Popular_Science_2020_Winter bookshq.net

HIGH ALTITUDE
Thousands of feet
above sea level, thin
air triggers the body
to boost oxygen-rich
red blood cell pro-
duction. This helps
us breathe until de-
scent, but after too
long turns blood vis-
cous enough to clot.
Tibetans and some
Ethiopians, who live
at up to 14,000 feet,
have a gene that
stops the surge to
keep clots at bay.

Dry air traps less

heat, causing daily

temperature shifts

from scorching hot

nights. Aboriginal

Australians have

genes associated

with temperature-

ers are still studying

them, but we think

the genes help the

arid dwellers thrive

in both extremes.

EXTREME COLD
In coastal glacial cli-
mates with subzero
temperatures, food is
limited to blubbery
fare like seals, wal-
ruses, and whales.
High-fat diets typi-
cally raise the risk of
heart disease and
cancer, but some lo-
cals like Greenland’s
Inuit have evolved
genes that help them
process the suste-
nance without any of
the downsides.

DEEP WATERS

The Bajau people of

Southeast Asia

plunge up to 200 feet

to catch fish. Their

secret is the huge

size of their spleens.

blood cells and

release a boost of

oxy gen when we dive;

a gene variant that

tweaks hormones re-

sponsible for spleen

size means the Bajau

people can tap a

bigger reservoir.

WINTER 2020/ POPSCI.COM

no place like home

as told to Marion Renault

People have inhabited some gnarly landscapes
throughout history. Innovations like fire and
clothing have helped us conquer these inhospitable
places, but so has our DNA. With the aid of technolo-
gies like genome sequencing, scientists are unraveling
how humans endure all kinds of treacherous conditions.
Here are four adaptations that show we can turn an
locale—hot, cold, wet, dry—into a humble abode.

119

MELISSA ILARDO,
POSTDOCTORAL RESEARCH FELLOW
AT THE UNIVERSITY OF UTAH’S
MOLECULAR MEDICINE PROGRAM

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