Clearly humans can eat meat, and have been eating meat for thousands and thousands of years, and have been thriving quite well on that diet. Archeological evidence suggests it wasn't until the later stone age and iron age that caries became a problem, perhaps due to eating more carbohydrate rich and processed foods. The people in the early stone age had bigger bones as well. (Of course, they also got a lot more exercise back in those days. Okay, and on average only lived until they got to be around 25-40 years, but that was likely due to all the fighting with sabre tooth tigers, wolves, bears, and dinosaurs.)
Also, God (the Christian one, the others are obviously fake) said that we could eat meat after The Flood. And God rejectred Cain's vegetable sacrifice, but praised Abel's lamb sacrifice. Also, God-fearing good old boys such as the benevolent General Franco of Spain strongly discouraged vegetarianism and denied vegetarian restaurants to do business.
Also, meat has the essential B12 vitamin which is not found naturally in plant foods. And fish has long chained omega 3s and vitamin D. So it would seem eating meat is natural, especially the paleo diet.
Also, animals kill and eat each other, so how can it be wrong for humans, who are animals, to kill and eat other animals? Isn't that only natural?
So what is the vegetarian response to this?
(Disclaimer: These opinions are not my own; I'm just trying to encourage discussion of a topic that may be of interest to many new vegetarians and the vegetarian-curious!)