Anxiety Disorder and Evolution

When my body seems like it's not helping me, I start to think why that is. Aren't our bodies (in

an evolutionary sense) supposed to keep us alive so that we are able to be fruitful and multiply? The day after I went into aniphilactic shock after taking an antibiotic called Levaquin, I felt betrayed. Why do our bodies react in this way? If I was a caveman and had no access to an epi-pen, I would be a goner! And well, that's when it hit me. In Darwin's eyes, I was not a fit person. But then again, cavemen didn't have access to Levaquin either!

"What's the evolutionary advantage of being allergic to something?" I asked my biology teacher.

"Well," she considered, "it's the body's way of telling you never to go near that allergen again."

I still wasn't satisfied. My caveman self would be dead and not get another chance to go near that allergen again.

I researched a little and stumbled upon a quote I liked:

"The important thing to note here is that... just because a feature has evolved does not necessarily mean it has a purpose." -Ethan Benatan

http://www.newton.dep.anl.gov/newton/askasci/1993/biology/bio002.htm

It still irks me a little bit though. Ever since I first learned about evolution, I think of everything biological in an evolutionary sense. It's a hard habit that I can't shake. However, I do believe another lucky gene I have received from my bloodline did have an evolutionary advantage.

I was a born strange. Everyday I thought I was dying. I thought the people at the Cheez-It factory poisoned my beloved snack. I never wanted my parents to go to a gas station because I was positive that's where murderers hung out. I was always sensitive to any environment I was in. It wasn't until I was 8 when doctors finally put a name to it. They told my parents I had Anxiety and Panic Disorder. It actually left me in peace for a while but then reared it's ugly head when I was in high school. Again, I felt like damaged goods. Not a fit specimen so to speak. But to make myself feel better, I came up with this theory.

Anxiety and Panic disorder would have been a good thing to have, if it did exist in caveman days. Someone who was hyper aware of their environment had a better chance of not becoming a meal than the person who let their guard down for a split second. They then lived to pass on those lovely genes to me.

But it leaves me with questions. Did some of our way ancient ancestors have any kind of mental illness? How did mental illness come about? Are we the only animals that can get this disease? What would be an evolutionary advantage to, say, schizophrenia?

These are tough questions that I think even the smartest scientists would have a hard time answering. 

About that schizophrenia thing though...click here.