Decisions made by Colonial era settlers to dam Connecticut waterways triggered sudden and parallel evolutionary changes in two species of fish competing for food, a new study shows. Earlier studies documented the decrease in size and changes in gill structure of members of the alewife species cut off from access to the sea in newly dammed lakes. The new study found similar changes in feeding habits of the bluegill, which also showed greater ability to feed on smaller zooplankton found in landlocked lakes the species shared with the alewife....