18 | New Scientist | 15 February 2020BiodiversityAtmosphere flows
wrong way on PlutoPLUTO’S tenuous atmosphere is
an oddity that spins backwards
thanks to a giant patch of ice on
the frigid world.
Key to this behaviour is an
enormous, bright heart-shaped
feature on the surface (pictured).
This was spotted when NASA’s
New Horizons spacecraft flew
past the dwarf planet in 2015.
One lobe of the heart is a deep
basin called Sputnik Planitia,Thousands more
viruses discoveredMORE than 2500 new viruses
have been found by scanning
mystery DNA recovered from
human and animal tissues.
The latest discoveries come on
the back of a search of human and
animal cells for genetic material
from the papillomavirus and
polyomavirus groups, which
exists as circular DNA, led by
Chris Buck at the National Cancer
Institute in Bethesda, Maryland.
While this search was a success,
it also threw up lots of circular
DNA sequences that didn’t fit
either of those groups or that of
other recorded viruses. So Buck’s
colleague Michael Tisza devised
a set of computer programs that
could sort through this surplus
data to look for new species.
This analysis of the mystery
DNA revealed 2514 new viruses.
While many belong to existing
families of viruses, 609 don’tMicrobiology^ Solar systemCLIMATE change has significantly
raised the risk of bumblebees being
wiped out in some areas of North
America and Europe.
Research five years ago showed
how warming had shrunk the bees’
habitat across the two regions.
However, it is difficult to separate
the direct effects of climate change
on the bees’ chance of suffering
a local extinction from other
environmental pressures.
To address this, Tim Newbold at
University College London and his
colleagues analysed temperature
and rainfall records at more than
15,000 sites where at least one
of 66 bumblebee species had been
spotted between 2000 and 2014.
They found that due to
changes in climatic conditions, the
probability of a site being occupied
by bumblebees fell by an averageof 46 per cent in North America and
17 per cent in Europe, relative to
the long-term average last century.
The results were as Newbold
expected. Bumblebees are large
and furry as an adaptation to cold,
so those in southern Europe and the
south of North America, which were
already at their upper temperature
limits, were more likely to go
extinct and less likely to colonise
a new area (Science, doi.org/dk78).
Losing bumblebees means
losing pollinators essential to food
production. Although they don’t
pollinate the crops we rely on for
most of our calories, they enable a
lot of our dietary variety, pollinating
plants that provide nuts, berries
and squashes. If climate change
continues, it will drive even stronger
bumblebee declines in the future,
says Newbold. Adam VaughanGlobal warming raises risk
of bumblebee extinctions
which is filled with nitrogen ice.
When the sun rises over Sputnik
Planitia, some of the ice turns into
gas, floating into the atmosphere.
At night, it cools and settles back
into the basin as ice again. Tanguy
Bertrand at NASA’s Ames Research
Center in California and his
colleagues used a weather forecast
simulation to determine how this
cycle would affect the circulation
of Pluto’s atmosphere.
They found it causes nitrogen
winds that blow westward. They
are strongest at the western edge
of Sputnik Planitia, where they
appear to create dark streaks
as they rush out of the basin.
These winds cause the
atmosphere to rotate in the
opposite direction to Pluto,
which spins towards the east. This
behaviour is surprisingly different
from the other atmospheres we
know of, says Bertrand, as this
hasn’t been confirmed to happen
anywhere else in the solar system
(Journal of Geophysical Research:
Planets, doi.org/dk8d). Leah Craneresemble any known ones (eLife,
doi.org/dk77). Some of the new
examples are highly unusual. One
belonged to a group called CRESS
viruses, but was far bigger than
any known CRESS virus.
It is possible some of the new
species may be dangerous. For
instance, the team found more
than 100 anelloviruses in human
blood. As yet, no anellovirus has
been linked to a human disease,
but conceivably some of the new
ones could be harmful. “The first
step in finding out whether a virus
is causing a disease is finding out
the virus exists,” says Buck.
Tisza has now developed a
more advanced version of the
software that can identify other
kinds of virus that lack circular
DNA. In unpublished work, he
has applied it to the genetic data
sets of other research groups.
“There’s 20 petabytes of data,”
says Buck. “Those data sets have
already yielded 75,000 new virus
species”, some of which are “very
exotic”. Michael MarshallED RESCHKE/GETTY
NASA/JOHNS HOPKINS UNIVERSITY/APLNews In brief