Four-legged or no legged, big or small, ambling or slithering, whatever forms the natural dangers took, our ancestors seemed to have known how to deal with them. Not only did they deal with them effectively, be it elephant, snake or crocodile, they also passed down their knowledge, sometimes ingrained in stone to posterity.

It is an image that Amos Nachoum can't forget. An image that this tough-as-boots adventurer who has been up close with some of the most dangerous predators on earth, acknowledges still moves him beyond words. It happened when the Israeli-born photographer was on a National Geographic expedition in Norway in 1997-98, diving in icy waters to photograph the orcas.