The Sea Snail,Littorina Saxatilis,is Found on the Coast of Northern

Multiple Choice

The sea snail,Littorina saxatilis,is found on the coast of northern Spain.The snails further upshore are large with heavily ridged and banded shells,and share a border with the snails further downshore that are smaller with smooth,unbanded shells.If the upshore and downshore snails were to become separate species,this would be an example of _____ speciation.

A) sympatric
B) parapatric
C) prezygotic
D) allopatric
E) postzygotic