Ironically, Ken Ham’s statement that evolution is historical and requires a history is in fact correct. Hoist on his own petard the same would be true of the biblical ‘histories’. But the point emphasized repeatedly in WHEE is that there are limits to observation. The case of whales mentioned forces us to consider this: we see the clear sequential record of whales via the fossil record, but can we really conclude that Darwin’s theory of natural selection is behind this? Biologists are unfair: this claim is actually extravagant and they can get away with it because they don’t really have to prove it. Proving it would be VERY hard: a detailed historical record of the millions of years of whale evolution, sampled at, what? hundred year, hundred thousand year, million year intervals. Such a dataset is completely hopeless. We can ‘observe’ in order to verify a theory’s claims.
Check out http://history-and-evolution.com/whee4th/chap2_2_1.htm: The Limits of Observation