Biodiversity loss: the greatest challenge

Biodiversity loss is probably the greatest challenge facing humanity today. This challenge was already apparent during the second half of the past century, and its realization crystallized in the Rio’92 Earth Summit. However, the wave of sympathy and action awakened by Rio Summit has faded over time, and progress towards its goals has been moderate at best.

Today, and despite ambitious policies such as the “2010 goal”, rates of biodiversity loss keep growing at an increased rate. With the world’s attention almost exclusively focused on climate change, a recent review focused on identifying planetary boundaries for human welfare identified Biodiversity loss as the most critical. Extinction rates, which surpass sustainability standards by several orders of magnitude, compromise the ability of ecosystems to sustain human necessities and severely aggravate the impact of other stressors. Our capacity to face the challenges posed by climate change, food and health security, or population growth, to cite but some of the most important, will critically depend on our ability to slow and finally halt biodiversity loss.

The mention made to extinction rates measured over recent evolutionary history pinpoints the background setting on which biodiversity is continuously generated and loss. Evolutionary processes are ultimately responsible for the generation and maintenance of biodiversity, and provide the thread that integrates the various organization levels at which it is defined: genetic, species, community and landscape.

Evolutionary forces built and shaped extant biodiversity over historical times, and the genetic makeup of today’s populations and species is a manuscript in which we can read its ancient and recent signatures.

Evolutionary processes are affected by human action, with unforeseen (and often unwanted) consequences on species, communities and even ecological processes. Think for example of the selection pressures exerted by commercial fisheries or the game industry, on the phenotype and life-history of their target species.

Evolutionary processes, finally, may hold the key to improve our responses to global change. The growing literature on contemporary evolution illustrates how surprisingly fast evolutionary responses can be. In a rapidly changing world, the capacity to understand and anticipate these responses could provide us with a badly-needed tool to navigate the unexpected.

Evolutionary processes can therefore be of pervasive importance. However, they are rarely incorporated into biodiversity conservation and management, even less into policies aimed at ensuring the sustainable use of natural resources. One of the obvious reasons should be apparent to all of us: the complexity of these processes will only add to the pervasive complexity of the ecological and socio-economic systems targeted by these policies.

Times are nonetheless exciting: during the last decade, the development of powerful analytical tools in the fields of molecular and population genetics, remote sensing and information technology have facilitated a revolution in the study of evolutionary and ecological processes, and the time is ripe to facilitate their integration into ongoing management actions.