DAVID: There is a link in adaptations. We don't know how they might lead to speciation, since there is no Darwin-desired step by step fossil pattern.

dhw: As on the “whale” thread, yet again: nobody knows what causes speciation, and we can only offer our hypotheses. However, taking your favourite example of the whale, if a land mammal changed its environment, moved into the water, and became a different species,how can you then claim that there is no link between speciation and the environment?

As I've explained today the link is the other way around than your thought: prior speciation allows the animal to enter a new environment.