Respectfully I have to disagree with your premise that we humans have evolved into meat eaters. You state that the human being has evolved in ways that indicate that we are capable of eating meat such as producing hydrocloric acid and the such. While this seems likely to be the case I dont understand how this evidence can be used to ignore other evidence that we probably should not be eating meat. Clearly the human body does not digest meat efficiently or properly. If you want to use evolution as proof that we can eat meat then I dont think you should ignore the fact that humans have not evolved well. I am not very knowlegeable on animal physiology but I do know that carnivors have very short and wide intestines for easy elimination of waste that us humans have not evolved to have.
As for tool usage, I believe our ability to use tools just made it easier for humans to do something that wasnt previously easy to do. It doesnt make it proper that we do so. I dont really understand how tool usage has anything to do with our evolving into meat eaters other than simply making it possible for us to eat meat.
Perhaps someday we will evolved to fully be able to properly digest meat and eliminated its waste but right now we cant. I enjoy eating meat and I dont believe it is something I will ever change. I believe that it is not completely unnatural for me to eat meat but in the same breath I am not going to tell you that I believe that eating meat is the best thing for my health. Since one of my vices is eating meat and will continue to be so, I simply understand that there are things I must do in order to remain healthy. I cant ignore the adverse effects of eating meat just because some fossil record and a very basic incomplete understanding of human evolution may indicate that it is natural for humans to eat meat. The proof is there that eating meat does not do the body good over the long run. I cant ignore that proof. I cant ignore my own body and the things that it needs to help it be healthy.
MH advocates a lifestyle that even he admits he is unable to keep up with. I am not convinced that humans should only eat berries and nuts and the such anyway. All of this of course is irrelevant since I have made decisions as to the lifestyle I choose to lead. What is relevant is that I understand that the lifestyle I have does damage my body and that I need to do other things in order to remain healthy or as healthy as possible within that lifestyle. I believe most people come to these forums to not make massive life altering changes to be in peak health but to make changes and small sacrafices in order to improve their health.
I appologize if this is argumentative. Its not my intention to create a fight but to point out that we are all here because there are health problems that we have and we wish to correct these problems. There is a HUGE neon arrow pointing at animal products saying that they are largely to blame. For the many who are here who choose to eat meat but still wish to be healthy, we cant ignore the neon arrow or delude ourselves into believing that the problems are not animal related simply because we draw conclusions that humans evolved in ways that indicate that we should be able to consume meat.