There's something really important about sharks:
Sharks have two senses that many animals do not have:
- Electroreception: The Ampullae of Lorenzini are small pits in the head that detect electricity. The shark has the greatest electricity sensitivity known in all animals. This sense is used to find prey hidden in sand in bottom feeding sharks, by detecting the nerve impulses. It is this sense that sometimes confuses a shark into attacking a boat: when the metal interacts with salt water, sharks can detect the resultant electrical charge from over one mile away.
Source:
http://en.wikipedia.org/wiki/Shark#Shark_sensesThis could explain why the Dharma scientists attached importance to sharks genetic study.