Most people's definition of "evolution" includes the unsubstantiated claim that such minor changes over time means that an amoeba can become a dinosaur, given a few million years.
Billion, not million. There is a big difference.
I acknowledge that "adaptation" can change the physical characteristics of any species within a 'family' of creatures over generations when environmental changes also mean a change in diet....each is equipped to make those changes naturally as a survival mechanism (e.g. Peppered Moth or Darwin's finches)......but it is a fact that science cannot take the small changes that occur in one species and claim "evolution" on a macro scale, as if one family of creatures can become a different family, given enough time......and then treat that idea as if it must be a fact. (e.g. whale evolution, where the first "whale" was claimed to be a four legged furry land dweller, the size of a dog.) This is an assumption......not the same as a fact at all.
First, the changes in finches and moths were *genetic* changes. This is different than individual adaptation. It is a change of *species* since the different finches cannot interbreed (or, like lions and tigers, give sterile offspring).
Now, what mechanism *prevents* further changes from happening after speciation occurs? What prevents large scale change from happening because those smaller changes add up over generations?
So, we see otters adapting to a more and more water-based lifestyle. Do you not see it as *possible* that in another 10000 generations they will be able to stay under water for longer and not go back to land at all? And then that they will become more streamlined so as to move through water even better than they do now?
And, to bring it back to the whale ancestors, what is the barrier for a land based animal adapting over generations to living more and more in the water? Especially when we have the fossils showing the changes involved?
But lets also add that there were NO whales anywhere prior to 50 million years ago. But, at that time there *were* animals that showed similarities in their skulls and shared unique characteristics in their ears to modern whales.
Now, modern whales came from *somewhere*. They clearly had an ancestor 50 million years ago. But there were no whales then. So the ancestor 50 million years ago was NOT a whale as we currently see them. The *evidence* based on similarities of skulls is that certain land animals, Pakicetus and ambulocetus were those ancestors.
I believe that the line gets blurred even for scientists keen to get their evolutionary message across. (some relishing the idea of killing off God for good) But, when does science fact become science fiction?.....evolution is a classic example IMO.....not that gradual changes occurred in any given species over time, but at its very foundation where claims are made and real evidence is missing......lots of it.
It's always good to have more evidence. But there is enough evidence to show the broad patterns. Species change over many generations. All species today had ancestors 50 million years ago and many we would not recognize as being in the same 'kind' as the animals today. That is evolution.