Insect Mouthparts
Here is a closeup of a grasshopper's mouthparts. You can see how ancestral appendages (legs) have
been modified by natural selection to the function of food processing. The ancestral segments that held
these appendages have fused to form the grasshopper's head. The front mouthparts, once appendages
on the left and right side, have also fused together to form central flaps (the CLYPEUS and the
LABRUM) to hold the food in place while it is chewed and swallowed. This is a good example of
EXAPTATION, the use of pre-existing body parts with one function as raw material for the
evolutionary development of new functions.