How Many Species can We Afford to Lose?

UBC Reports | Vol. 49 | No. 12 | Dec.
4, 2003

How Many Species can We Afford to Lose?

Researchers use new approach

By Michelle Cook

Will we really be worse off when the last giant panda disappears
from the earth? Does our own survival depend on the fate of
the mountain gorilla? The whooping crane? The common house

The popular answer to all these questions would be ‘yes.’
The fact is we just don’t know, says UBC zoology professor
Anthony Sinclair, who has launched a project to study what
really happens when a species gets “knocked out”
of one of the planet’s ecosystems.

“One of the dogmas that our society has is that biodiversity
plays an important role in the stability of our systems, but
we haven’t actually got the evidence yet to support
this,” says Sinclair. “It sounds nice. It sounds
logical, but my own experience of seeing so many species is
that they can’t all have equally important roles. There
must be a huge number which don’t matter.

“We need to ask, ‘does it matter?’ and
it’s important to recognize that we don’t know
the answer.”

With a worldwide environmental movement fighting to protect
thousands of plants, animals, insects and birds on endangered
species lists, Sinclair knows it’s a loaded question
but one he will keep asking with the Biodiversity Knockout
Experiment (BIOKO).

Launched two years ago with a pilot project in the Yukon,
the BIOKO’s goal is to find out how the loss of a certain
species from an ecosystem affects the system’s ability
to cope.

“We want to find out whether losing a species prevents
the system from coping with the abuses humans subject the
system to — abuses such as introducing fertilizers, burning,
trampling, and polluting it,” Sinclair explains.

“It’s a fundamental problem of human society.
It’s inevitable that, as we develop, we’re taking
up more resources in the world which will cause more species
to go extinct. The question is how many species can we afford
to lose before we impair the habitat that we live in and depend

After spending almost 40 years studying large mammals, mostly
on the Serengeti Plain in his native Tanzania, Sinclair has
seen the effect one species can have on an entire ecosystem.
Fifty years ago, disease had reduced the population of wildebeests
on the plain to 100,000. Today, they number 1.5 million. With
their comeback, Sinclair and others have been able to track
the effect on thousands of other species of plants, insects
and animals and also on the climate in the wildebeest’s
habitat. But nobody has ever tried a controlled knock-out

For the BIOKO experiment, researchers will first remove a
key species group from a controlled study plot. They will
then subject the plot to a man-made disturbance. In the Yukon
pilot being undertaken by UBC botany professor Roy Turkington
and student Jennie McLaren, groups of native plants, legumes
and fungi have been removed from the study area and fertilizer
has been applied. The effects of the species loss on the plot
will be monitored over three years.

It’s an approach that’s never been tried before.
In the past, researchers have studied biodiversity by putting
a few species together in a controlled environment, and extrapolating
the results to determine the effects on larger habitats. The
knock-out experiment starts at the opposite end of the scale
with thousands of species and systematically removes key groups.
If the Yukon pilot is successful, plans are underway to conduct
the same experiment in many different geographical environments
such as grasslands, savannah and tundra. Sinclair says that
Canada, with its extreme environments ranging from the Far
North with no species to the Prairies with a diversity of
species, is particularly suited to the BIOKO experiment.

The massive, worldwide initiative will be run from UBC’s
Integrated Biodiversity Laboratory, a new facility for multidisciplinary
research that will be built with $33 million in funding from
the Canada Foundation for Innovation and the B.C. Knowledge
Development Fund, in addition to funding from UBC.

Once the lab is completed, in about five years, Sinclair
expects BIOKO to swing into high gear, with a new generation
of ecosystem specialists from around the world involved in
knock-out research.

“This is a big idea, and a big experiment; it will
take a lot of people, and we can’t do it all at once,”
Sinclair explains. “So this is going to be done bit
by bit and when we get different people trying different things,
we’ll learn from that to build a more comprehensive

And if animal lovers were getting nervous, rest assured there
are no plans to knock out any of the big predators or beloved
furry poster animals — elephants, otters, orangutans — that
we’ve come to associate with habitat loss or extinction.

Researchers will be focusing instead on insects, plants,
fungi and species like the nematode — a hard working little
organism that lives in the soil decomposing dead plant material
and recycling nutrients from it — because that’s where
they suspect most of the real biodiversity action is.

“If you knock out mammals, at a certain scale, it doesn’t
matter,” Sinclair says. “In terms of the way the
world functions, it probably doesn’t matter whether
we’ve got pandas or not. They’re nice and furry,
appeal to us emotionally and esthetically, and could act as
flagships to promote conservation, but in terms of how the
system works, it’s probably not a big deal.

“Whereas, if you knock out certain bacteria from the
soil, it’s a big deal. We don’t know that — yet,
but there’s an old adage that the answer lies in the
soil and it probably does.”

For this reason, the project may not capture the public’s
imagination and attention the way the studies of specific
species done by scientists like Diane Fossey and Jane Goodall
did 40 years ago, but Sinclair says the issues that BIOKO
will be addressing are very much on the 21st century agenda.