It looks like someone at yahoo.com made an adaptation of adaptation, or just chose to use the less common adaption:
Some dictionaries don’t recognize adaption as a legitimate word. Others cite adaption as a variation of the preferred adaptation. Are they both correct? According to Grammarist:
… the longer word, adaptation, is preferred by most publications and is much more common. Adaption is not completely absent, but it usually gives way to the longer form in edited writing.
Aha! The word adaptation is the preferred option in edited writing. That explains why adaption appears on Yahoo!.