The case against the concept of biodiversity
In 2017, an evolutionary biologist named R. Alexander Pyron ignited controversy with a Washington Post commentary titled “We don’t need to save endangered species. Extinction is part of evolution.” He wrote: “Conserving a species we have helped to kill off, but on which we are not directly dependent, serves to discharge our own guilt, but little else.”
Pyron’s take challenged the decades-old idea that biodiversity is a good thing — that humans should strive to preserve all forms of life on Earth and their interconnectedness across ecosystems. It prompted scientist and writer Carl Safina to mount a passionate defense of biodiversity, calling Pyron’s stance “conceptually confused” and containing “jarring assertions.” Safina’s most cutting rebuke was that belittling biodiversity derails environmental conversations. “It’s like answering ‘Black lives matter’ with ‘All lives matter,’” he wrote. “It’s a way of intentionally missing the point.”
Nobel Prize winners co-signed more rebuttals. Professors blogged long meditations on why endangered species need to be saved. There were scientists who had previously questioned a hyperfocus on saving species, to be sure, though none had done so in such a public and broad-sweeping manner as Pyron. Josh Schimel, an ecologist at UC Santa Barbara, wrote: “Remember, you are a scientist — it is not your job to be right. It is your job to be thoughtful, careful, and analytical.” Pyron declined a request for comment for this story.
Ginger Allington, a landscape ecologist and professor at George Washington University who tracks the scientific debate around “biodiversity,” says this scientific back-and-forth reflects increasing conflict about the importance of biodiversity and species loss.
The most common way to measure biodiversity is to count the number of species in a certain place, also known as “species richness.” But critics question the usefulness of this number and argue that the concept has always been fuzzy, even to scientists, akin to a “new linguistic bottle for the wine of old ideas.”
A handful of scientists want to do away with the term biodiversity altogether — and have been trying to do so since the late 1990s. The concept, they say, is hard to quantify, hard to track globally over time, and actually isn’t an indication of what people commonly picture as a “healthy” ecosystem. (Scientists are generally reluctant to describe ecosystems in terms of “healthy” or “unhealthy,” which are value judgments.)
Last year, the United Nations reported that the world has failed to reach even one of the major biodiversity conservation targets it had set for itself in 2010. In the face of accelerating species and habitat loss, countries are now committing to protecting 30 percent of land and water by 2030. This fall, 193 nations are set to attend the virtual Convention on Biological Diversity to hash out a plan to stop biodiversity loss. (A draft of that plan was published last month.) In the US, the Biden administration has proposed its own game-changing approach to nature conservation. Meanwhile, a coronavirus pandemic that may have begun in animals reminds us that we are fundamentally linked to the animals in these critical habitats.
Against this backdrop, a new generation of scientists is taking up the debate about what to do about “biodiversity” itself — the scientific concept, its popular understanding, and indeed the very word. As Allington told Vox: “There’s just a lot of drama.”
The backstory of biodiversity
Before there was biodiversity, there was BioDiversity. A key moment in the evolution of the word came at the National Forum on BioDiversity, held at the Smithsonian Institution and National Academy of Sciences, in 1986. Speakers included Jared Diamond, who later authored Guns, Germs, and Steel, and the biologist E.O. Wilson, who most recently popularized the idea of protecting half the planet.
Diamond and Wilson — along with seven other white male scientists in attendance — dubbed themselves the “Club of Earth” and held a press conference, telling reporters that biodiversity loss was the second-biggest “threat to civilization.” The first? Thermonuclear war.
Few women scientists or non-Western experts were featured. And not everyone felt comfortable crowning biodiversity as a scientific silver bullet, for that matter. One news report from the time quoted biologist Dan Janzen, who said at the forum that “one shouldn’t use the number of species as the only criterion for earmarking an area for conservation.” Janzen would later call the forum “an explicit political event” and said that the word biodiversity got “punched into that system at that point [in time] deliberately.”
Still, the forum drew 14,000 in-person attendees. Another 10,000 watched a live “teleconference” of key panelists beamed around the world. “BioDiversity: The Videotape,” a campy VHS recording of the teleconference spliced with wildlife footage, sold out. The New York Times, Washington Post, Boston Globe, and Time all covered the event, marking “the first time that biological diversity … had received such a broad public airing,” a December 1986 article in the journal BioScience noted. The forum not only streamlined the term — thanks to a suggestion by biologist Walter Rosen — but brought the buzzword to the forefront, as the growing rate of global species extinctions was given both a name and an urgency. “The biodiversity crisis,” Wilson said at the forum, “is a real crisis.”
Against the odds, the idea of biodiversity spread outside of science and around the world. “I’d compare the market penetration of ‘biodiversity’ to Madonna,” said Stuart Pimm, a conservation biologist at Duke University.
Pimm witnessed the word’s use rise suddenly in the 1980s as a young associate professor. Before then, Pimm had no simple name for the kind of research he was doing — now called conservation biology — and, more problematically, no term for what he was measuring out in the field. And so biodiversity “hit several things simultaneously,” he said. “It’s easy to popularize, it captures people’s imagination, and it’s scientifically credible.”
Three ecologists shaped “biodiversity” into the kind of science that goes mainstream, according to Pimm. Thomas Lovejoy coined the term “biological diversity” in the 1980s. Elliott Norse defined it as the variety of genes, species, and ecosystems in a given area. And Wilson, who initially deemed the contraction biodiversity “too glitzy,” ultimately popularized the word. In 1992, the UN codified the word biodiversity — and Norse’s definition — into the Convention on Biological Diversity, a multilateral treaty.
Biodiversity was thus conceived to capture two notions: a world teeming with wildlife, and the political problem of stopping extinctions. The idea had become “a force” capable of influencing global society, as climate and environmental law expert David Takacs wrote in his 1996 book The Idea of Biodiversity. “It is difficult to distinguish biodiversity, a socially constructed idea, from biodiversity, some concrete phenomena,” Takacs wrote.
But over the years, biodiversity has come to mean many things to different people — from “local species” to “wildness” to “natural balance” to just “a fancy word for nature,” according to a study of public opinion in Scotland. Researcher R.A. Lautenschlager, in a 1997 scientific article titled “Biodiversity is dead,” put it more bluntly: “Biodiversity has become so all-inclusive that it has become meaningless.”
“We need to be careful about what we are saying”
A practical question flows from this history: Does saving every species still matter?
Allington has seen colleagues try to address this kind of question publicly, and their answers, she says, tend to get misinterpreted. “We need to be careful about what we are saying,” she said.
To unpack this question in her college courses, Allington — who considers biodiversity to be “multifaceted” — passes out bags of mixed candy to her students, illustrating a key point: “The bags show that not all species play the same role in the ecosystem,” she said. Some species, like oysters, make key contributions to the ecosystem, and their disappearance would threaten all the rest. “The problem is that we still don’t know what functions the majority of species actually provide,” she said.
Scientists in today’s save-all-species debate disagree about where the science ends, and where the subjective idea of right and wrong begins. In this sense, debates about biodiversity may ultimately be debates about ethics, implicit human values, and whose ecological knowledge matters.
“Does every species matter?” asked Mark Vellend, a plant ecologist at University of Sherbrooke in Canada. “You cannot even give an answer unless you say, matter for what?”
How to measure “goodness”
The late biologist Michael Soulé, the “father of conservation biology,” was unequivocal that biodiversity is good — though its goodness, he wrote, “cannot be tested or proven.”
But in specific places, biodiversity for biodiversity’s sake is not necessarily good. On islands, for example, plant diversity is generally increasing because non-native species are arriving; some rare island plant species may go extinct as a result, but not always. Biodiversity might also be the wrong lens in ecosystems that weren’t diverse to begin with, like boreal forests close to the Arctic, which have low numbers of species that rarely face extinction even in the face of logging.
Many scientists recognize biodiversity as an imperfect yardstick. The total number of species, and how it changes, doesn’t capture all the ways that humans and other forces alter landscapes. “‘More biodiversity’ is not a universal prescription for conservation,” journalist Michelle Nijhuis writes in Beloved Beasts, a history of the conservation movement.
It also doesn’t capture the human experience of nature. A 2013 study — “Is biodiversity attractive?” — found that when it comes to outdoor recreation, visitors don’t actually prefer species-rich urban spaces. “Especially during the pandemic people [are] flocking to natural, wild spaces,” said Vellend. “Whether in those spaces there are 1,000 species or 100, to me that’s a pretty small part of the overall story.”
For many people, the on-ramp to nature is not through science. “Their point of entry is aesthetic,” Barry Lopez, the nature writer and Arctic Dreams author, said in a 2001 interview. “It’s not that they don’t know what biodiversity is, but it doesn’t have the pull,” he added. “The door for them lies elsewhere.”
A more measurable dimension of a place’s “goodness” within the human story, some scientists think, is ecosystem function. Forget the number of species, in other words, and focus on what each does for keeping an ecosystem enjoyable and humming, like the life-supporting role of oak trees — which support hundreds of species of caterpillars, a mainstay in most songbird diets — in North American hardwood forests. Using this framework, land managers would focus their conservation efforts on species that appear to play the most crucial role in a given ecosystem. (An 80-page US National Park Service report, called “Resist-Accept-Direct,” recently called for this triage approach.)
Pimm, for his part, thinks this framework is “total bullshit” — and he is not alone in that sentiment. It’s hard to develop a conservation plan around the emerging concept of ecosystem function, according to Pimm, precisely because we still know so little about the role of any given species in a place. “What does one even mean by ecosystem function?” he asked. “It doesn’t have any operational meaning.”
The concept of biodiversity is becoming even more influential in the realm of climate policy: In June, the Intergovernmental Panel on Climate Change published its first-ever joint report with the Intergovernmental Platform on Biodiversity and Ecosystem Services. Yet one of its authors, the Paris-Saclay University ecologist Paul Leadley, said while introducing the report that current on-the-ground approaches to saving species are essentially outdated. “We have to really rethink biodiversity conservation,” he said.
There is a broader movement to expand the meaning of “biodiversity”
So if the idea that saving every species saves the planet is imperfect, should we now abandon biodiversity?
“A concept can’t truly die until it’s got a replacement,” said Vellend. He says that the 1980s version of biodiversity should be seen as a starting point, with plenty of room for improvement. “Until somebody comes up with something better, we’re stuck with it.”
Even R. Alexander Pyron, the author of the explosive Post piece, cautioned against dropping “biodiversity” in a mea culpa he posted on his Facebook page after blowback from his peers. “I succumbed to a temptation to sensationalize parts of my argument,” Pyron wrote.
But others see an opportunity to expand the notion of biodiversity into something more inclusive and more just. Campaigns like #BiodiversityRevisited have created virtual dialogues and in-person workshops where an array of voices discuss ways of breathing new life into “biodiversity.” These discussions have pushed out possible replacement terms, like “fabric of life,” that might better capture the full range of life on Earth, from thriving trees to prospering pandas to healthy people.
One starting point might be to broaden the biodiversity concept to include humans, breaking down the barrier between our species and other animals. “My well-educated scientist colleagues will often slip and say ‘mammals and humans.’ Every time, I get a chill down my spine,” said Hopi Hoekstra, an evolutionary biologist and curator at Harvard University’s Museum of Comparative Zoology. Humans are mammals, after all. That even experts make these slips of the tongue “just highlights that there is still something to overcome there,” Hoekstra said.
Conservationists could also gain from a broadened notion of biodiversity that centers Indigenous and traditional knowledge, which has long been diminished by establishment science. Research shows that lands managed by Indigenous people are home to much of the world’s biodiversity, and that biodiversity tends to decline more slowly on those lands.
“Many of these Westernized concepts, we don’t see ourselves in them,” Andrea Reid, a fisheries scientist at University of British Columbia and a citizen of the Nisga’a nation, said. Indigenous concepts of conservation “include people within the system,” said Reid, who monitors diversity in British Columbia’s coldwater streams by counting species in ways that have cultural meaning to Indigenous people.
Reid has been working with Indigenous “knowledge keepers” who will go to a stream and look for certain species of dragonfly — for them, a “cultural indicator” that marks a healthy ecosystem. Other scientists might go to the same place and tally all insect species to measure local species richness. These measures can be used together, Reid says, to assess the overall condition of the stream over time.
This kind of “pluralistic” perspective, as some scientists call it, aligns with what Reid calls “two-eyed seeing” — a way of bringing together Indigenous and Western understandings. “It’s not about throwing something out, or just walking away from ‘biodiversity’ and its metrics,” Reid said. “It’s about enriching our understanding by bringing multiple perspectives to bear.”
