Chapter Eleven

What is the Future of Biodiversity?

Why study extinction and biodiversity loss?

Throughout this book we have seen that extinction is one of the key processes that have shaped the history of life and the development of biodiversity. Currently, species declines and extinctions appear to be happening much more rapidly than at any time in geological history, as a result of the way human activity is modifying the world’s natural systems. There is widespread, international consensus that action is needed to prevent further extinctions and mitigate ongoing loss of biodiversity. In order to develop effective strategies for conservation, we need to understand how biodiversity is distributed (phylogenetically and spatially), we need objective methods to quantify the speed and extent of biodiversity loss, and we need an understanding of the processes that cause the loss of biodiversity. In developing this kind of big-picture view of conservation, we can make use of some of the tools and knowledge gained from the study of macroevolution and macroecology.

 What are the main points?

• Using the fossil record, we can estimate a “background” extinction rate for periods between mass extinctions. Current, human-driven extinction rates appear be to orders of magnitude higher than background rates, and if continued, could lead to a global mass extinction event comparable to the “big five” from the fossil record.
• The IUCN Red List is the primary scheme for classifying species according to their inferred risk of extinction. So far, a few large groups of vertebrates have been fully evaluated under the Red List scheme, but much of the world’s biodiversity remains unevaluated due to lack of sufficient data.
• The central concept of biodiversity conservation planning is prioritization, because of limited resources for conservation programs and conflicting demands on the use of land. Prioritization can be species-based (which species should we prevent going extinct?) or area-based (which areas should we set aside as protected areas?).
• Systematic conservation planning is a structured, objective approach to making conservation choices such as choosing reserve networks, which aims to meet conservation goals efficiently, by minimizing the costs associated with conservation activities.
• Phylogenetic relationships among species have been incorporated into conservation prioritization by identifying species that are evolutionarily distinct (with few close living relatives), or groups of species with high phylogenetic diversity. However, it is important to be aware of the limitations of using phylogenetic branch lengths as a proxy for conservation value.

 What techniques are covered?

• Using the fossil record to estimate background extinction rates
• Using the Red List and Red List Index to estimate the extent and speed of current species declines
• Reserve selection algorithms using the principle of complementarity
• Calculating phylogenetic diversity (PD) and evolutionary distinctness (ED)

 What case studies will be included?

• Predicting conservation status of poorly-known species using comparative models

Image: LiquidGhoul, CC3.0