ABSTRACT
In chapters 2 and 7, we spent some time puzzling over the evolution, radiations, and extinctions of ‘shes, drawing some lessons from the past. One lesson applies to the very nature of the planet we live on: if Earth is stable, then stability certainly has wide limits. But there is a great problem in extending the lessons learned from the past into the future. That problem is global anthropogenic climate change. In ‘nishing this book, I felt the necessity to extend our studies to global changes that may affect ‘sh distribution and abundance in the twenty-‘rst century. Most of the anticipated changes are familiar because they have occurred in the past. However, the difference is likely to be the speed and extent of change due to human in¤uence.
