Discover 1-2

34 DISCOVERMAGAZINE.COM

CLOCKWISE FROM TOP: JOHANNES KRAUSE, MAX PLANCK INSTITUTE FOR EVOLUTIONARY ANTHROPOLOGY; RICHARD G. ROBERTS; SYLVIO TÜPKE, MAX

PLANCK INSTITUTE FOR EVOLUTIONARY ANTHROPOLOGY; GROUP OF PALEOANTHROPOLOGY MNCN-CSIC

26

Sifting Soil for

Human Ancestors

❯

SCIENTISTS HAVE FOUND

ancient human DNA in

caves, no bones or teeth

required. Instead, an international

team located genetic traces of

Neanderthals and Denisovans —

both distant hominin cousins of

ours who died off about 40,000

years ago — just from dirt.

Researchers have been able to

identify animal and plant DNA

from soil samples since 2003,

but this is the first time they’ve

extracted hominin DNA.

It was no easy feat. The group

scooped soil samples from seven

European and Russian caves

known to have housed prehistoric

peoples. Using the latest DNA

filtering techniques, researchers

sifted through trillions of genetic

fragments from plants, other

mammals and modern humans

to pinpoint the ancient hominin

sequences. While they found

Neanderthal genetic traces at

several of the sites, Denisovan

DNA turned up only in a

Siberian cave.

The work, published in Science

in April, opens up new possibilities

for researchers, says Viviane

Slon, a geneticist at the Max

Planck Institute for Evolutionary

Anthropology in Leipzig,

Germany, and a co-author of the

study. Now, she says, they could

unearth evidence of prehistoric

occupation at sites where no

human fossils or tools have been

found, expanding our knowledge

of hominin history. — MARK BARNA

Viviane Slon (left), a co-author

of the work, prepares a

soil sample (such as the one

above) for DNA extraction.

Caves like these in Croatia (top) and

Russia (above) housed the soil that

researchers used to find genetic traces

of our ancient ancestors.