@neologist,
Evolution is often, as Miller says
1Being at the right place at the right time
2 TAking whats already there and doing something new with it.
Thus the whale. The only thing I think we should be more considering of is that one of the early "LAWS" of evolution candidacy as verbalized by RAup is that " being a candidate for evolution rather than extinction is usually directly proportional to the number of species in ones genus. So Indohyus may have been a genus with a number of species, each with a minor niche adaptation that made one or more of them learn to love being a MARINE ANIMAL.
We haven't found all these "cousin" fossils as of yet so we cant, in a strait face stand around and pour all of our evolutionarily needed traits onto little Indohyus. He just has about 5 or 6 adaptations that are more precetacean than not (and his fossils were clearly indicating a marine affinity) in the ancient Indian sub continent alongside the nasty firey landside conditions that Indohyus may have learned to escape.
I always like to go back to the Polar bear where we clearly have an example of macroevolution in limits of times that could have been observed by ancient humans.
