From a dental standpoint, humans' teeth are equally suitable for eating meat and plants. We have incisors, capable of cutting into meat and vegetable matter, canines (not present in herbivores) suitable for tearing meat, bicuspids suitable for grinding and tearing meat and vegetables, and molars suitable for grinding both again. Our saliva contains enzymes such as lipase and amylase, fat- and protein-reducing enzymes suited more to a carnivorous diet. Yet, as Erenteta quite rightly pointed out, our digestive tract is more suitable for a herbivorous diet. Our jaws also move horizontally as well as vertically, a feature in many herbivorous (and omnivorous) animals and relatively few carnivores. All in all, we're a bit of a mixed bag of a species.

Consider the following point, however. Mammalian herbivores have evolved with their eyes on either side of their heads, providing almost a 360-degree field of vision. Herbivores tend to be docile (in general), and are therefore likely prey for their carnivorous predators. Their wide field of vision enables them to eat and to keep a constant watch-out for predators. Witness the antelope, mouse and even the rhinoceros for proof.

Carnivores and omnivores, on the other hand, have evolved with eyes at the front of the head, with an overlapping field of vision. This provides stereoscopic vision with depth-perception, essential when chasing down prey or sizing up a potential kill. And guess what? Humans fall into this category, along with tigers, wolves and countless other heartless killing machines.

We have evolved as hunters. Over the millennia, our intelligence has enabled us to create weaponry and clothing, changing us from apish, feral, hairy primates to the weak, relatively defenceless species we are today. Surely that is evolution? Some birds started to build nests, so they evolved to be dependent upon nests. We don't accuse them of assuming control of their own destiny. An interesting effect of our intelligence is that we are able to design new diets capable of supporting us without the consumption of meat, even though we as a species have been eating meat since time immemorial.

The Romans ate meat, as did the Abyssinians, the Ancient Egyptians, the Ancient Greeks and countless other civilizations. Humans ate meat then and we are eating meat now, so the "suggestions" made by our physiology are nothing more than that. Suggestions towards a situation (humans as herbivores) proven patently incorrect by human history.

To sum up, primitive humans evolved to hunt, ergo to eat meat (in addition to plants). Our intelligence has hastened our evolution, weakening our bodies while sharpening our minds. And this rapid evolution has resulted in our ability to choose to be vegetarians (apologies to sufferers of animal protein intolerance who clearly have no such option). To me, the option to be vegetarian is little different to the option to use recycled products - it is an option, some people feel compelled - for a variety of perfectly good reasons - to take it, and no-one should be criticized for it.