Just in case I'm not alone in the difficulties I've faced attempting to following the discussion between Scott and Fred, I thought I'd respond to Fred's excellent post with what I hope will be some clarifications. Please post corrections to anything I get wrong.
The first questions has to be, "What is Haldane's Dilemma?" because I don't think it's apparent from only a reading of the dialogue between Scott and Fred.
Haldane's dilemma can be characterized through the example of man/chimp evolution. The evolutionary view is that some millions of years ago man and chimp shared a common ancestor from which both species eventually evolved, and today the difference between the chimp and man genome is around 2%. But man and chimp are both slowly reproducing species, so how could a difference of 2% occur in only 5 million years given prevailing rates of evolutionary change.
Haldane brought some mathematical rigor to this issue, characterizing it in terms of beneficial and non-beneficial allelic changes, dominant and recessive genes, rate of fixation of an gene in a population, and so forth. But one doesn't have to approach it on a mathematical level to wonder how so much change could occur in so little time, and even evolutionists must concede that biology does not as of yet have satisfactory models to explain fairly rapid species change for animals like ourselves. The fossil differences between Australopithicus afarensis and Homo habilis are enormous, and if habilis is actually a descendent of afarensis (something that can only be conjectured at this point) then we have little idea how the change from one to the other took place.
Lack of transitionals is the source of the lack of insight. This common Creationist objection to the fossil evidence has some validity. The well-documented example of horse evolution illustrates a clear and lengthy (in time) record of transition from one horse species to another, but how did the transitions between those species take place? There's no fine gradation. Is punctuated equilibrium the answer? Perhaps, but in a way this is an argument from no evidence, a charge often cast at Creationists.
So Haldane's Dilemma can in some small way be viewed as a specialized form of the question about missing transitional fossils. How did the angle of the hip joint change? What about the orientation and shape of the pelvis? How about the angle of the skull on the backbone. What about skull and brain changes? How much, when, how fast, sequentially or all at the same time? We don't know.
To evolutionists the fossil record is clear and unequivocal evidence that evolution has happened, but we must concede that we have little understanding of the actual process by which a new species with significant morphological differences evolves. To Creationists the fossil record is so clearly full of holes that it serves as very poor evidence of evolution and much better evidence of special creation. I think this skepticism is well founded, though it is scant justification for the Creationist flights of fancy that involve rejecting much of cosmology, physics, geology and biology.
Trying to imagine the detailed changes human ancestral species might have gone through on their way to evolving into us brings some helpful visualization to the more abstract details of the Haldane's Dilemma discussion, which from a Creationist standpoint merely postulates that the rate of evolutionary change is too slow for a chimp/man ancestor to have evolved into us.
If either Fred or Scott is willing, this might be a good time to summarize the current state of the Haldane's Dilemma discussion.
--Percy
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