Again, as shown on page 3, isolation can result in a daughter species that lives alongside, in time, its ancestor species, or an ancestor species that actually outlives its daughter species. If the ancestor species is isolated in an area where fossilization does not occur, while the daughter species lives in one where fossilization does occur, the daughter species would appear in the fossil record before its ancestor species, if the ancestor species ever appeared at all. Put another way, the fossil record shows only when that specific animal lived and died, NOT when that particular species evolved. The existence of an ancestor species later in the fossil record than a daughter species simply means that the lineage extends farther back in time than shown by the fossil record. As I understand it, it states that animals remain in a static state until environment pressure causes evolution.
Evolution then occurs quickly.
The more extreme the environmental pressure, the more extreme and the quicker the changes. Studies of extant animals show that this is indeed the case. One example is the Galapagos Finches. A severe drought in the mid 70s brought about conditions that favored the large beaked morph. Within a generation or two, nearly all the finches were of the large beaked type and the small beaked were on their way out.