Bonnethead fish control pitching (up-and-down motion of the body), yawing (the side-to-side motion), and rolling. Most hammerhead sharks do not yaw or roll and achieve pitch using their cephalofoils. The smaller cephalofoil of a bonnethead shark is not as successful, so they have to rely on the combination of cephalofoils and their large pectoral fins for most of their motility. Compared to other hammerheads, bonnethead sharks have larger and more developed pectoral fins and are the only species of hammerhead to actively use pectoral fins for swimming. Using data from mtDNA analysis, scientist have found that evolution of hammerhead sharks probably
What Is a Nation? French citizen has to have forgotten the massacre of Saint Bartholomew, or the massacre that took place in the South in the thirteenth century. While many nations, such as France, begin with a feudal regime such as a monarchy, others, such as the United States and Switzerland, are formed by acts of consensual aggregation. France and many others, however, survived their feudal roots while maintaining their identity. Renan inquires what is the organizing principle? It can't be race, because France is "Celt, Iberian, German...The most noble countries, England, France and Italy, are the ones where the blood is most mixed."