Café,

Jeg er i øjeblikket i gang med Helena Cronins "The Ant and the Peacock", en historisk undersøgelse af diskussionerne omkring altruisme og seksuel udvælgelse - deraf titlen på bogen; myren ofrer altruistisk sin egen mulighed for reproduktion for tuens bedste, og påfuglehannens hale menes at være resultatet af påfuglehunnernes udvælgelse af hanner med de længste haler som deres partnere. Bogen er helt igennem pro-darwinistisk, og flere af afsnittene lader til at være skrevet med Dawkins som uofficiel medforfatter. Jeg blev derfor desto mere glædeligt overrasket over de steder, hvor Cronin åbent beskriver de `tvivlsomme' metoder, som Darwin og hans venner brugte for at udbrede hans teori.

F.eks. argumenterede tidlige darwinister ofte, at siden en eller anden biologisk struktur lod til at være dårligt designet, måtte den - alene af den grund - være fremkommet ved darwinistisk udvikling:

"We have seen that for early Darwinians there were considerably attractions in emphasising the apparent imperfections of adaptations, as evidence against conscious design and for the makeshift workings of natural selection. Such an emphasis might seem to sit oddly with a failure to appreciate costs. But Darwin and his conteporaries were more preoccupied with how unadaptive such characteristics were than with how natural selection, nevertheless, managed to balance the books." (Cronin H., 1994, "The Ant and the Peacock: Altruism and Sexual Selection from Darwin to Today", Cambridge University Press: Cambridge UK, p. 67)


Darwinisterne lagde med andre ord grunden til deres teori på en helt igennem negativ kritik af den kristne opfattelse af design, hvilket ikke blot er videnskabeligt utilstrækkeligt, men også fik adskillige til at konkludere, at darwinismen havde modbevist kristendommen.

Et sådant eksempel findes hos Darwin selv, i hans diskussion af hvordan rheaen og den sorte kostær lægger deres æg:

"Take Darwin's discussion of the apparently erratic egg-laying habits of American `ostrices' (rheas) and cowbirds (Molothrus bonariensis) (Darwin 1859, p. 218; Peckham 1959, pp. 395-6). He is trying to show a gradation in paratisism from the rheas at one end, through to the cowbirds, right up to the well-honed parasitic instincts of the European cuckoo (Peckham 1959, pp. 390-6). This is standard Darwinian procedure; such gradations provide models for how natural selection could have acted. But it is the `imperfection' displayed among this gradation that most interests Darwin, for this suggests that deliberate design has not been at work. The cowbirds' habits are `far from perfect' he says (Peckham 1959, p. 395). They lay their eggs in foster nests in such large numbers that most must be lost; they waste eggs by dropping them on the bare ground; and they sometimes start to build very inadequate nests, which they don't complete or use. Such imperfection, Darwin says delightedly, is enough to turn even a creationist into an evolutionist: `Mr Hudson is a strong disbeliever in evolution, but he appears to have been so much struck by the imperfect instincts of the Molothrus bonariensis that he quotes my words, and asks, "Must we consider these habits, not as specially endowed or created instincts, but as small consequences of one general law, namely, transition?"' (Peckham 1959, p. 396). Rather than trying to show how natural selection compensates for the damages, Darwin triumphantly writes them off as imperfection unworthy of a designer. The rhea's behaviour is equally untidy and irregular. Several of females lay their eggs in a single nest - an adaptation, Darwin says, to cope with laying a large number of eggs and at two to three day intervals between each, which would make incubation and care of young in a single nest difficult. `This instinct, however, ... as in the case of the Molothrus bonariensis, has not yet been perfected; for a surprising number of eggs lie strewed over the plains, so that in one day's hunting I picked up no less than twenty lost and wasted eggs' (Peckham, 1959, p. 369; my emphasis). Again, he is more interested in evidence of imperfection than in explaining how natural selection could allow the rhea to develop such profligate reproducing habits." (Cronin, 1994, p. 68, fremhævelser og udeladelser er Cronins)


Men nu viser det sig, at denne opførsel, i stedet for at være dårligt design, faktisk er en sindrig gruppe af forskellige taktikker, der alt i alt maksimerer antallet af æg, der overlever:

"Darwinians have recently taken another look at the ostrich (this time the real African ostrich, Struthio camelus, which behaves in the same way) (Bertram 1979, 1979a). The apparent cavalier habits of egg-laying are no longer seen as a single behavioural adaptation imperfectly executed, but as selection for varied behaviour. There is a range of ways in which to care for eggs; both hatching eggs (one's own as well as those of others) and not hatching them have costs and benefits. The eggs of others can be a buffer against predation of one's own, for example; a female without a mate to help her care for her eggs might do best by farming incubations to a mated female in spite of the risk that the foster mother will eventually discard the eggs in favour of her own; the costs of building a nest might outweigh the disadvantage of having others incubate the eggs. The result is a mixed fate of the eggs - some hatch, some perish." (Cronin, 1994, p. 69)


Så hvis en tidligere opfattelse af opførslen som værende uhensigtgmæssig ledte til konklusionen, at den havde udviklet sig, måtte en revideret opfattelse af opførslen som værende gavnlig vel lede til konklusionen, at den var blevet skabt? Næ, darwinister ser nu det gavnlige i opførslen som støttende, at den er blevet formet ved udvælgelse for varieret opførsel:

"When classical Darwinism looked at a mix of hatched and spoiled eggs it sees above all an imperfect instinct that points to absence of conscious design. For modern Darwinism, the same mix is the result of selection for mixed tactics." (Cronin, 1994, p. 69)


Dette er et eksempel på den darwinistiske dobbelttænkning (se signatur): Skabelse forudsætter godt design, og kan derfor modbevises af eksempler på dårligt design, der på samme tid understøtter darwinismen - undtagen i de tilfælde, hvor vi finder godt design, hvilket så også støtter darwinismen.

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Guds fred,
Andreas

"Dobbelttænkning betyder evnen til samtidig at have to modstridende meninger og tro på dem begge. Det intellektuelle partimedlem ved, i hvilken retning hans erindringer bør ændres; han ved derfor, at han fordrejer virkeligheden, men ved hjælp af dobbelttænkning overbeviser han sig selv om, at virkeligheden ikke er blevet forvansket. Processen må være bevidst, for ellers kunne den ikke udføres med tilstrækkelig præcision, men den må samtidig være ubevidst, for ellers ville den medføre en fornemmelse af falskhed og dermed skyldfølelse." (Orwell G., 1949, "1984", Gyldendals Tranebøger, pp. 169-70)
Hjemmeside: http://www.geocities.com/evolutionsteori/
Diskussion: http://groups.yahoo.com/group/Skabelse_Evolution/
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