Fuente: https://www.sciencemag.org
Some of the world’s more famous and closely examined archaeological
sites pepper the hillsides of the Central Andes, documenting an
invention of farming and the rise and fall of powerful civilizations
such as the Inca. Now, the largest study of ancient human genomes in
South America has added a personal touch to the artifacts. The new
research reveals who lived there, when they lived, and how they moved
around and intermingled. And despite being a heavily studied area, a big
surprise emerged: Descendants of early inhabitants persisted even as
civilizations came and went.
“This paper sheds light on a region that’s home to some of the
world’s most intensively studied ancient societies during a particularly
dynamic period in its history,” says Jennifer Raff, an anthropological
geneticist at the University of Kansas, Lawrence, who was not involved
in the work. “Now, we are beginning to understand the biological history
as well” as the archaeological history.
The Central Andes Mountains, located mostly in today’s Peru, includes
coastal and highland regions. The Incas are the most well-known of the
ancient civilizations to live there: During their 100-year reign, until
the Spanish conquered them in the mid-1500s, they built an extensive
road system and constructed magnificent stone structures, such as Machu
Picchu. And they were preceded by several other well-developed
societies. The Moche lived there from 200 C.E. to 850 C.E. and are known
for having built giant adobe mounds with murals inside. Overlapping
partially in time were the Wari, known for fine textiles and terraced
agriculture. And there were other groups as well, such as the Nasca and
Tiwanaku.
Researchers from Harvard University and other institutions had already sequenced DNA from 9000-year-old human remains from
the Central Andes highlands as part of a broad survey of dozens of
South American ancient DNA samples. To get a more comprehensive look at
the genetic history of the region, teams led by Harvard population
geneticist David Reich and Lars Fehren-Schmitz, a paleogenomicist at the
University of California, Santa Cruz, joined with South American
colleagues and worked with local authorities to get DNA from many key
archaeological sites, sequencing 64 new ancient genomes. Using
radiocarbon dating, they determined the DNA belonged to people who lived
between 9000 to 500 years ago. The researchers compared those genomes
with each other and 25 already sequenced ancient samples.
The people who lived in the highlands 9000 years ago were genetically
distinct from ancient groups of people who inhabited the coastal region
and areas to the north and south, and have remained so even today,
Harvard graduate student Nathan Nakatsuka and his colleagues report today in Cell.
The highland genomic group even persisted despite several cultural
upheavals as the Inca, Moche, and others came and went in the past 2000
years. Such genetic stability contrasts with tumultuous events in
Eurasia during the same time; there, genetic studies have found evidence
of repeated replacements of local people by newcomers, Nakatsuka says.
“These data confirm what I and other researchers have proposed,” says
Francesca Giulietta Fernandini Parodi, an archaeologist at the
Pontifical Catholic University of Peru (PUCP): Repeated invasions did
not lead to the demise of local people.
Yet the highlands people were not isolated. In the large cities of
both the Inca and the Tiwanaku, the DNA in the new study indicated that
people from many different places lived side by side. “They were akin to
places like New York City,” says PUCP archaeologist Luis Jaime
Castillo.
More genomes might refine or even change this picture, cautions
Castillo, who hopes more DNA data will be forthcoming. Fernandini
welcomes the new data. “It is important to integrate our
[archaeological] studies with ancient DNA evidence to obtain a clearer
scenario,” she says. The work “is a major advance in the study of
ancient Andean populations.”
MÁS INFORMACIÓN
- Divided by DNA: The uneasy relationship between archaeology and ancient genomics
- On the use and abuse of ancient DNA
- Cita CDXXII: Un par de gemelos, un solo delincuente. Las pruebas de ADN para resolver crímenes
No hay comentarios:
Publicar un comentario