Evolution does NOT mean quantum changes. That means changes happen quite slowly. Evolution does not predict that change will happen in a single generation. In fact, the term evolution means gradual change. So, even though amphibians evolved from a fish. It took millions of years to accomplish the change, about 10 million years between fish that are ancestral to amphibians and the very first amphibian.
There are a lot of generations in those 10 million years. Of course, it does not mean that all of the changes from one species to another will be spread out evenly over all those years and generations. Sometimes changes can happen quite quickly, and sometimes there is no change at all for millions of years. It depends on the environment. If the environment changes rapidly, animals must also change rapidly, or else they become extinct. In fact, many species have become extinct without leaving any descendants. Most of the arthropods found in the Burgess Shale about half a billion years ago have no leaving descendants. Only a handful of the arthropod lineages are able to persist to the present.
Creationists have no understanding of evolution, and they are raising nonsensical and strawman arguments which they claim to disprove evolution. These arguments are not based on fact, but are based on their misrepresentation of evolution.