50 YEARS AGO
Mysterious red-coated canids in Texas are
stirring debate over how genetic diversity
should be preserved.
“I thought they were some strange-looking coyotes,” wildlife biologist Ron
Wooten says of the canids on Galveston
Island, where Wooten works. But DNA
evidence suggests the large canids might
be descendants of red wolves, a species
declared in 1980 to be extinct in the wild.
A small red wolf population from a captive breeding program lives in a North
UPDATE: Candidates for heart
or other organ transplants still
far outnumber donors. Every
day, 20 people on average die
while waiting for a transplant
in the United States. Scientists
hope to remedy the shortage
using organs harvested from
animals. To keep a human body
from rejecting nonhuman cells,
scientists are turning to gene
editing (SN: 10/14/17, p. 26).
So far, baboons given genetically modified pig hearts have
survived for about six months
(SN Online: 12/5/18). Others
are growing organs, creating
a sterilized scaffold from an
animal or cadaver organ and
repopulating the scaffold with
the organ recipient’s cells
(SN: 5/18/13, p. 14). Pigs have
survived several weeks after
being implanted with lab-grown lungs (SN: 9/15/18, p. 8).
Excerpt from the
March 15, 1969
issue of Science News
THE SCIENCE LIFE
Extinct red wolf genes
live on in coyotes
Both laymen and surgeons
have become faint-hearted
about heart transplants.…
The rejection and infection
problems remain unsolved,
and although Dr. [Denton
A.] Cooley has performed
the greatest number of
transplants in the world, he
has had to stop operating for
lack of donors.
Carolina conservation area. But those
wolves have had no contact with other
canids, including those in Texas. So
maybe, Wooten thought, red wolves never
actually went extinct in the wild. “There
was no way I could let this go,” he says.
He contacted evolutionary geneticist
Bridgett vonHoldt of Princeton University.
She and colleagues have amassed genetic
data on about 2,000 North American
canids, mostly coyotes and wolves.
VonHoldt often receives photos of wolflike animals, along with requests to identify
what species they belong to — an exercise
she describes as “challenging, and possibly
misleading.” Instead, she asks for tissue
Test fabric becomes more breathable as you sweat
Someday, the same shirt could be part of your summer and winter wardrobes,
using fabric that alternates between being breathable and insulating.
Unlike other heat-accommodating cloth, which has to be flipped inside out to
switch from warm to cool (SN: 2/17/18, p. 5), a new dual-use fabric adapts to how
much the wearer is sweating. The material could make for better sportswear or be
used in clothing for babies, who can’t articulate when they’re too hot or too cold.
The fabric, described in the Feb. 8 Science, is knitted from yarn composed of
many polymer fibers coated in carbon nanotubes. The closer these nanotubes are
together, the better the fabric conducts a person’s body heat as infrared radiation.
Under cool, dry conditions, the fibers
become loosely wound, and the fabric
traps much of the heat radiating off a
person’s body. But if the wearer sweats,
that humidity causes the polymer fibers
to constrict into tight bundles. This brings
carbon nanotubes on neighboring fibers
closer together, improving conductivity
and opening spaces to boost breathability.
Raising the humidity around the fabric
increases the amount of heat that passes
through it by up to about 35 percent, the
study finds. — Maria Temming
When it’s cool and dry, fibers inside a
new type of fabric are loose (as seen in
the fluorescent microscopy image, left)
and trap heat. When hotter, the fibers
constrict (right), allowing heat to escape.
Some canids on Galveston Island in Texas
carry DNA from red wolves, thought to be
extinct in the wild for almost 40 years. This
family group was photographed in 2013.