Lets start with the first argument often put forth by creationists...

WHY DO SCIENTISTS DEBATE EVOLUTION AMONG THEMSELVES?

A question often raised by creationists is "why, if the evidence for evolution is so sound, do scientists continue to debate it among themselves"? The answer is that scientists do not debate whether or not evolution occurs, because the strength of this evidence is overwhelming. Debate generally centers, instead, on topics such as those listed below. mechanisms that have driven evolution
the time course of various evolutionary events
specific ancestor for an organism or group of organisms

a. Mechanisms that have driven evolution

As one example of the kind of debate on evolution that occurs among scientists, examine briefly possible mechanisms that may operate to drive evolution. Darwin proposed that the driving mechanism for evolutionary change was natural selection. Basically, Darwin observed that variations occur within a species and that more offspring are produced than survive to reproduce. He proposed that individuals bearing variations that prove to be beneficial (adaptive) to a particular environment are the most likely to survive to produce offspring, thereby passing along those traits to the next generation. As the process continues over time, the population gradually changes as heritable environmentally selected adaptations are passed on to successive generations.

Since the time of Darwin, however, evidence has emerged to suggest that natural selection may not be the only mechanism leading to change. For example, chance plays a role (the Sewell-Wright phenomenon of "genetic drift").

b. The time course of various evolutionary events

It has been proposed that change may not always be gradual as proposed by Darwin; instead, evolution may occur in "fits and starts" (Eldredge and Gould’s hypothesis of "punctuated equilibrium).

c. Specific ancestor for an organism or group of organisms

An example of a more recent and widely publicized debate centers on the origin of birds. Ann C. Burke and Alan Feduccia, faculty members in the Department of Biology at UNC-Chapel Hill, recently provided evidence that the widely held hypothesis that birds arose from dinosaurs may be false [5]. Both dinosaurs and birds have only 3 digits (fingers) in the ‘hand,’ and dinosaurs possess digits I, II, and III. Burke and Feduccia found, from examination of embryos of birds, that birds possess digits II, III, and IV, suggesting that birds cannot have arisen from the dinosaurs.
Debate among scientists is useful, even critical, but has created problems of credibility outside the scientific community. For example, coverage in The Charlotte Observer of the discovery by Burke and Feduccia bore the headline, "Thumbs down on dinosaur-bird link? UNC embryo study suggests evolution theory is ‘definitely in trouble.’ [6]" Feduccia confirmed, of course, that it is not the theory of evolution that is in trouble, but only the origin of birds from dinosaurs. Feduccia stated that "birds are derived from archosauran reptiles. [7]"

How big a role does chance play in directing evolution? How common is discontinuous evolution? Are birds derived from dinosaurs or from other reptiles? These are the kinds of questions that scientists debate scientifically, not whether or not evolution occurred.

The implication of the problem scientific debate causes outside the scientific community is well stated by Stephen J. Gould:


Most of all I am saddened by a trend I am just beginning to discern among my colleagues. I sense that some now wish to mute the healthy debate about theory that has brought new life to evolutionary biology. It provides grist for creationist mills, they say, even if only by distortion. Perhaps we should lay low and rally around the flag of strict Darwinism, at least for the moment -- a kind of old-time religion on our part. But we should borrow another metaphor and recognize that we too have to tread a straight and narrow path, surrounded by roads to peridition. For if we ever begin to suppress our search to understand nature, to quench our own intellectual excitement in a misguided effort to present a united front where it does not and should not exist, then we are truly lost [8].

I will post more aftre I hear some sort of preordained arguments from teh creationists...

also a note we have had this argument before....