Surely even a creationist should be able to see the fallacy in the above "reasoning". It's like examining one parked car and then concluding, based on its immobility, that no one could ever drive to Cleveland before their car rusted out.
To *properly* examine these things (you know, like a scientist, not like a creationist), one needs to look at the *average* rate of change for a number of species (not just point at the *slowest* changing one yet found and then pretend that it's somehow representative).
And actual determinations of *average* evolutionary change matches quite well the rate of evolution necessary to bring about modern life in the time available.
For example, from the talkorigins.org web source (I'd normally just provide a link, but the site is down at the moment):
Prediction 5.7: Morphological rates of changeI wish *any* of you folks would actually look at the available *scientific* literature, instead of just endlessly cycling the same creationist "urban legends". If you're going to try to critique science, shouldn't you actually *read* some first?Observed rates of evolutionary change in modern populations must be greater than or equal to rates observed in the fossil record.
Confirmation:
Here I can do no better than to quote George C. Williams writing on this very issue:"The question of evolutionary rate is indeed a serious theoretical challenge, but the reason is exactly opposite of that inspired by most people's intuitions. Organisms in general have not done nearly as much evolving as we should reasonably expect. Long-term rates of change, even in lineages of unusually rapid evolution, are almost always far slower than they theoretically could be." (Williams 1992, p. 128)In 1983, Phillip Gingerich published a famous study analyzing 512 different observed rates of evolution (Gingerich 1983). The study centered on rates observed from three classes of data: (1) lab experiments, (2) historical colonization events, and (3) the fossil record. A useful measure of evolutionary rate is the darwin, which is defined as a change in an organism's character by a factor of e per million years (where e is the base of natural log). The average rate observed in the fossil record was 0.6 darwins; the fastest rate was 32 darwins. The latter is the most important number for comparison; rates of evolution observed in modern populations should be equal to or greater than this rate.The average rate of evolution observed in historical colonization events in the wild was 370 darwins - over 10 times the required minimum rate. In fact, the fastest rate found in colonization events was 80,000 darwins, or 2500 times the required rate. Observed rates of evolution in lab experiments are even more impressive, averaging 60,000 darwins and as high as 200,000 darwins (or over 6000 times the required rate).
A more recent paper evaluating the evolutionary rate in guppies in the wild found rates ranging from 4000 to 45,000 darwins (Reznick 1997). Note that a sustained rate of "only" 400 darwins is sufficient to transform a mouse into an elephant in a mere 10,000 years (Gingerich 1983).
One of the most extreme examples of rapid evolution was when the hominid cerebellum doubled in size within ~100,000 years during the Pleistocene (Rightmire 1985). This "unique and staggering" acceleration in evolutionary rate was only 7 darwins (Williams 1992, p. 132). This rate converts to a minuscule 0.02% increase per generation, at most. For comparison, the fastest rate observed in the fossil record in the Gingerich study was 37 darwins over one thousand years, and this corresponds to, at most, a 0.06% change per generation.
Potential Falsification:
If modern observed rates of evolution were unable to account for the rates found in the fossil record, the theory of common descent would be extremely difficult to justify, to put it mildly. For example, Equus evolutionary rates during the late Cenozoic could be consistently found to be greater than 80,000 darwins. Given the observed rates in modern populations, a rate that high would be impossible to explain. Since the average rate of evolution in colonization events is ~400 darwins, even an average rate of 4000 darwins in the fossil record would constitute a robust falsification.Prediction 5.8: Genetic rates of change
Rates of genetic change, as measured by nucleotide substitutions, must also be consistent with the rate required from the time allowed in the fossil record and the sequence differences observed between species.
Confirmation:
What we must compare are the data from three independent sources: (1) fossil record estimates of the time of divergence of species, (2) nucleotide differences between species, and (3) the observed rates of mutation in modern species. The overall conclusion is that these three are entirely consistent with one another.For example, consider the human/chimp divergence, one of the most well-studied evolutionary relationships. Chimpanzees and humans are thought to have diverged, or shared a common ancestor, about 6 Mya, based on the fossil record (Stewart and Disotell 1998). The genomes of chimpanzees and humans are very similar; their DNA sequences overall are 98% identical (King and Wilson 1975; Sverdlov 2000). The greatest differences between these genomes are found in pseudogenes, non-translated sequences, and fourfold degenerate third-base codon positions. All of these are very free from selection constraints, since changes in them have virtually no functional or phenotypic effect, and thus most mutational changes are incorporated and retained in their sequences. For these reasons, they should represent the background rate of spontaneous mutation in the genome. These regions with the highest sequence dissimilarity are what should be compared between species, since they will provide an upper limit on the rate of evolutionary change.
Given a divergence date of 6 Mya, the maximum inferred rate of nucleotide substitution in the most divergent regions of DNA in humans and chimps is ~1.3 x 10^-9 base substitutions per site per year. Given a generation time of 15-20 years, this is equivalent to a substitution rate of ~2 x 10^-8 per site per generation (Crowe 1993; Futuyma 1998, p. 273).
Background spontaneous mutation rates are extremely important for cancer research, and they have been studied extensively in humans. A review of the spontaneous mutation rate observed in several genes in humans has found an average background mutation rate of 1-5 x 10^-8 base substitutions per site per generation. This rate is a very minimum, because its value does not include insertions, deletions, or other base substitution mutations that can destroy the function of these genes (Giannelli et al. 1999; Mohrenweiser 1994, pp. 128-129). Thus, the fit amongst these three independent sources of data is extremely impressive.
Similar results have been found for many other species (Kumar and Subramanian 2002; Li 1997, pp. 180-181, 191). In short, the observed genetic rates of mutation closely match inferred rates based on paleological divergence times and genetic genomic differences. Therefore, the observed rates of mutation can easily account for the genetic differences observed between species as different as mice, chimpanzees, and humans.
Potential Falsification:
It is entirely plausible that measured genetic mutation rates from observations of modern organisms could be orders of magnitude less than that required by rates inferred from the fossil record and sequence divergence.(References:)
Crowe, J. F. (1993) "Mutation, fitness, and genetic load." Oxford Survey of Evolutionary Biology 9: 3-42.
Futuyma, D. (1998) Evolutionary Biology. Third edition. Sunderland, MA, Sinauer Associates.
Giannelli, F., Anagnostopoulos, T., and Green, P. M. (1999) "Mutation rates in humans. II. Sporadic mutation-specific rates and rate of detrimental human mutations inferred from hemophilia B." Am J Hum Genet 65: 1580-1587. [PubMed]
Gingerich, P. D. (1983) "Rates of evolution: Effects of time and temporal scaling." Science 222: 159-161.
King, M. C., and Wilson, A. C. (1975) "Evolution at two levels in humans and chimpanzees." Science 188: 107-116.
Kumar, S., and Subramanian, S. (2002) "Mutation rates in mammalian genomes." Proc Natl Acad Sci 99: 803-808. http://www.pnas.org/cgi/ content/full/99/2/803
Li, W.-H. (1997) Molecular Evolution. Sunderland, MA, Sinauer Associates.
Mohrenweiser, H. (1994) "Impact of the molecular spectrum of mutational lesions on estimates of germinal gene-mutation rates." Mutation Research 304: 119-137. [ PubMed]
Reznick, D. N. (1997) "Evaluation of the rate of evolution in natural populations of guppies (Poecilia ieticulata)." Science 275: 1934-1937. [ PubMed]
Stewart, C. B., and Disotell, T. R. (1998) "Primate evolution - in and out of Africa." Current Biology 8: R582-588. [ PubMed]
Sverdlov, E. D. (2000) "Retroviruses and primate evolution." BioEssays 22: 161-171. [ PubMed]
Williams, G. C. (1992) Natural Selection: Domains, Levels, and Challenges. New York, Oxford University Press.