ABSTRACT
The urgency of modern biodiversity loss has created a crisis in modern taxonomy, and a compelling fear that we are losing Earth’s biodiversity faster than it can be discovered and described (Maddison et al., 2012; Wheeler et al., 2012). This is the motivation for efforts to increase the pace of taxonomy. But this biodiversity crisis has a context. To better understand biodiversity loss, we can look to previous experience of extinction throughout Earth’s history. All lineages have evolved, persisted, and most have perished, in environments that were quite different, at times much warmer or much colder than present average temperatures (Willis et al., 2010). Our ideas of what species mean, and how species work, cannot be inferred from the living biota alone: the species we interact with are just a horizontal slice through their larger, time-vertical distribution (Chapter 2). The process of comparing diversity through time intersects with understanding the nature of extinction, how the nature of extinction conceptually compares between fossil and living lineages, and how we measure both biodiversity and the loss of diversity.
