Why doe hammer head sharks have such an unusual shaped head?
Among shark biologists, this is an old question that still requires a good answer. As some answers you have received show there has not been a lack of theories, but none really convinces entirely. Lift, maneuvarability, or sense of smell are not particularly different in hammer heads than in any other sharks. *Sphyran lewenii* is a big, major predator and does not only feed on small prey, so the notion that all hammer heads have an advantage in finding small prey hidden in the substrate is actually not sustained. It seems that we simply have to settle for the fact that we do not know. I think that the best explanation to be made is not at all related to adaptation, but rather to a phenomenon referred to as neutral evolution. Unforunately, biologists only too often think that all evolved structures, behaviors etc. are adaptive, i.e., it serves a particular purpose. There are, however, numerous cases where research has shown that characteristics evolved without any advantage, but for pur
