How Science Works - Discovering the Unexpected History of the First Americans

The Alcobaça archaeological site, in which the skeletal remains of Brazil-12 (northeast Brazil) were unearthed.

Photo credit: Henry Lavalle, Universidade Federal de Pernambuco
and Ana Nascimento, Universidade Federal Rural de Pernambuco)

FAU | Ancient DNA Analysis Unravels the Early Peopling of South America

Despite the claims of Creationist frauds, scientific papers are not, like Creationist articles on Creationist websites, vetted to ensure they simply regurgitates the approved orthodoxy. Indeed, science would stagnate just like Creationism if that were the case. Instead, science progresses by discovering the unorthodox and revealing the unknown.

Sometimes, as in the case of this paper by scientists from Florida Atlantic University in collaboration with researchers from Emory University, Atlanta, GA, USA it turns what we think we know on its head and causes us to rethink things. Like deconstructing part of jigsaw puzzle and throwing the pieces into the air.

The research concerns the origins of the native people of South America. The consensus view was that modern humans crossed from Siberia when sea levels were lower, and what is now the Bering Strait, between Siberia and Alaska, known as Beringia was habitable. From there, they spread south into North America and continued down the Pacific coast, over the Central American isthmus and into South America. Previous genetic studies had seems to support this showing a connection with ancient people from the Altai region of Siberian Central Asia.

However, the genome of two ancient individuals from two different sites in Northern Brazil, at Pedra do Tubarão and Alcobaça, using powerful algorithms and genomic analyses, shows a different story. They show that, not only had there been interbreeding between the ancestors of these people and Neanderthals, but that they also discovered more Denisovan than Neanderthal ancestry in ancient Uruguay and Panama individuals. This is not inconsistent with the Beringia migration theory, of course, but it is the discovery of what happened next, and where this other hominin species DNA came from where the surprise it.

They also found a mysterious and as yet unexplained strong genetic signal linking Australasian (Australia and Papua New Guinea) to an ancient genome from Panama.

Lastly, unexpectedly, they found evidence that there was a northward migration from South America up the Atlantic coast after people had become established east of the Andes.

As the Florida Atlantic University News release explains:

Using DNA from two ancient human individuals unearthed in two different archaeological sites in northeast Brazil – Pedra do Tubarão and Alcobaça – and powerful algorithms and genomic analyses, Florida Atlantic University researchers in collaboration with Emory University have unraveled the deep demographic history of South America at the regional level with some unexpected and surprising results.

Not only do researchers provide new genetic evidence supporting existing archaeological data of the north-to-south migration toward South America, they also have discovered migrations in the opposite direction along the Atlantic coast – for the first time. The work provides the most complete genetic evidence to date for complex ancient Central and South American migration routes.

Among the key findings, researchers also have discovered evidence of Neanderthal ancestry within the genomes of ancient individuals from South America. Neanderthals are an extinct population of archaic humans that ranged across Eurasia during the Lower and Middle Paleolithic.

Results of the study, published in the journal Proceedings of the Royal Society B. (Biological Sciences), suggest that human movements closer to the Atlantic coast eventually linked ancient Uruguay and Panama in a south-to-north migration route – 5,277 kilometers (3,270 miles) apart. This novel migration pattern is estimated to have occurred approximately 1,000 years ago based on the ages of the ancient individuals.

Findings show a distinct relationship among ancient genomes from northeast Brazil, Lagoa Santa (southeast Brazil), Uruguay and Panama. This new model reveals that the settlement of the Atlantic coast occurred only after the peopling of most of the Pacific coast and Andes.

Our study provides key genomic evidence for ancient migration events at the regional scale along South America’s Atlantic coast. These regional events likely derived from migratory waves involving the initial Indigenous peoples of South America near the Pacific coast.

Michael DeGiorgio, Ph.D., co-corresponding author
Associate professor
Department of Electrical Engineering and Computer Science
College of Engineering and Computer Science
Florida Atlantic University, Boca Raton, FL, USA

Researchers also found strong Australasian (Australia and Papua New Guinea) genetic signals in an ancient genome from Panama.

There is an entire Pacific Ocean between Australasia and the Americas, and we still don’t know how these ancestral genomic signals appeared in Central and South America without leaving traces in North America.

Andre Luiz Campelo dos Santos, Ph.D., first author
Department of Electrical Engineering and Computer Science
College of Engineering and Computer Science
Florida Atlantic University, Boca Raton, FL, USA

To further add to the existing complexity, researchers also detected greater Denisovan than Neanderthal ancestry in ancient Uruguay and Panama individuals. Denisovans are a group of extinct humans first identified from DNA sequences from the tip of finger bone discovered around 2008.

It’s phenomenal that Denisovan ancestry made it all the way to South America. The admixture must have occurred a long time before, perhaps 40,000 years ago. The fact that the Denisovan lineage persisted and its genetic signal made it into an ancient individual from Uruguay that is only 1,500 years old suggests that it was a large admixture event between a population of humans and Denisovans.

John Lindo, Ph.D., co-corresponding author
Assistant professor
Department of Anthropology
Emory University, Atlanta, GA, USA

Previously at the Federal University of Pernambuco in Recife, Brazil, dos Santos and colleagues uncovered the remains of the two ancient humans from northeast Brazil, which date back to at least 1,000 years before present, and sent them to Lindo for DNA extraction and subsequent genomic sequencing and analyses. Raw data were then sent to FAU for computational analysis of the whole genome sequences from northeast Brazil.

This groundbreaking research involved many different fields from archaeology to biological sciences to genomics and data science. Our scientists at Florida Atlantic University in collaboration with Emory University have helped to shed light on an important piece of the Americas puzzle, which could not have been solved without powerful genomic and computational tools and analysis.

Stella Batalama, Ph.D.
Dean, College of Engineering and Computer Science.
Florida Atlantic University, Boca Raton, FL, USA

Researchers compared the two newly sequenced ancient whole genomes from northeast Brazil with present-day worldwide genomes and other ancient whole genomes from the Americas. As of the publication date of the article, Lindo says that only a dozen or so ancient whole genomes from South America have been sequenced and published, in contrast to hundreds from Europe.

Apart from the occurrence of mass burials in the sites that yielded the samples from northeast Brazil, Uruguay, southeast Brazil and Panama, there is no other evidence in the archaeological record that indicate shared cultural features among them. Importantly, the analyzed ancient individuals from southeast Brazil are about 9,000 years older than those from northeast Brazil, Uruguay and Panama, enough time for expected and noticeable cultural divergence. Moreover, northeast Brazil, Uruguay and Panama, though more similar in age, are located thousands of kilometers apart from each other.

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Genetic profile at key sites (left). Migration routes (right)

This research suggests that the people who eventually made it to South America, came from a people who had interbred extensively with Neanderthals and even more so with Denisovans, but how the Australasian DNA got to Panama remains to be discovered. The intriguing thing here is that the Australasians themselves have a high proportion of Denisovan DNA and Denisovans are assumed to have been present over much of east and south-east Asia, including the Altai area of Siberia where the first Denisovan remains were found.

As for the creationist claim that only scientific orthodoxy is permitted in peer-reviewed journals, papers like this that cast considerable doubt on the consensus view and raise so many unanswered questions, give the lie to that claim, but it is typical of Creationists that they accuse others of doing what they themselves do, as though accusing others of their own dishonesty somehow absolves them of responsibility for it.

Creationists who publish through sites like Answers in Genesis, or anyone who receives funding from the ICR or the Deception Discovery Institute, must sign an oath that they will never publish anything which isn't in full accord with a literal interpretation of the Bible in general and Genesis in particular. What ‘peer-review’ there is in Creationist circles is merely checking that the oath has been kept.

The Creationist Oath

As I said at the beginning, if Creationist accusations were true, science would be as stagnant as Creationism, never moving away from the handed-down orthodoxy of cult leaders. But as anyone who knows anything about science will know, science is a dynamic, evolving and expanding body of evidence-based knowledge that is responsible for modern technologies like electricity, radio and telephone communications, computers and modern transport systems as well as medicines, modern buildings, clean water and food production.

Without religion, all we would have is some people with nothing to do on holy days and having to take responsibility for their own beliefs and attitudes with nothing to blame and no excuses to justify their antisocial behaviour; imagine life without science.