34 | New Scientist | 4 April 2019

and modern genomes are tearing apart

that neat tale. The Jebel Irhoud skull has

turned out to be a key to a new, slowly

emerging paradigm. With the dust yet

fully to settle, the question now is how

many, if any, of our old assumptions

still hold. “Should we be thinking of

a completely different model?” asks

Foley. “Abandoning out-of-Africa?”

Strap in, it’s going to be quite a ride.

The out-of-Africa paradigm to which

Foley refers has become so entrenched

that it is easy to forget how new it is.

For decades before its emergence,

human origins research was dominated

by the early characters in the story:

Homo erectus, for example, including

“Peking Man”, unearthed in 1929; or

Australopithecus afarensis, the famous

“Lucy” discovered in Ethiopia in 1974.

There was some debate about where

modern humans appeared, and ideas

were floating around of a recent

African origin, but the fossil record

seemed to support a model called

multiregionalism. This argued that

archaic humans were distributed

across Africa and Eurasia at least

a million years ago and evolved

in parallel into modern humans.

Then, in 1987, a bombshell. A team

of geneticists at the University of

J

EBEL IRHOUD, Morocco, 1961. In a

barium mine in the foothills of the

Atlas mountains, a miner makes a

ghoulish discovery: a near-complete

human skull embedded in the

sediment. Archaeologists called

in to investigate find that the skull

is old, but not that old. It is filed away

and largely forgotten.

Hinxton, UK, 2019. Robert Foley, a

palaeoanthropologist at the University

of Cambridge, is giving the opening

address at a three-day conference on

human evolution. “What I’m pretty

sure of is that, by the end of the first day,

something like 20 per cent of what I say

will be wrong,” he says to the hall. “By

the end of the second day, something

like 50 per cent will be wrong, and at the

end of the conference, I’m hoping that

something I said at the beginning still

holds true.”

Until recently, the story of our

origins was thought to be settled:

Homo sapiens evolved in eastern

Africa about 150,000 years ago, became

capable of modern behaviour some

60,000 years ago and then swept out

of Africa to colonise the world,

completely replacing any archaic

humans they encountered. But new

fossils, tools and analyses of ancient

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Features Cover story

BECOMING

HUMAN

The story of the origin of our species is being

radically rewritten. Graham Lawton discovers

the latest twists in the tale