['Remember that according to evolution, species don't change into ideal forms, but into whatever form is most advantageous at a specific time. In other words, there were probably some very specific advantages to become land mammals for a while, and that reason might have disappeared, or a better reason might have appeared for them to begin to go back into the ocean.']

Appeared to whom? Or is it to what? Did the whales weigh their options? Discuss it amongst themselves? Take a vote? Made it a voluntary choice? Or was it evolution that decided it? If evolution, what thought processes went into it? How was the decision made? How was the decision ever thought necessary to make in the first place? Wisdom? Knowledge? Experience? If exeperience, from what? Memory? That evolution must be one smart cookie, unless the whales decided on their own of course.