Resolving time in paleobiology

Abstract

Time is so fundamental to the everyday thinking of paleobiologists and geologists that it is seldom given close critical attention. Many of the currently debated issues in evolutionary history—catastrophic extinctions and punctuated vs. gradual morphological change, for instance—include assumptions about time and rate which are seldom made explicit. Methods now exist for calibrating evolutionary patterns through estimates of time components in the fossil and sedimentological records. There is a growing realization that increased precision in defining time frameworks can greatly clarify evolutionary problems. This has helped to stimulate renewed interest in the traditional topic of time and how it is represented in the biological and geological record.