Nav: Home

Ancient DNA shows European wipe-out of early Americans

April 01, 2016

The first largescale study of ancient DNA from early American people has confirmed the devastating impact of European colonisation on the Indigenous American populations of the time.

Led by the University of Adelaide's Australian Centre for Ancient DNA (ACAD), the researchers have reconstructed a genetic history of Indigenous American populations by looking directly into the DNA of 92 pre-Columbian mummies and skeletons, between 500 and 8600 years old.

Published today in Science Advances, the study reveals a striking absence of the pre-Columbian genetic lineages in modern Indigenous Americans; showing extinction of these lineages with the arrival of the Spaniards.

"Surprisingly, none of the genetic lineages we found in almost 100 ancient humans were present, or showed evidence of descendants, in today's Indigenous populations," says joint lead author Dr Bastien Llamas, Senior Research Associate with ACAD. "This separation appears to have been established as early as 9000 years ago and was completely unexpected, so we examined many demographic scenarios to try and explain the pattern."

"The only scenario that fit our observations was that shortly after the initial colonisation, populations were established that subsequently stayed geographically isolated from one another, and that a major portion of these populations later became extinct following European contact. This closely matches the historical reports of a major demographic collapse immediately after the Spaniards arrived in the late 1400s."

The research team, which also includes members from the University of California at Santa Cruz (UCSC) and Harvard Medical School, studied maternal genetic lineages by sequencing whole mitochondrial genomes extracted from bone and teeth samples from 92 pre-Columbian--mainly South American--human mummies and skeletons.

The ancient genetic signals also provide a more precise timing of the first people entering the Americas--via the Beringian land bridge that connected Asia and the north-western tip of North America during the last Ice Age.

"Our genetic reconstruction confirms that the first Americans entered around 16,000 years ago via the Pacific coast, skirting around the massive ice sheets that blocked an inland corridor route which only opened much later," says Professor Alan Cooper, Director of ACAD. "They spread southward remarkably swiftly, reaching southern Chile by 14,600 years ago."

"Genetic diversity in these early people from Asia was limited by the small founding populations which were isolated on the Beringian land bridge for around 2400 to 9000 years," says joint lead author Dr Lars Fehren-Schmitz, from UCSC. "It was at the peak of the last Ice Age, when cold deserts and ice sheets blocked human movement, and limited resources would have constrained population size. This long isolation of a small group of people brewed the unique genetic diversity observed in the early Americans."

Dr Wolfgang Haak, formerly at ACAD and now at the Max Planck Institute for the Science of Human History, says: "Our study is the first real time genetic record of these key questions regarding the timing and process of the peopling of the Americas. To get an even fuller picture, however, we will need a concerted effort to build a comprehensive dataset from the DNA of people alive today and their pre-Columbian ancestors, to further compare ancient and modern diversity."
-end-
Media Contact:

Dr Bastien Llamas
ARC Senior Research Associate
Australian Centre for Ancient DNA
School of Biological Sciences
The University of Adelaide
Mobile: +61 411 539 426
bastien.llamas@adelaide.edu.au

Professor Alan Cooper
Director, Australian Centre for Ancient DNA
School of Biological Sciences
The University of Adelaide
Phone: +61 8 8313 5950
Mobile: +61 (0)406 383 884
alan.cooper@adelaide.edu.au

Robyn Mills
Media Officer
The University of Adelaide
Phone: +61 8 8313 6341
Mobile: +61 (0)410 689 084
robyn.mills@adelaide.edu.au

University of Adelaide

Related Dna Articles:

Penn State DNA ladders: Inexpensive molecular rulers for DNA research
New license-free tools will allow researchers to estimate the size of DNA fragments for a fraction of the cost of currently available methods.
It is easier for a DNA knot...
How can long DNA filaments, which have convoluted and highly knotted structure, manage to pass through the tiny pores of biological systems?
How do metals interact with DNA?
Since a couple of decades, metal-containing drugs have been successfully used to fight against certain types of cancer.
Electrons use DNA like a wire for signaling DNA replication
A Caltech-led study has shown that the electrical wire-like behavior of DNA is involved in the molecule's replication.
Switched-on DNA
DNA, the stuff of life, may very well also pack quite the jolt for engineers trying to advance the development of tiny, low-cost electronic devices.
Researchers are first to see DNA 'blink'
Northwestern University biomedical engineers have developed imaging technology that is the first to see DNA 'blink,' or fluoresce.
Finding our way around DNA
A Salk team developed a tool that maps functional areas of the genome to better understand disease.
A 'strand' of DNA as never before
In a carefully designed polymer, researchers at the Institute of Physical Chemistry of the Polish Academy of Sciences have imprinted a sequence of a single strand of DNA.
Doubling down on DNA
The African clawed frog X. laevis genome contains two full sets of chromosomes from two extinct ancestors.
'Poring over' DNA
Church's team at Harvard's Wyss Institute for Biologically Inspired Engineering and the Harvard Medical School developed a new electronic DNA sequencing platform based on biologically engineered nanopores that could help overcome present limitations.

Related Dna Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Don't Fear Math
Why do many of us hate, even fear math? Why are we convinced we're bad at it? This hour, TED speakers explore the myths we tell ourselves and how changing our approach can unlock the beauty of math. Guests include budgeting specialist Phylecia Jones, mathematician and educator Dan Finkel, math teacher Eddie Woo, educator Masha Gershman, and radio personality and eternal math nerd Adam Spencer.
Now Playing: Science for the People

#518 With Genetic Knowledge Comes the Need for Counselling
This week we delve into genetic testing - for yourself and your future children. We speak with Jane Tiller, lawyer and genetic counsellor, about genetic tests that are available to the public, and what to do with the results of these tests. And we talk with Noam Shomron, associate professor at the Sackler School of Medicine at Tel Aviv University, about technological advancements his lab has made in the genetic testing of fetuses.