DNA evidence tells 'global story' of human history

Feb 22, 2010

In recent years, DNA evidence has added important new tools for scientists studying the human past. Now, a collection of reviews published by Cell Press in a special issue of Current Biology published online on February 22nd offers a timely update on how new genetic evidence, together with archaeological and linguistic evidence, has enriched our understanding of human history on earth.

"To understand what it is to be human, it is essential to understand the human past," says Colin Renfrew of the University of Cambridge, who first coined the term "archaeogenetics" and is the author of a guest editorial in the special issue. "Nearly all civilizations have their own origin or creation myth. Now we can use archaeogenetics to tell a global story that is robust and applicable to all human communities everywhere."

The journey started around 60 to 70 thousand years ago in Africa, where evolved more than 150 thousand years ago, and where human diversity is still the highest among all continents in terms of and languages. From there, humans settled Europe and South Asia and reached Oceania. The Americas (apart from the remote Oceanian islands) were settled last.

The course and the extent of these first migrations remains evident in the of humans living today, but later migrations and the cultural practices that people carried with them—farming in particular—have also left their legacy. That legacy looks remarkably similar wherever farming spread, in Europe, Africa, and East Asia. Natural selection also left its mark: A review by Jonathan Pritchard of the University of Chicago examines evidence for the genetic basis of human adaptations and the extent to which differences among human populations in characteristics such as lactose tolerance have been selected for over evolutionary time.

Each of the reviews is packed with fascinating insights. For instance, a review by Mark Stoneking and Frederick Delfin at the Max Planck Institute for Evolutionary Anthropology tells of an early migration of modern humans from Africa along a southern route to East Asia. Europe is perhaps the best-studied continent in terms of archaeogenetics, writes Martin Richards of the University of Leeds and his colleagues, and includes what Richards refers to as five major episodes, including the repopulation of Northern Europe after the Late Glacial Maximum. In the case of the Americas, has confirmed the Asian origin of indigenous Americans and more precise estimates of when Native Americans emerged. Dennis O'Rourke and Jennifer Raff of the University of Utah note, however, that many questions about the date of the initial colonization of the Americas remain.

Overall, the reviews show just how clear it has become that all of us trace our evolutionary roots to Africa, Renfrew says. For most of history, humans were not evolving in isolation on separate continents. When it comes to our more recent history, stay tuned: Many surprising discoveries are likely in store over the next 20 years.

Of course, there are many things about our ancient ancestors we will never be able to know with any certainty, Partha Majumder of the Indian Statistical Institute reminds us in his review of human genetic history in South Asia.

"About 100,000 years ago, a small group of anatomically modern humans migrated out of Africa," he writes. "We will never know for sure which causes initiated this migration... The process continued for thousands of years; today humans occupy the entire world."

Explore further: How hummingbirds evolved to detect sweetness

Related Stories

The 'spread of our species'

Nov 08, 2005

Modern humans arrival in South Asia may have led to demise of indigenous populations. In a major new development in human evolutionary studies, researchers from the University of Cambridge argue that the dispersal of m ...

Australia discovered by the 'Southern Route'

Jul 21, 2009

Genetic research indicates that Australian Aborigines initially arrived via south Asia. Researchers writing in the open access journal BMC Evolutionary Biology have found telltale mutations in modern-day Indian populations that a ...

Recommended for you

Researchers look at small RNA pathways in maize tassels

6 hours ago

Researchers at the University of Delaware and other institutions across the country have been awarded a four-year, $6.5 million National Science Foundation grant to analyze developmental events in maize anthers ...

How plant cell compartments change with cell growth

6 hours ago

A research team led by Kiminori Toyooka from the RIKEN Center for Sustainable Resource Science has developed a sophisticated microscopy technique that for the first time captures the detailed movement of ...

Plants can 'switch off' virus DNA

6 hours ago

A team of virologists and plant geneticists at Wageningen UR has demonstrated that when tomato plants contain Ty-1 resistance to the important Tomato yellow leaf curl virus (TYLCV), parts of the virus DNA ...

A better understanding of cell to cell communication

7 hours ago

Researchers of the ISREC Institute at the School of Life Sciences, EPFL, have deciphered the mechanism whereby some microRNAs are retained in the cell while others are secreted and delivered to neighboring ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Nemo
not rated yet Feb 22, 2010
"About a thousand years ago" ?

Perhaps 100 thousand was meant here?
frajo
1 / 5 (1) Feb 23, 2010
We will never know for sure which causes initiated this migration...
Not for sure, but events like the Toba eruption roughly 75 ka ago might have initiated quite a lot of movement.
breadhead
1 / 5 (2) Feb 26, 2010
No proof of evolution whatsoever in this article.
But stay tuned folks, the words "evolution", and "millions of years" will appear in future articles, again, with no proof.
Arthur_Zombie
not rated yet Feb 26, 2010
breadhead,

I'm not too sure what premise your working from to explain life, but as of now, evolution is the prevailing theory. And by the way, religion is dogmatism, not theory.
MekaMekaMowMow
not rated yet Mar 20, 2010
My step father is a flaming christian, and his favorite argument about evolution is that our chromosomes don't match any other ape's. Apparently he "says" that if we originated from apes we would have the same chromosomes? What exactly is he talking about?