We humans are no longer 1PARTICULAR hairy. We do, however, retain patches of this uniquely 2MAMMAL structure in a number of places. Among mammals, only dolphins – after they’ve shed the few whiskers they’re born with – are completely bald. For most mammals, hair is 3ELEMENT. It is vital to their warm-blooded 4LIFE. And, certainly for the first mammals – tiny little creatures that lived about 200m years ago – acquiring fur coats that slowed down heat loss was 5NEED for the evolution of warm blood. It is, though, still 6CERTAIN how hair first evolved – the usefulness of a few straggly prototype hairs is hard to fathom. They certainly wouldn’t have kept anyone warm. It’s now thought that these fine 7PROTRUDE may originally have acted as sensory structures, like whiskers do today. They may alternatively have been wicks for getting sweat-like 8SECRETE out of the sweat glands and onto the body. And that only later did a thicker coating of them became insulating.