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Human Evolution

Timeline Topples

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FOR DECADES, SCHOOLCHILDREN ACROSS THE GLOBE were taught our origin story went something

like this: An archaic form of Homo sapiens evolved around 200,000 years ago in Africa. By about

100,000 years ago, the population had become anatomically modern humans who, around 50,

years ago, headed across Eurasia and met up with our distant cousins the Neanderthals (and the closely

related Denisovans, not known to science until 2010).

Like a game of Jenga, however, researchers have recently been removing bricks and destabilizing that

towering timeline. In 2017, a few more bricks came out, and the conventional chronology of our origins

finally toppled.

What we’re left with: Homo sapiens have been around at least 100,000 years longer than we thought, and

left Africa much earlier than we believed. And whenever they ran into other hominin populations, well...

“Sex happens,” says Erik Trinkaus, a paleoanthropologist at Washington University in St. Louis. “You can

draw lines of different lineages on maps, but real populations don’t behave that way.”

Trinkaus stresses that revising the timeline for human evolution isn’t the same as starting from scratch:

“The differences are of refinement, not in the basic story.”  GEMMA TARLACH

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THE ‘BIG WOW’

In the mid-20th century, during mining

operations at Jebel Irhoud in Morocco,

workers turned up some old, possibly human

bones. The haphazard find made dating them

confidently all but impossible.

Paleoanthropologist Jean-Jacques Hublin

and colleagues returned to the site recently to

excavate an area undisturbed by mining. They

hoped to find material that could help them

date the earlier discovery.

Instead, they found what Hublin calls

“a big wow”: the partial remains of at

least five humans, plus tools and other

artifacts, most of which are about

300,000 years old.

The archaic Homo sapiens’ facial

features and brain volume are essentially

modern, says Hublin, though their skulls’

shape is more primitive.

During a June news conference, shortly

before the study was published in Nature,

Hublin noted it’s unlikely the Jebel

Irhoud individuals, the oldest known

Homo sapiens fossils by about 100,

years, are our direct ancestors.

“We are not claiming that Morocco became

the cradle of modern humankind,” Hublin

says, “We think early forms of humans were

present all over Africa.”

And in the journal Science in late

September, a separate team offered additional

evidence of an earlier start date for our

species: By sequencing the ancient DNA of

seven individuals from southern Africa,

the researchers determined modern Homo

sapiens emerged up to 350,000 years ago.

SARAH FREIDLINE/MAX PLANCK INSTITUTE EVA LEIPZIG

Reconstruction

of an early

Homo sapiens

skull from the

Jebel Irhoud

site.