30 January 2021 | New Scientist | 35Where did the
Denisovans
come from
and where
did they go?
Genetically, the Denisovans are a
sister group to the Neanderthals.
The two diverged about 400,000
years ago from a shared ancestor,
one that had previously split from
the line that led to our species
around 600,000 years ago. It isn’t
clear why the Denisovans and
Neanderthals diverged, but a new
idea suggests that as the Arctic ice
sheet expanded southwards to the
Black Sea, cutting Europe off from
Asia, it divided the early humans
into two populations, which
became Neanderthals in the west
and Denisovans in the east.
There is little evidence to indicate
when and why the Denisovans died
out. The most recent interbreeding
episode with Homo sapiens^ may
have been just 30,000 years ago.
It is possible that there was so
much interbreeding that
Denisovans faded into the wider
early human population.
Alternatively, on arriving in
Denisovan habitat, H. sapiens may
have outcompeted or killed their
cousins, or brought lethal diseases.
Climatic events could have been
crucial too. “If we accept
Denisovans lived from Siberia to
Indonesia, you have very different
climatic and environmental
circumstances in which they lived,”
says Bence Viola at the University
of Toronto, Canada. “So I feel that
there likely is not a single answer.”