January/February 2019^ DISCOVER^47
CLOCKWISE FROM TOP: M. FISHER ET AL./ECOLOGY AND EVOLUTION/MARCH 4, 2018 CC BY 4.0; A. VAN DEYNZE ET AL/PLOS BIOLOGY/AUGUST 7, 2018 CC BY 4.0; RON COHN, PH.D./THE GORILLA FOUNDATION/KOKO.ORG
Koko:
In Memoriam
For more than four
decades, Koko the gorilla
and her American Sign
Language (ASL) skills
captured the public’s
attention. Born in 1971 at
the San Francisco Zoo, the
western lowland gorilla
began learning ASL the
following year from Penny
Patterson, then a graduate
student in psychology.
Koko, shown here holding
All Ball, a kitten she named
herself, raised awareness
of her critically endangered
species through frequent
media appearances, and
reshaped attitudes about
animal intelligence. She
died in her sleep on
June 19, at age 46.Nitro Corn to the
(Potential) Rescue!
For decades, scientists have tried to
coax corn to create its own fertilizer.
A team of researchers has found one
corn variety, in the southern
Mexican state of Oaxaca,
that’s been producing
its own fertilizer all
along. The discovery,
published in PLOS
Biology in August,
could transform how
the crop is produced
worldwide.
Commercial plant
fertilizers typically
include nitrogen, which
helps grow healthy crops but
also causes environmental damage.
This Oaxacan corn variety develops
prominent, fingerlike aerial roots that
secrete a carbohydrate-rich goo. The
mucilage supports bacteria that convert
atmospheric nitrogen into a form the
plant can use. If the trait can be bred
into other crop varieties, it could mean
less nitrogen from artificial fertilizers in
the environment — and big cost savings
for growers. Researchers are exploring
the possibility.FURTHER AFIELD
Where Are the Wild Things?
Every year, researchers turn up
insects and plants new to science,
but finding new mammals
doesn’t happen that often. Don’t
assume it’s because we’ve found
them all, however.
A University of Georgia team
created a mathematical model
to predict the total number of
mammals living today based on
a variety of known biodiversity
parameters, according to a paper
published in March in Ecology and
Evolution. Their results suggest
that biologists have found only
95 percent of them.
With the current count of knownliving mammal species at about
6,400, that means at least 300 more
species are still out there.
Knowing where to look is key,
says Molly Fisher, an ecologist and
lead author of the March paper. Her
research suggests that sub-Saharan
Africa, Eurasia and South America
will be hotspots for finding more
mammals.
“We are currently in a major
extinction event,” says Fisher, “and
we must know as much as possible
about the current biodiversity of
the Earth in order to understand
the world that we are living in and
how it is changing.”Warmer colors:
hotspots for finding
new mammals