"Why do you think it took nearly twenty years for P.E. to gain even modest acceptance?"
Because evolutionists that were not paleontologists were terribly ignorant about the fossil record, having been misled by their own propoganda.
Take a close look at the following quote, and notice how at this particular conference, most were simply unaware of what the fossil record actually contained.
"The absence of transitional forms between established species has traditionally been explained as a fault of an imperfect record, an argument first advanced by Charles Darwin. The accumulation of sediments and the entrapment and fossilization of animal bones is, at best, a capricious process: as a result, geologists are familiar with the difficulties of reconstructing past events. According to the traditional position, therefore, if sedimentation and fossilization did indeed encapsulate a complete record of prehistory, then it would reveal the postulated transitional organisms. But it isn't and it doesn't.
This ancient lament was intoned by some at the Chicago meeting: "I take a dim view of the fossil record as a source of data," observed Everett Olson, the paleontologist from UCLA. But such views were challenged as being defeatest [sic]. "I'm tired of hearing about the imperfections of the fossil record," said John Sepkoski of the University of Chicago; "I'm more interested in hearing about the imperfections of our questions about the record." "The record is not so woefully incomplete," offered Steven Stanley of Johns Hopkins University; "you can reconstruct long sections by combining data from several areas." Olson confessed himself to be "cheered by such optimism about the fossil record," and he listened receptively to Gould's suggestion that the gaps in the record are more real than apparent. "Certainly the record is poor," admitted Gould, "but the jerkiness you see is not the result of gaps, it is the consequence of the jerky mode of evolutionary change."
To the evident frustration of many people at the meeting, a large proportion of the contributions were characterized more by description and assertion than by the presentation of data. Nowhere was this a greater source of irritation than over the issue of stasis. Not until an unscheduled speaker - Anthony Hallam of Birmingham University, England - came forward with a blackboard sketch of the paleontological history of Jurassic bivalves did many people begin to be convinced of the importance of stasis. Hallam's intervention was much appreciated. However, there were still some reservations: "That's all very well for marine invertebrates," challenged a skeptical voice, "but what about land animals?" "I can show you many good examples of stasis in terrestrial mammals," offered Elizabeth Vrba of the Transvaal Museum, Pretoria.
Thus went the verbal jostling, with the mood swinging perceptibly in favor of recognizing stasis as being a real phenomenon. Gabriel Dover, a geneticist from Cambridge University, England, felt strongly enough to call species stasis "The single most important feature of macroevolution." [See following note.] In a generous admission Francisco Ayala, a major figure in propounding the Modern Synthesis in the United States, said: "We would not have predicted stasis from population genetics, but I am now convinced from what the paleontologists say that small changes do not accumulate." [Note: Dr. Ayala denies that he said this. Please see the letter reproduced below from Richard Arrowsmith and Dr. Ayala.]"
http://www.theistic-evolution.com/lewin.html
Regardless of the one particular person's retraction/denial or mistake by the writer, one thing is clear. Stasis is argued by PE advocates and demonstrated by paleontologists, and most of the rest have a hard time accepting this data, but eventually most concede the fatcs do indeed show stasis as a real phenonmenon. Why did they have a hard time accepting stasis?
I think it is because they never really objectively examined the fossil record.
