First off, I'd like to give a shout out to my boy, Jupiter. Over the course of our solar system's history, millions upon millions of asteroids, comets, and meteors have swung by Earth. On occasion, a few struck us. When that happened, entire ecosystems were wiped out, and millions of years were needed in order to recover.
But with the millions of large, high-speed rocks floating around our sun, we should expect that the number of them that impact Earth to be relatively high. Not so. It turns out that Jupiter, with it's massive gravity and its orbit that sits outside of ours, has acted like a bullet shield for us, sucking up massive numbers of meteorites and asteroids. It is probable, in fact, that life on Earth is simply a puny little quarterback, and the success of life here is simply because we had a massive offensive guard running block in front of us.