week 12, the ethics of gene therapy

I really don't feel like I know enough about this to have a respected opinion, but I'm basically pretty sqeamish about healing modalities that are dependent on killing something else. Who are we to decide that we're more important than the mice? Although if it's something that was dead anyway I feel better about it. A yoga teacher who I've really appreciated through the years has a knee problem that people have recommended he take shark cartilege for, but he's a staunch vegan and would rather live with the pain than kill sharks, and while I personally just might take the shark cartilege if it were me, I really admire his sticking to his principles. And even if gene therapy is going to save countless lives, it begs the question -- do we really want to save those lives? The planet is overpopulated as it is, what is so bad about people dying? And of course we are attached to each other, and don't want someone we love to die, but how far are we going to go to keep them from dying? And then, at some point, they are going to die anyway. Conversely, we are killing things all the time, by living, we're eating other organisms, we're stepping on them, we're chopping them down to make furniture out of them...I'm not going to be like the people of a religion in India, I forgot the name right now, who wear scarves over their mouths so they won't breathe in bugs and thus, kill the bugs, and they sweep in front themselves as they walk so they won't step on a bug -- you could drive yourself crazy trying not to harm anyone. So I don't know where to draw the line.