The most haunting of our imagined monsters remain hidden as they stalk us, striking when we least suspect it, while we are relaxing, or at play. The now-extinct megalodon roams the ocean unseen and unseeable, except in our imaginations. And it often surfaces in our consciousness when we are at rest or play by the seaside. The reason that the great shark holds such a chilling grip on us must be sought in the very long history of the interaction of sharks with people. Is there anything more spine-chilling than the thought of being eaten alive?
There is a contentious theory that our species went through an aquatic phase during its evolution, according to which the long periods our ancestors spent in the sea foraging for marine life account for our hairlessness, our thick layer of subcutaneous fat, and our abilities to swim and hold our breath. If the theory is true, then perhaps this primeval foray into the water has something to do with our deep fear of submerged predators.
