Why Do We Need More Mutational Mechanisms?

In his model, i needed more powerful mutational mechanisms. Why didn't the organisms die when they had too much mutation? In other words, nature is tremendously wasteful. So that one one y to to get, the cambrian explosion, for example, you get this tremendous variety of fossils. I've looked at the birches sail up in the canadian rockies. Its fantastic stuff. And supposedly, only one of these creatures is the ancestor of all the ver its,. But looking at the fossil, it doesn't, a priori, look like this should be the successful idea - but it turned out that's how it worked.