Absolutely nothing. Ok, so that’s not entirely true. But 99.9% of reactions to stress nowadays are harmful and unnecessary. Most of us have heard that the physiologic (body) response to stress has evolved to run away from woolly mammoths or saber-tooth tigers or something along those lines. Here’s a whirlwind tour of what stress is doing to you and your body, why it sucks, and what you can do about it to have a happier, more kick-ass life. Well, ok, great, but we were also club-swinging unibrow-sporting troglodytes (word of the day for ya). Things have changed. So why on earth would morning traffic and work deadlines cause the same…