34 | New Scientist | 30 January 2021
The other
humans
A mysterious prehistoric people once known only
from DNA they left behind are now emerging
from the shadows, finds Michael Marshall
T
ODAY, there is only one species of
human alive on the planet. But it
wasn’t always so. For millions of years,
and until surprisingly recently, there were
many types of human-like groups, or
“hominins”. They coexisted, perhaps they
fought, and they interbred. It would be
fascinating to know how these others lived,
but understanding who they were and what
they were like is extremely challenging.
We cannot put ourselves into their minds,
and we have only fragmentary clues from
fossils and artefacts they left behind to
reconstruct their lives.
That challenge is especially daunting for
one of these extinct groups, the Denisovans.
Discovered just a decade ago, the Denisovans
have left us scant physical evidence.
Instead, our knowledge of them comes
almost entirely from their preserved DNA.
It tells us that they are a sister group to the
Neanderthals, that they lived in Asia for
hundreds of thousands of years and that
they interbred with our species. But we
don’t know what they looked like, how
they walked or if they could speak.
Now, that is changing. In the past few years,
archaeologists have alighted on a few fossils
that seem to be Denisovan. They have also
unearthed treasure troves of artefacts,including tools, jewellery and even art, that
they think were created by these mysterious
people. These interpretations are potentially
explosive, so it is hardly surprising that some
dispute them. Nevertheless, we are starting
to piece together a picture of the Denisovans,
one of our closest cousins, and a group that
still lives on in the DNA of many people today.
The discovery of the Denisovans came as
a total surprise, partly because it played out
differently from the uncovering of every
other extinct human group. The story starts
in the Altai mountains in southern Siberia,
Russia. For decades, archaeologists have been
excavating in Denisova cave – named after
a hermit called Denis who lived there in the
18th century. Hominins have inhabited it on
and off for hundreds of thousands of years.
Most were Neanderthals who, although
most prevalent in Europe and west Asia,
sometimes made it as far east as the Altai.
In 2008, archaeologists led by Michael
Shunkov at the Russian Academy of Sciences
in Novosibirsk discovered a fragment of
finger bone in the cave. Assuming it belonged
to a Neanderthal, Shunkov sent it to Svante
Pääbo at the Max Planck Institute for
Evolutionary Anthropology in Leipzig,
Germany. Pääbo’s team extracted DNA
from the bone and found it didn’t match > BRIANSTAUFFERFeatures Cover story