The Future of Life

Short for biological diversity, biodiversity is organized into three levels: environments, species, and genes. Biodiversity is greatest in environments where there’s the most solar energy, ice-free terrain, and climactic stability—like the world’s tropical forests, where half the world’s plants and animal species are thought to exist. While biodiversity is a function of the interplay between ecosystems, species, and genes, many biologists favor species as the unit by which to measure biodiversity, as in theory, they can be counted. Even if the exact number of species is unknown, there could be anywhere between 3.6 to 100 million species. 

The love of nonhuman life is known as biophilia, and it may be one of humanity’s basic instincts. This love of life is indiscriminate and applies to our fascination with unusual creatures, our interest in life on other planets, and our tendency to imagine emotional connections with animals. In Chapter 6, Wilson notes that an important aspect of biophilia consists of the innate preference of humans for certain types of habitat; research suggests many people are partial to natural environments, especially when these resemble the grassy savannahs of humanity’s earliest ancestors. By this logic, since human beings once depended on the natural world for survival—and still do, albeit in ways that can be less obvious—it is logical that we would also love it. The converse of this tendency is biophobia—the innate aversion to certain forms of life that signal danger, such as blood, snakes, and running water. 

The natural world can yield many materials that are valuable for human purposes; as Wilson notes in Chapter 5, the known species of one kind of fungi alone have yielded 85 percent of the antibiotics that are now being used. The investigation of biodiversity for useful compounds is known as bioprospecting, and with many species left to discover, there is reason to assume bioprospecting could yield ample resources. This practice is also less destructive than the purposes for which many environments are currently being used, and more efficient, economically speaking—the value of materials harvested through bioprospecting in tropical forests is several times the value of agricultural or logging yields from similar plots. 

There are several tools governments and non-governmental organizations can use to preserve habitat for conservation purposes. In Chapter 7, Wilson describes conservation concessions as a way of quickly setting aside land for conservation by having conservation NGOs bid for long-term leases on tracts of tropical forest. In Guyana, for example, the NGO Conservation International preserved part of the rainforest by leasing it from the government. In this way, the government generates money from the land, but the habitat is also preserved. Debt-for-nature swaps are another option in which money is fundraised to purchase a portion of a country’s commercial debt. This purchase in turn expands local equity and allows for the promotion of conversation, either by offering environmental education or by purchasing land for nature reserves. 

In Chapter 5, Wilson describes how ecosystem services—the materials and energy that are created by the natural world and sustain human survival—provide nearly inestimable value to human beings. Ecosystem services fall into four broad categories: the provisioning of food and fresh water, the regulation of the atmosphere and the climate, sustaining services like nutrient cycling and oxygen production, and recreational and cultural benefits. Replacing these services would cost tens of billions of dollars, but as Wilson notes, doing so is likely impossible in any case. As an example, he points to aquaculture, or fish farming, which is becoming increasingly necessary as wild fish stocks collapse but which has a negative effect on wetland habitats and diverts agricultural production from other uses. 

The filter principle refers to an element of the relationship between human activity and biodiversity decline. In Chapter 4, Wilson describes the process by which the movement of Homo sapiens around the globe led to mass extinctions, first of megafauna such as giant sloths and flightless birds and then of other species. The filter principle explains how these past waves of extinction affect the likelihood that a species living in a present day will go extinct. According to the filter principle, species that have faced threats before and survived are now more resilient. In those areas where humans arrived a long time ago, this means only the sturdiest species are left. In other areas, like Hawaii, where humans arrived relatively recently, there are more vulnerable species, and therefore there is a higher rate of extinction. 

Genetically modified organisms offer a way for an increasing human population to sustain itself on a planet with finite resources, offering, for instance, ways to produce crops without using insecticides and to modify staple crops, such as rice, so that they’re more nutritious. In his discussion on the value of biodiversity in Chapter 5, Wilson notes that biodiversity makes genetic modification possible, since wild organisms are a reserve of genetic material that can be used to modify domesticated species in useful ways. Nonetheless, GMOs are also a threat to biodiversity, as they can breed with wild species and could outcompete wild relatives. GMOs are controversial in other ways, including for their potential effect on human health and the ethical questions that are raised by significantly modifying the genetic makeup of species. 

While human activity drives species decline, the exact nature of that relationship is complex, and no one action is responsible for biodiversity loss. Conservation biologists refer to this multiplicity of factors with the acronym HIPPO: habitat destruction, invasive species, pollution, population, and overharvesting. In his discussion of biodiversity decline in Hawaii in Chapter 3, Wilson notes that population is the driver of the other factors, as more people on the planet augment the use of land and resources, but in terms of impact, the factors are listed in descending order, starting with habitat loss. Population is also important to this framework, because when there were fewer people on the planet, the order was reversed. With this lens, biologists have been able to understand species decline even when the immediate cause is not obvious, as was the case with the Vancouver Island marmot. Using HIPPO in that way, Wilson says, can also help develop strategies for how such a species might be saved. 

Megafauna are the largest animals, with weights of 10 kilograms or more. As humans moved across the planet thousands of years ago, their arrival was followed by the extinction of much of the megafauna in the areas in question. In contrast, microfauna are life forms such as microbes, fungi, and invertebrates, and it is to these that we must also look for biodiversity, Wilson says.