There was a time when humans stopped hunting for food - and started growing it. Complex food economies have been built based on farming. Since the domestication of animals, they have been bred not just for their meat, but for their by-products.

Humans have relied on animals for shelter and warmth, from wool, to silk, to leather. However, wearing animals for warmth is no longer a necessity, but rather is now a fashion statement.

Throughout history, humans have needed some extra muscle to get work done. From growing food, to heavy lifting, to transportation - before modern machinery, animals did the work. With technological advances, this is no longer the case.

If there is one function animals serve that hasn't been forgotten, it's companionship. Animals are pets, allies, and `man's best friend'. They are sources of happiness and comfort, and - despite domestication - stand as reminders of our wild roots.

Humans are now largely removed from nature but there is much to understand about the creatures. Germ-ridden, sharp-toothed animals are a fact of nature, and even with advances in medicine, basic survival instincts should not be forgotten.

Like no other species, humans have created and developed art, music and science. Animals are used as muses and test subjects in this creative process. But no matter their purpose, one thing is true - animals have helped us to flourish and thrive.