18 | New Scientist | 4 July 2020
SpaceDogs were
bred to pull
our sleds
millennia ago
THE 9500-year-old remains of
a dog found on a remote island
off Siberia are remarkably similar
to living sled dogs in Greenland,
genome sequencing has revealed.
The discovery shows that people
bred dogs for pulling sleds more
than 10,000 years ago.
“We thought it would be a
primitive dog, but it’s a long way
down the path to domestication,”
says Mikkel Sinding at the University
of Copenhagen, Denmark. “That
was quite sensational.”
Excavations of ancient human
settlements on Zhokhov Island
north of Siberia have revealed
the remains of numerous dogs
and what look like dog sleds. “It’s
the first place in history where youClimate change Zoology^Nearby exoplanet
may be ideal for life
JUST 11 light years away from
Earth, two hot, rocky worlds
orbit a small, red star. Their
relative proximity makes them a
promising study target, and there
may be a third, habitable planet.
Sandra Jeffers at the University
of Göttingen in Germany and
her colleagues caught sight of
the planets orbiting red dwarf
star GJ 887 by watching for the
wobbles in its light caused by
the planets’ gravitational pull.
These indicated that there
were two hot planets circling close
in to the star and suggested there
might be a third orbiting further
out (Science, doi.org/d2hj).
The third world, if it exists, could
be within the star’s habitable zone:
the area where water on the
surface of the planet could remain
liquid instead of freezing or
boiling away. Leah CraneHotter forecast could
be due to cloudsNEW computer models have
begun projecting a potentially
much hotter future as carbon
dioxide levels rise, and the reason
seems to be to do with clouds.
The latest climate models show
a much wider range for the future
temperature than earlier ones,
up from between 1.5°C and 4.5°C
to between 1.8°C and 5.6°C. The
estimates are for when the climate
system comes into equilibrium
after CO 2 levels have doubled.
The results imply that climate
sensitivity – how much the planet
will warm based on a given
increase in CO 2 – is higher than
previously thought. More realistic
representation of clouds and
aerosols seems to be the likely
reason, according to Gerald Meehl
at the US National Center for
Atmospheric Research and his
colleagues, who looked at 37 of
the new models. Adam Vaughanhave intense dog use,” says Sinding.
His team sequenced the
best-preserved dog found
on Zhokhov, along with a
33,000-year-old Siberian wolf and
10 living sled dogs from different
places in Greenland, and compared
their genomes with each other and
with other dog and wolf genomes.
The results show that modern
sled dogs in Greenland, whose
ancestors were taken there by
Inuit people around 850 years ago,
are more closely related to the
9500-year-old Zhokhov dog than
to other kinds of dogs or to wolves
(Science, doi.org/d2g6).
“It’s largely the same dogs doing
the same thing,” says Sinding.
While the Zhokhov finds are
the earliest clear evidence of dogs
pulling sleds, ivory artefacts that
may have been used to attach reins
to sleds have been found elsewhere.
Some are 12,000 years old.
The genomes also show that
sled dogs haven’t acquired any DNA
from wolves in the past 9500 years.
Michael Le PageMAGDAL
EN
A^ LORDACH
E/COVER
IM
AGESNews In brief
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who had an average
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Reports, doi.org/d2gp).CHRISTOPHER
FURL
ONG/GET
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IMAG
ESReally brief