In most of the examples discussed in chapter 5, we saw a close match between the characteristics of organisms and their environment. However, natural selection does not always produce an optimal, or even a good, fit of organisms to their environments. To verify this you need only reflect on the fact that most of the species that have existed are now extinct. What are some of the reasons for a mismatch between organisms and environments? Develop your explanation using the environment, the characteristics of organisms, and the nature of natural selection.