1.1: Introduction to What is Conservation Biology?

Popular interest in protecting biological diversity—which describes the amazing range of species, genetic diversity within each species, and the multitude of Earth’s complex biological communities with their associated ecosystem processes—has intensified during the past few decades. During this time, scientists and the public have recognized that biological diversity (often shortened to biodiversity) is being lost at increasing rates. Across the world, human activities are destroying ecological communities that have developed over millions of years. Over the next several decades, thousands of species and millions of populations will likely go extinct.

Figure 1.1: East Africa’s great migration is one of the most famous wildlife spectacles on Earth. Each year, tens of thousands of tourists from around the world flock to the region to see the 1.7 million common wildebeest (Connochaetes taurinus, LC) and hundreds of thousands of other plains mammals make their way from Tanzania’s Ngorongoro Conservation Area, through the Serengeti Plains, to Kenya’s Maasai Mara National Reserve. Photograph by Daniel Rosengren, https://commons.wikimedia.org/wiki/File:Wildebeest_Migration_in_Serengeti_National_Park,_Tanzania.jpg, CC BY 4.0.

The fundamental driver of all the biodiversity losses we are currently witnessing is a rapidly expanding human population coupled with increased consumptive needs. In 1850, after roughly 300,000 years of Homo sapiens on the planet, there were around 1 billion people on Earth. By 1987, not even 140 years later, the world’s human population had surpassed 5 billion. By 2021, there were 7.9 billion humans globally. With this many people, the human population grows by tens of millions of people each year, even with modest population growth (Figure 1.2). In many parts of the world, this is well beyond the ecological capacity of the region to support.

Figure 1.2: Human world population since 1800 with projections of future population (By Bdm25 - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/inde...curid=89215845)

To survive and prosper, people use natural resources. They harvest and use oil, water, and wildlife products, and convert natural ecosystems for agriculture, cities, roads, and industrial activities. This consumption, which reduces natural habitat and the associated wildlife populations, is intensifying because of the demands of a rapidly increasing human population. Consumption of resources also increases as countries develop and industrialize: the average citizen of the USA uses five times more resources than the average global citizen, 11 times more than the average Chinese citizen, and 32 times more than the average Kenyan citizen (Worldwatch Institute, 2015). This growth in the number of humans, together with their ever-more-intensive use of natural resources, is the fundamental driver behind most current species extinctions.

For conservation biologists and other nature lovers, the widespread extinctions of species and destruction of natural ecosystems are incredibly discouraging. But it is possible, and indeed necessary, to find ways to ensure the persistence of biodiversity. Actions taken, or not taken, during the next few decades will determine how many species and natural areas will continue to survive. Someday, people will likely look back and say that this time—the first half of the 21st century—was an important and exciting time when people worked together, and acted locally and globally, to prevent the extinction of many species and ecosystems. Examples of successful conservation efforts are described throughout this textbook.