommon - are selected against - because their possessors often die before reproducing.
In contrast to deleterious genes that act early, those that sap vitality in later years would be expected to accumulate readily in a population, because parents with those genes will pass them to the next generation before their bad effects interfere with reproduction. (The later the genes lead to disability, the more they will spread, because the possessors will be able to reproduce longer.) Aging, then, creeps into populations because natural selection, the watchdog that so strongly protects traits ensuring hardiness during youth, itself becomes increasingly feeble with adult age.
...
In the 1940s and 1950s, J. B. S. Haldane and Nobelist Peter B. Medawar, both at University College London, were the first to introduce this evolutionary explanation of aging. W. D. Hamilton of Imperial College and Brian Charlesworth of the University of Sussex then made the thesis mathematically rigorous in the 1960s and 1970s.
In their most important result, Hamilton and Charlesworth established that for organisms that do not reproduce by splitting in two, the force of natural selection on survival falls with adult age and then disappears entirely late in life. Because natural selection is the source of all adaptation, and thus of health, the hardiness of older organisms declines as natural selection fades out. Eventually, with the continued absence of natural selection at later ages, survival may be so imperiled that optimal conditions and medical care may be unable to keep the older individual alive.
Since the 1970s the original mathematical proofs have been confirmed experimentally many times, most often by manipulations that deliberately prolong the period of intense natural selection in laboratory animals. Investigators extend this period by delaying the age at which reproduction begins; they discard all fertilized eggs produced by young animals and use only those produced late in life. As a result, only individuals who are robust enough to reproduce at an advanced age will pass their genes to the next generation.
If the declining strength of natural selection after the start of reproduction really does explain the evolution of aging, then progressively retarding this drop for a number of generations in a test population should lead to the evolution of significantly postponed aging in that lineage. This prediction has been shown to be true in fruit flies of the genus Drosophila that have had reproduction delayed across 10 or more generations. As a result of these experiments, scientists now have stocks that live two to three times longer than normal and are healthy longer as well.
The flies that display postponed aging are surprisingly perky. They do not merely sustain normal biological functions for longer periods; they display superior capabilities at all adult ages. In youth and later, they are better able to resist such normally lethal stresses as acute dessication and starvation. They also show more athletic prowess than their like-aged counterparts do, being able to walk and fly for longer periods.

Indeed, natural selection theory can be presented in the form of a deductive argument . . .

You know, everything in mathematics is a deductive argument and nobody ever seems to complain about the tautological nature of that. In fact, you still wind up with new-looking statements that amount to new information at the time you deduce them, even if they're ultimately based upon a few already-familiar assumptions, postulates, and prior conclusions from same.

... everything in mathematics is a deductive argument and nobody ever seems to complain about the tautological nature of that.

To God, wouldn't everything be a tautology? Who complains about that?

It's the need to be right. Both sides of the "crevo" debate have a hard time admitting that they are not "holding all the cards" and that they cannot explain everything, therefore they take every oppourtunity to condescend to the "foolishness" of the other side of the debate. Most have a REAL axe to grind.

Damn straight, ya hairless ape.

Only that you can't survive if you aren't sufficiently fit to do so. I suppose one could speculate that in a simple prey-preditor relationship, as the weakest of the prey are consumed, the herd of prey animals are constantly being strengthened because the weak among them are being culled. And that would put pressure on the preditors to weed out the slowpokes among them too. Thus a kind of "arms race" would seem to be inevitable. That doesn't mean that lions will evolve into "Terminator" killers, however. Just that they'll stay strong enough to feed themselves on the prey animals.

More to the point, in a predator-prey relation, if the predator evolves skills so good that they allow it to wipe out the prey population, then the predator is screwed; it will go extinct from the lack of food after the gluttony. Similarly, if the prey evolve a 100% effective defense, the predators die out (again, from starvation, but with no gluttony preceding it) and there is nothing then to check the virtually exponential population growth rate of the prey population, until finally it exhausts ITS food supply, and starves itself out of existence.

Hence, when we observe predator-prey relationships, we find that they are fairly well balanced (though there might be cyclical variations in populations of predator and prey); this is because all others were dynamically unstable, and lead to almost certain extinction of one or both the predator and the prey. The "stable" predator-prey relationships are they only ones that can be sustained on a long term basis, so it should be no surprise that these are all we see.

To assert that Evolutionary Theory predicts "perfect" adaptation is to credit it with too much. To think so, is to think that evolution says that, given time to adapt, all predators are born with Swiss army knives on their paws and Sidewinder Infrared Heat seekers in their eyes, and all prey are eventually born with Titanium skin and high-power radar.

Evolution really says that under some circumstances, being too "successful" can be just as deadly as being not successful enough. Or so it seems to me....

Evolution is about, as you put it, being successful "enough," compared to the competition, to survive and pass on the genes. Evolution does not demand that every organism that avoids extinction be the "Perfect" critter, just "well adapted." And the reason is clear; the level of survival pressure.

Absent an almost 100% mortality rate prior to passing on its genes, a critter doesn't need to be "perfectly" adapted. And as pointed out above, there are circumstances where being "too good" is as good as being dead.

Evolution does not demand that every organism that avoids extinction be the "Perfect" critter, just "well adapted."

Ah, that explains why I haven't reproduced yet. I'm way too ahead of the curve to be "well adapted."

Ah, that explains why I haven't reproduced yet. I'm way too ahead of the curve to be "well adapted."

Well, that's ONE excuse.....

Thank you all for your contributions and for taking the time to respond. VadeRetro has alluded to the tremendous complexity of analysis and understanding of the phenomena under discussion, a point with which I agree, but it also means that I probably cannot speak to each point with the level of detail it deserves.

Leaving my invisible friend out of this for the moment, in regard to the role of competition to the ability of organisms to reproduce successfully, even assuming that competition plays as large a role as is assigned to it, it might not neccessarily be beneficial. Presumably there are many cases where it might be be detrimental. There are a whole host of factors, including 'luck' that play a part in the success or failure of an individual of a species. Sometimes it is not the 'fittest' that survives, but the dammned luckiest, a characteristic that is usually not considered to be inheritable.

I have been trying to get my hands aroung the concepts of natural selection and survial of the fittest for a long time. On one hand, natural selection is consistent with the idea that all organisms in stable environments have reached a fitness at which they will remain forever. At the same time natural selection is compatible with the notion that all organisms could regress to being a single cell organism because that would be the SAFEST and optimal adaptation to every environment. Natural selection can be made to explain both the occurrence of evolutionary characteristics and the non-occurrence of evolutionary characteristics, which I mentioned previously. (I think non-occurrence of phenomena may also provide valid information to exmaine causes and effects, like the clue in the Sherlock Holmes story where the dog did NOT bark.) Natural selection can even be made to explain individual adaptations that are mutually opposed, such as camouflage coloring and warning coloring. It can be made to explain stasis, diversity and mono-speciation. My point was that the most successful breeders populate the world, and the less successful breeders die out - regardless of their respective characteristics. This is a truism.

To give myself some cover here, it was C.H. Waddinton, in 1960 who called the the concept of natural selection a tautology, which he nevertheless regarded as an ACHIEVMENT, not a discreditation!

Darwin's major contribution was, of course, the suggestion that evolution can be explained by the natural selection of random variations. Naural selection, which was at first considered as though it were a hypothesis that was in need of experimental or observational confirmation, turns out on closer inspection to be a tautology, a statement of an inevitable although previosly unrecognised relation. It states that the fittest individuals in a population (defined as those which leave most offspring) will leave most offspring. Once the statement is made, its truth is apparent. This fact in no way reduces the magnitude of Darwin's achievement; only after it was clearly formulated, could biologists realise the enormous power of the principle as a weapon of explantion."

Waddinton, C.H 1960. Evolutionary Adaptation in Tax 1: 381-402

jennyp, the validity of Patterson's comments about competing theories, aside from the issue of the self-contained coherence of any theory itself, depend upon the validity of his presuppositions of naturalism (or scientism; that nothing exists of any kind that cannot be known or discovered by the five senses), and the existence of the myriad forms and diversity of life requires an explanation, and following from those, that Darwinism is all we've got, therefore it must be true. It is at least logically possible, though, that the aforesaid involves the fallacy of false exclusion. I am still looking at the piece on experimental observation of natural selection. Assuming that I understand it, and assuming that the observations regarding aging and reproduction are true, I still don't see how the hardiness of older organisms declining as natural selection fades out, and eventually, with the continued absence of natural selection at later ages, survival becoming so imperiled that optimal conditions and medical care may be unable to keep the older individual alive, is an IMPROVEMENT.

PatrickHenry and longshadow have defined some of the limitations or boundaries of the concept natural selection, which I appreciate as being helpful to understanding the the complex and intertwined set of issues involved. Some have claimed that I have made too much of natural selection. But I should make clear that I believe that natural selection, to whatever extent it exists, is an EFFECT, not a cause of anything. It has no power of it's own, just like history is not a power or a force of its own. It is an effect, the cause of which is probably unknown to us. There are natural limits on the amount of variation that can be induced in species. There are natural barriers to genetic variation. Darwin at first hypothethized that bears could gradually be transformed into whale-like animals, which although he later withdrew the example, is still basically the central claim of evolution. Bears can become whales. Microbes can become elephants, by means of random mutation and natural selection. Whatever the creative power of random mutation, I don't believe natural selection is possessed of the powers generally assigned to it.

Cordially,

Regarding luck: if you're lucky, you pass on the genes you have to pass on. If you're unlucky, you don't. For all that, the good genes tend to assert themselves.

On one hand, natural selection is consistent with the idea that all organisms in stable environments have reached a fitness at which they will remain forever.

That has worked for cyanobacteria, which are still around in forms very similar to those we see in the fossil record maybe three billion years ago. Some other life forms have managed not to change too much since they showed up on the scene. More often, however, things change and the organisms have to adjust or die. The earth has seen a near-global icesheet, a steamy global jungle (in the Triassic, Jurrassic, and Cretaceous), back to somewhat icy (in the Pleistocene), and the moderation of temperatures we see just now. All that and various big things dropping out of the sky here and there. All of which can mess up what had been a perfectly good adjustment.

At the same time natural selection is compatible with the notion that all organisms could regress to being a single cell organism because that would be the SAFEST and optimal adaptation to every environment.

You're back in "Elsie-mode," the construction of silly scenarios followed by the statement "Evolution says that could happen." It's often untrue, and there's no reason to think that a thing has to happen because it has some chance. Anytime I buy a Lotto ticket, I have a chance to win the jackpot. I almost never do.

Multi-cellularism comes from symbiosis, which was invented very early. (Stromatolites, etc.) It has its own advantages. The path backwards is not simple and the pressures to go that way may be lacking.

Multi-cellularism comes from symbiosis, which was invented very early. (Stromatolites, etc.)

. . . and colonialism. (Slime molds, etc.)

I have been trying to get my hands aroung the concepts of natural selection and survial of the fittest for a long time.

The concepts are really very easy to understand. It's the evidence which can get complicated.

On one hand, natural selection is consistent with the idea that all organisms in stable environments have reached a fitness at which they will remain forever.

Yes. Single-celled organisms have been around pretty much since life began. They are the most abundant form of life on earth. All us multi-cellular forms are relatively trivial in comparison. We are a minute percentage of the biosphere.

At the same time natural selection is compatible with the notion that all organisms could regress to being a single cell organism because that would be the SAFEST and optimal adaptation to every environment.

I don't understand that at all. Birds don't sit around and say: "Golly, there's a lot of hunters around; we'd be safer if we all reverted to being bacteria. Let's do it!" Nothing like that happens. If they survive and breed, they're going to stick around. If they go extinct, well, that's it. Why are you trying to make this so complicated?

On the Natural selection of Random variations being overrated as a means to advance life;

Random: Without a governing design, method, or purpose, unsystematically. As in "chose a card at random from the deck".

The chooser is not the important one in evolution. The One who originally shuffled the cards is really The important entity in the entire equation.

And this isn't just simplistic talk. If God had inserted evolution as a controlling force at the moment of the big bang, then All Creation events leading up to this very moment, are being controlled by a God's own process, set in motion at the beginning of time.

You very existence is proof of the master-evolution plan!

(Slime molds, etc.)

Isn't that what G3K accuses the Evos of using on him?

You may see the custom as strange (and what custom isn't a bit strange) but this agnostic spells it "G-d" out of respect for an ancient tradition. See, we're not such irreverent people after all!

Whoops, strike the "a" in front of God's own process. Major typo!

I thought maybe he'd been more influenced by the movie "Ghostbusters." The slime and "sliming" is only part of why I think so. With its depiction of supernatural forces giving a team of science-oriented types all that they can handle, it was probably a major cultural event in his education.

I always thought "Ghostbusters" was a documentary.

There are natural barriers to genetic variation.

What are these barriers?