Forget asteroids, technology will be the downfall of humankind

And I don't mean robots/androids on a homocidal streak. I'm talking about normal everyday technologies. I admit that these technologies provide great comfort (although comfort is a relative feeling, just ask those tropical foragers) and that without them, we would all be living in small villages living off the land. But this also means we would be seperating populations of the human species in all different environments and promoting diversity in the process. Now, thanks to globalization and technologies such as trains, cars, planes, boats, tv, phones etc, we are more connected with the world than ever. This is a great thing for world trade and it is also good of a little interacial breeding. You know that joke where in the future everyone will be have beige skin? Well, that could very well happen and it wouldn't stop at skin color. It would also include similar immune systems and physcical appearance and genetic dispositions etc. Do you know that classic example of evolution with the peppered moths of industrial England? What do you think would happen if all the moths were white and the trees suddenly became covered with back soot. All I'm saying is that maybe there is some biological purpose to our parents wanting us to marry people of the same race beyond just cultural similarities. Maybe this will preserve differences, differences that could very well keep our species going for the next millions of years. Too bad it isn't going to be an asteroid that kills us because unless Bruce Willis has a time machine, I don't see much we can do to stop this slow but persistent process.