We Are All Africans

Researchers sequence the genomes from more isolated populations

By Bridget Alex
Dec 22, 2016 12:00 AMMay 17, 2019 10:17 PM
DSC-B0217 12
A 3,000-year-old pictograph from southern Africa depicts humans on the move. Peter Chadwick/Science Source

Newsletter

Sign up for our email newsletter for the latest science news
 

Every person’s DNA contains part of the human story: how our ancestors — lanky, tool-using apes — spread across the planet, colonizing environments as varied as the Himalayas, Arctic and Amazon Basin.

Millions of people have had at least part of their DNA studied, but because they’re mostly urban Westerners and East Asians, the samples repeat the same details of that story. From this data, we’ve known for three decades that Homo sapiensevolved in Africa some 200,000 years ago. To answer when and how humans migrated out of Africa, researchers needed DNA from a wider pool of people.

Three research groups sequenced high-quality genomes of 787 people from over 270 populations. Their findings were published concurrently in Nature in September. Two of the studies drew samples from isolated groups across the globe to maximize linguistic and cultural diversity. The third focused on indigenous people of Australia and Papua New Guinea.

“Genomes from these more remote populations really can tell us a huge amount about human evolutionary history,” says Evelyn Jagoda, a Harvard University evolutionary genetics Ph.D. student and co-author of one of the studies.

Although each team collected and analyzed genomes independently, they came to the same general conclusion: Genetic similarities between peoples of Eurasia, Oceania and the Americas indicate that all non-Africans descend from a small population that left Africa roughly 60,000 years ago.

Older Homo sapiens made it out of Africa, but these populations must have mostly died out. Only one of the three studies detected a trace of their existence: About 2 percent of the genomes of Papuans are probably from these earlier migrants.

Researchers hope to use the new data to find population-specific diseases and adaptations. There are still many things to be learned, says Nick Patterson, a Broad Institute computational biologist and a study co-author. “This data is extremely rich.”

1 free article left
Want More? Get unlimited access for as low as $1.99/month

Already a subscriber?

Register or Log In

1 free articleSubscribe
Discover Magazine Logo
Want more?

Keep reading for as low as $1.99!

Subscribe

Already a subscriber?

Register or Log In

More From Discover
Recommendations From Our Store
Shop Now
Stay Curious
Join
Our List

Sign up for our weekly science updates.

 
Subscribe
To The Magazine

Save up to 40% off the cover price when you subscribe to Discover magazine.

Copyright © 2024 Kalmbach Media Co.