The examples for selection given above (Finches, Iguanas, peppered moth) are based on observations in the field. They obviously only give evidence for microevolution. It is often said, that more complex structures developed by selection, as well as the slight changes of beak size, leg length or wing coloring in the given examples. Often the hypothetical acquisition of new organs is described as “adaptation”, as well. That way it is suggested, that selection (in combination with mutation) can be made responsible for the acquisition of organs – and that the emerging of new structures is basically understood.
Wings for instance would then be an adaptation to flight or a long, sticky, protrudable tongue to nutrition with small insects etc. This way of expressing oneself is common but nevertheless factually incorrect. The term adaptation can only be used in the sense of a fine tuning: An already existing wing might be adaptive to the different requirements of flight. But a wing itself is as much an adaptation to flight as a washing machine is to the washing of dirty clothes.
Here the adequate use of the term is important: Wings are not an adaptation, but equipment for a certain purpose, constructions, by which certain tasks can be fulfilled. Actually, the development of new organs by selection (and other evolutionary factors) never has been observed. Selection is a factor of variation, not of creation.