I.P.:
I don't have a problem with variation, it exists - there is OVERWHELMING data that variation exists. It is typical of evolutionists "when grinding the evolutionary axe" to use examples of micro-evolution (genetic variation) to explain or defend macro-evolution(the mechanism for crossing family, class or order lines)
Crossing family, class, or order lines is a rare occurrence, an exception to the rule, and by far not the primary mechanism of 'macroevolution'. In case you haven't noticed, the aforementioned classifications stem from a tree, where branches come out of common points and then proceed to diverge, hardly ever meeting again. For example, speaking of class: I dare you to demonstrate at least one example where a mammal species over time ceased to belong to the class Mammalia. It is true that the converse has occurred: reptilians in a singular event have given rise to mammals. However, it is only true if you are willing to concede macroevolution, which is something you vehemently argue against. So which is it, professor?
Furthermore I would like to direct your attention, if that can be done, to the fact that kingdoms, phylums, classes, orders, families, genuses and species are only artificial classifications in an effort to tabulate the diversity of life. In no way, shape or form does any one of such categories present in itself some kind of an impenetrable wall that forever guards species defined by it from leaving its boundaries.
And what do you define as 'variation', anyway? Is the case of the 'wolf boys' whose faces are completely covered with thick fur a case of variation? In which event, allow yourself to imagine what happens if they give rise to in-bred families due to their specific (and to many appalling) appearance. This new sub-population would then most likely form a new 'race' (and incidentally, I direct your attention to the existence of races in the real world.) What happens when a breed is isolated all by itself on a segregated landmass such as an island, and finds no way to connect back to the other members of its species? Well, probably it would proceed to gradually splinter into sub-populations of its own, each one with a distinct and unique gene pool. Alternatively, if the segregated region is not large enough for such differentiation, the breed as a whole will undergo a gradual genetic drift; the smaller the population, the faster it drifts. Now, extrapolate that process over a million years. The minor reshufflings and minor mutations gradually accumulate to make different breeds less and less alike. When enough time passes, they are no longer able to interbreed, and thus have differentiated into distinct species. Given more time, they might even join distinct genuses, distinct families, distinct orders, and with many millions of years they may even give rise to a new class or two. Which part of this sounds forbiddingly unreasonable to you?
The distinction between 'microevolution' and 'macroevolution' is an artificial one; there is no sharp boundaries between the two. The difference is akin to considering one decade of human history versus one millennium. Obviously, a lot more change occurs over a millennium than over a decade - but one has to keep in mind that the millennium itself is composed of decades. In the same vein, the small variations between individuals of a species viewed as 'microevolution', compound with passage of time to produce ever greater differences and thereby underlie 'macroevolution'. The Darwinian/Wallacian theory of 'evolution by natural selection' is built upon three fundamental observations: 1) individuals of a given species are not identical, 2) some of this variation is heritable, 3) not all offspring survive. The crucial inference: the variations among individuals affect the probabilities that they will survive and reproduce. This is all that is necessary to deduce evolution by sheer reason. If you are going to discount evolution, you better tell us which of the three fundamental axyoms is false, or why the primary inference cited above is unreasonable (by the way, nowadays that inference is part of empirical observations, and is no longer a leap of reason but sheer fact). Otherwise, I would like you to challenge the logic through which evolution is deduced, and see how far you can get. Here goes via reductio ad absurdum:
Theorem 1: 'Macroevolution' does not exist. I.e. no new species can appear spontaneously.
[Aside: I must intercede with a little factual background (which should be common knowledge). It is observed that certain plant and animal species have existed on Earth less time than others. This means that as other species already existed, new species were appearing. Since new species cannot appear spontaneously according to Theorem 1, we have to assume that new species appear artificially over time (e.g. through strangely incremental divine creation, or alien genetic experiments spanning billions of years, or whatever else touches the fancy). Now, back to the proof…]
Lemma 1: The set of all genetic variations among all presently living individuals of any species can never acquire new members.
Proof (reductio ad absurdum):
Assume new genetic variations can appear within a species. Let a species be separated by chance into two distinct subpopulations unable to contact each other. Now, with the passage of time new genetic variations appear in the two distinct genetic pools. Because this happens independently, the chance that these new genetic variations are identical is very small. With more time, new genetic variations independently appear within the two genetic pools. Eventually, many new genetic variations have accumulated within the two distinct gene pools, and the chance that all of the new mutations between the two pools are identical is vanishingly small. Therefore, the two breeds of our species now contain distinct, and mutually exclusive genetic information. As they continue to exist independently, the genetic chasm between them grows, until one day the difference becomes too large for one breed to be able to carry children from another. Now, we have two distinct species where before was only one. But this contradicts Theorem 1 which we have set out to eventually prove! Therefore, the initial assumption of this sub-proof cannot be correct, which necessitates Lemma 1. Q.E.D.
Lemma 2: For any particular species, with time all members of the species must exhibit identical genomes.
Given Lemma 1, no new genetic features can ever appear in a gene pool of a species. However, nothing prevents features from disappearing. Genetically selective diseases, vagaries of uneven breeding and mate selection, natural accidents and, in short, environmental pressures all conspire to disturb the balance of the gene pool. With time, the random perturbations must result in certain genetic traits being restricted only to a few individuals within a population. Once that happens, more mishaps, or a massive disaster, can easily obliterate the few individuals sharing a particular genetic trait. With that, a species loses some of its genetic diversity. Hence, by pure statistical chance a species must loose little bits of its original variability with time. Since no new traits can appear due to Lemma 1, given enough time a species must loose all of its original variability, and with time, all individuals must exhibit identical genomes, identical appearances and identical physical characteristics. Q.E.D.
Lemma 3: Older species must exhibit less genetic variability.
This is easy to see given lemma 2.
Fact: Older species are observed empirically to have more genetic variability than younger species!
But how are we to reconcile fact with Lemma 3? Simple: Lemmas 3, 2, and 1 are false. As their single fundamental premise is Theorem 1, we must conclude, that in view of the facts, Theorem 1 is also false. Therefore, older species as a rule have more genetic variability, no species has ever exhibited genetically identical individuals, new features indeed appear within gene pools of species, and new species indeed emerge based on genetic variability and natural pressures - which is what we commonly refer to as 'evolution'. Case closed.
Now, I have shown that evolution is reality. The last point of contention is the source of new genetic features. Is it random mutations or ever-continuing divine tweaking? At this point, it doesn't really matter - because either way the new genetic features are referred to as 'benign mutations' - to which you, I.P., openly deny existence. Perhaps, it's time you reconsidered your stance?
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I am; therefore I think.
