The question of why me is usually rhetorical, especially when life has thrown something really difficult in our path that others don't have to grapple with.

This cry to God or the universe or nobody in particular

is mostly a way of acknowledging that we feel overwhelmed, but it can also be a first step in

the path toward understanding what has gone wrong for what reasons. From KERA in Dallas, this is

think. I'm Chris Boyd. My guest's greatest challenge came from something that

started out as a source of confidence and comfort. But the more he relied on alcohol to control

his emotions, the more his drinking came to be something that controlled his life. He's in recovery

now. And being a scientist by temperament and training, he wanted to explore the why me question literally.

Why can some people take or leave alcohol without developing a problem?

Why do some people become physically dependent on it?

And what can we know about all the gray area drinkers in between?

Dr. Charles Knowles is professor of surgery at Queen Mary University of London

and a consultant colorectal surgeon. His book is called Why We Drink Too Much, the Impact of Alcohol on

Our Bodies and Culture. Charles, welcome to think. Thank you, Chris, for having me. It's great to be here.

Why would human beings have evolved the ability to metabolize alcohol when it's often not good for us?

And there was a long time when we wouldn't even have been able to produce it ourselves.

Well, the established thinking on the subject is that we,

genetically evolved to metabolized alcohol by virtue of necessity about 10 million years ago.

So there are studies of the genes of our primate ancestors that show that the changes in our genes

to metabolize alcohol, particularly some genes can be mapped back through the ancestral DNA.

And for instance, chimpanzees and gorillas share with us the ability to metabolize alcohol whereas gibbons and

orangutans don't which tells you you know if you're at the zoo which ape you should

...