&gt; In a scientific first, researchers have just reproduced what a dolphin saw as it encountered a male diver.<p>I wonder why they specified that it was a male diver? Would a dolphin&#x27;s echolocation be able to tell a male human from a female human? The resolution doesn&#x27;t look high enough to distinguish external genitalia, but maybe differences in internal composition (such as body fat) might change the character of the echoes sufficiently to distinguish?