If life on Earth is like a vast library – one book per species – Paul Hebert's dream is to catalogue that library and reveal, for the first time, the full scope of the richness that it contains.
His nightmare is that we are burning the books without even bothering to read them.
"One third of the living species on our planet could be gone by the end of this century," said Prof. Hebert, who heads the Biodiversity Institute of Ontario at the University of Guelph.
"We will regret it a very long time in the future if we don't do something."
By "something" Prof. Hebert means a project of unprecedented scale, a biological moonshot in which Canada would play a leading role.
The time has come, he says, to genetically index every multicellular species on Earth – estimated to number somewhere between 10 and 20 million – before a large share of those species vanish without a trace.
"Obviously we recognize this is a giant challenge when you start thinking about it," Prof. Hebert said.
"But this is not science that can wait."
A version of the project is already under way, thanks to a technique that Prof. Hebert has long championed.
Known as DNA barcoding, it involves using a small set of genetic markers to uniquely identify any species that biologists can sample, like a product barcode at a supermarket checkout.
The method forms the basis for the International Barcode of Life, a $100-million initiative that was launched in 2010 and is supported by Canada, Germany, China and the U.S. National Science Foundation among other partners.
Now in its final year, the project is nearing its goal of barcoding 500,000 species, an achievement that will be celebrated at a scientific meeting in Guelph next week.
But for Prof. Hebert the most important outcome of the effort is that it demonstrates that DNA barcoding can work at even large scales. During the meeting he plans to unveil his ambitious proposal for a $2.5-billion expansion of the concept to barcode all species of plants, animals and fungi both on land and in the oceans.
Tom Lovejoy, a conservation biologist at George Mason University and a senior fellow at the United Nations Foundation in Washington, D.C., is among the prominent scientists coming to voice support for the plan.
"Aldo Leopold [the pioneering American ecologist] said that the first rule of intelligent tinkering is to save all the pieces," Prof. Lovejoy said. "Barcoding tells you what the pieces are."
It was Prof. Lovejoy who first coined the term biological diversity in 1980 to express what scientists were beginning to understand as a more systematic way of looking at life on Earth. Now the tools of the genetic revolution have handed scientists a way to quantify that diversity, which many experts say is a necessary prerequisite for preserving and managing it.
"Otherwise we're just fumbling in the dark," said Prof. Lovejoy.
The cost of Prof. Hebert's supersized barcoding project would have to be borne by a coalition of nations, like other big science initiatives including the Large Hadron Collider or the Thirty Metre Telescope.
But Canada, where the idea originated and where the International Barcode of Life database is housed, would be in a position to spearhead the effort, potentially making it one of this country's most significant contributions to the world in any domain.
"More than any other country, Canada has invested in the research and infrastructure which is now used globally," said Jan van Tol, managing director of the Naturalis Biodiversity Center in Leiden, the Netherlands.
The new proposal would turn DNA barcoding into a megascience, a major leap for a technique that has sometimes met with resistance from other researchers.
In part this is because those who practice taxonomy, a science that defines organisms on the basis of their physical characteristics, had to be convinced that the genetic differences used in barcoding truly correspond to distinct species. For example, the method has been harder to apply to plants than animals, because plant genetics are a more complicated affair.
Nevertheless, barcoding has the advantage of using genetics to discern species-level differences among large numbers of individuals even when those differences are not visually apparent.
Prof. Hebert has demonstrated this by setting up a trap for insects in his backyard. Instead of trying to identify the countless individual bugs it captured – a practical impossibility – he ran the trap's contents through a blender and genetically tested the result. Barcoding quickly told him that some 5,000 different arthropod species inhabit his backyard, a number he said he found "staggering."
This type of approach reveals that certain sections of the insect class are unaccountably diverse, notably wasps and ants and some types of flies and beetles. What they all have in common is that they are haplodiploid – meaning that males of the species develop from unfertilized eggs and have only one copy of each chromosome rather than the standard two. Barcoding suggests that this unusual breeding system somehow accelerates the rate of evolution.
More broadly, the method brings the definition of a species closer to what it really is: A slice through a continuum of shifting and diverging genetic combinations rather that an immutable item on a long list of birds and beasts.
"Barcoding allows us to notice two species that are far earlier in their evolutionary splitting … to the point where they can still exchange genes," said Dan Janzen, an evolutionary ecologist at the University of Pennsylvania, responding from a field station in Costa Rica. "I now see that I live in an ocean of emerging species."
Scientific insights aside, DNA barcoding has social and economic implications because it can be deployed to help halt the loss of biodiversity, one of the sustainable development goals expected to be adopted by the United Nations next month, Prof. Lovejoy said.
Prof. Hebert said he wanted his proposal to be seen as more than a research exercise.
"We're going to pitch this project as humanity's need to know."