60% of home ‘compostable’ plastic doesn’t fully break down, ending up in our soil

Peer-Reviewed Publication

FRONTIERS

 

IMAGE: COMPOSTABLE PLASTIC THAT HAS NOT FULLY DISINTEGRATED IN COMPOST BIN view more 

CREDIT: CITIZEN SCIENTIST IMAGE FROM WWW.BIGCOMPOSTEXPERIMENT.ORG.UK

In a UK-wide study, researchers found that 60% of home-compostable plastics do not fully disintegrate in home compost bins, and inevitably end up in our soil. The study also found that citizens are confused about the labels of compostable and biodegradable plastics, leading to incorrect plastic waste disposal. These results highlight the need to revise and redesign this supposedly sustainable plastic waste management system.

Global plastic pollution remains one of the biggest environmental challenges of our time. A new OECD report shows that plastic consumption has quadrupled over the past 30 years. Globally, only 9% of plastic waste is recycled, while 50% ends up in landfills, 22% evades waste management systems, and 19% is incinerated.

In response to this pollution crisis, several countries have set targets to eliminate all single-use plastics and to make plastic packaging 100% recyclable, reusable, or compostable by 2025. 

Compostable plastics are becoming more common as the demand for sustainable products grows. The main applications of compostable plastics include food packaging, bags; cups and plates, cutlery, and bio-waste bags. But there are some fundamental problems with these types of plastics. They are largely unregulated and claims around their environmental benefits are often exaggerated. 

Now, in a new study published in Frontiers in Sustainability, researchers at University College London found that consumers are often confused about the meaning of the labels of compostable plastics, and that a large portion of compostable plastics do not fully disintegrate under home composting conditions.

(Un)compostable plastics

‘Compostable plastic’ describes a material that can undergo biological degradation in a compost site at a rate consistent with other known compostable materials, leaving no visible (toxic) residues.

However, compostable plastics are currently incompatible with most waste management systems. There exists no harmonized international standard for home compostable plastics. The fate of these plastics, when thrown away or sorted for recycling, is therefore either incineration or landfill. 

“The typical fate of landfill or incineration is not usually communicated to customers so the environmental claims made for compostable packaging can be misleading,” said corresponding author Danielle Purkiss.

The Big Compost Experiment

Purkiss and her colleagues designed a three-part citizen science study, The Big Compost Experiment, to investigate what the public thinks about home compostable plastics, how we deal with them, and whether they fully disintegrate in our compost. 

First, participants from across the UK completed an online survey about opinions and behavior surrounding compostable plastics and food waste. Then, participants were invited to take part in a home composting experiment. Lastly, those who participated in part two were sent a request to search for traces of their chosen compostable plastic items in their composter. The researchers collected the data over a period of 24 months.

“Our study was created in response to feedback from the public and stakeholders from industry, policy, and third sector organizations, which highlighted many systemic issues in the manufacturing, use, and disposal of compostable plastic packaging,” explained Purkiss.

The results show a general willingness to make sustainable choices by buying compostable plastics. However, participants showed confusion about the labeling and identification of these plastics. Out of a randomized sample of 50 item images, the researchers found that 46% showed no identifiable home composting certification or standards labeling and 14% showed industrial composting certification.

“This shows that there is a current lack of clear labeling and communication to ensure that the public can identify what is industrially compostable or home compostable packaging, and how to dispose of it correctly,” said Purkiss.

But a more shocking result is that 60% of plastic certified as home compostable did not fully disintegrate in home compost bins. 

“Compostable packaging does not break down effectively in the range of UK home composting conditions, creating plastic pollution,” Purkiss added. “Even packaging that has been certified as home compostable is not breaking down effectively.”

The participants indicated that they use their compost in their flower and vegetable gardens. As the results of the experiment show that the compost contains plastic that has not fully disintegrated, plastic inevitably ends up in soil of UK citizens. 

The experiment also showed that compost bins are important sites for biodiversity, with pictures sent in by the participants showing 14 different categories of organisms such as fungi, mites, and worms.

Revising the system

The question remains whether compostable plastics serve as a solution to our widespread plastic pollution problem.

“Compostable plastics are potentially useful for products that are not suited to recycling due to contamination such as tea bags, fruit labels, take-away food packaging, and certain hygiene products. These products typically end up in landfill,” explained Purkiss. 

But the research shows that, in this case, the better solution is to send compostable plastics to industrial composting facilities, where composting conditions are regulated.

“We have shown that home composting, being uncontrolled, is largely ineffective and is not a good method of disposal for compostable packaging,” said Purkiss.

Overall, there is a need for the revision and improvement of home compostable plastics. “The idea that a material can be sustainable is a widespread misconception. Only a system of production, collection, and reprocessing of a material can be sustainable,” concluded Purkiss.

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JOURNAL

Frontiers in Sustainability

DOI

10.3389/frsus.2022.942724 

“The Ripple Effect” new study illustrates vast influence children’s mental health concerns have on workforce challenges in America

On Our Sleeves® releases new data that shows one-third of working parents report changing or quitting their jobs during the past two years because of their child’s mental health

Reports and Proceedings

NATIONWIDE CHILDREN'S HOSPITAL

COLUMBUS, Ohio (November 3, 2022) – As the American economy has undergone rapid and dramatic change, so too has America’s workforce. Trending terms, such as “the great resignation” and “quiet quitting,” have been coined as we seek to better understand workplace challenges across the country. There have been many contributing factors reported to be driving these issues, but new research shows that the pediatric mental health crisis is a significant and surprising contributor among working parents in America’s workforce. 

In a first of its kind national study conducted by On Our Sleeves, the movement for children’s mental health, the “Great Collide” found that employees' work performance and productivity were negatively impacted by their children’s mental health.

Now, in its second iteration, “The Ripple Effect” study from On Our Sleeves found that the mental health of their children remains a concern for the large majority of working parents, with almost half of all parents reporting that in the past year their child's mental health has been somewhat or extremely disruptive to their ability to work on most days.

“After discovering the impact that children’s mental health was having on the national workforce, it was important for us to dig in deeper and flesh out the scope of the impact and look for ways to provide relief to parents and employers,” Marti Bledsoe Post, executive director of On Our Sleeves, said. “Having these honest conversations can be difficult and new to many parents, but, luckily, this data points to solutions.”

In addition to daily work disruptions, many working parents reported long-term disruptions to their careers due to their children’s mental health. For working parents who feel as though they’ve been placed in a position to choose between their child and their work, the choice is clear - with one-third (32%) of working parents reporting that they’ve changed or quit their job during the past two years because of their child’s mental health.

“I left my job to adjust my schedule and workload around my kids. My kids were suffering and I was too exhausted to come home and address things going on. I knew I needed to let the job go because it was affecting my entire household.” Demetris, a working mom, said.

Furthermore, among parents who still have some degree of concerns and interruptions regarding their child’s mental health, significantly more Black/African-American parents (37%) reported changing their work arrangements because of their child’s mental health than white-only parents (26%).

With so many working parents struggling, On Our Sleeves also asked what would help ease the strain they were feeling and make them more likely to stay with their employer. Many pointed to the need for collaboration with their employers to address the impact of their children’s mental health on their work.

Nearly three-quarters of working parents surveyed said jobs that provide their children with mental health benefits and resources are more attractive than jobs that do not offer such benefits.

“We’re seeing that caregivers will choose family over work if the mental health needs of their child are involved, and so the U.S. workforce will continue to be affected by pediatric mental health,” said Dr. Ariana Hoet, clinical director of On Our Sleeves and pediatric psychologist at Nationwide Children’s Hospital. “Our kids are having a hard time and, as a result, their caregivers are too. Equipping caregivers and their employers with resources to address youth mental health is key to our path forward.”

On Our Sleeves is pushing for changes across the country. As a national advocate in the youth mental health movement, U.S. Surgeon General Dr. Vivek Murthy recently traveled to meet with pediatric behavioral health experts at On Our Sleeves  and Nationwide Children’s Hospital to discuss the study and actions being taken right now to protect youth mental health.

“We must all work together to address the youth mental health crisis and improve mental health at work. This research reinforces the fact that youth mental health impacts not only children but also parents, caregivers and employers,” said U.S. Surgeon General Dr. Vivek Murthy. “My Surgeon General’s Advisory on Youth Mental Health and Framework on Mental Health and Well-Being in the Workplace both outline steps that employers can take to support the mental health of their employees and their families, recognizing that employers have a role to play as we work to lay the foundation for a healthier nation.”

Striving to provide the best possible work environment for its employees, Nationwide Insurance’s foundation, the Nationwide Foundation, partnered with On Our Sleeves to help fund this important research. The hope is to raise awareness of the challenges many working parents face and that more companies nationwide will be able to create a safe space for their employees to thrive.

“As business leaders, it’s important for us to understand what an employee needs in order to be successful in the workplace.” said Vinita Clements, Executive Vice President & Chief of Human Resources at Nationwide Insurance whose Foundation funded the study. “By fostering a work environment where employees feel comfortable opening up, we’re able to better provide support.”

For more information regarding the findings of this study or to find resources related to pediatric mental health, please visit https://www.onoursleeves.org/about/research/ripple-effect.

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About On Our Sleeves®
Children don’t wear their thoughts on their sleeves. With 1 in 5 children living with a significant mental health concern and half of all lifetime mental health concerns starting by age 14, we need to give them a voice. On Our Sleeves®, powered by behavioral health experts at Nationwide Children’s Hospital, aims to provide every community in America with free resources necessary for breaking child mental health stigmas and educating families and advocates, because no child or family should struggle alone.

Since the inception of On Our Sleeves® in 2018, more than 3 million people in every state across America have interacted with the movement’s free pediatric mental health educational resources at OnOurSleeves.org and educator curriculums have reached more than four of five classrooms across the United States.

About Nationwide Children’s Hospital’s Behavioral Health Services & The Big Lots Behavioral Health Pavilion
As a national leader in pediatric behavioral and mental health, Nationwide Children’s Hospital’s Big Lots Behavioral Health Services offers a comprehensive, team approach which brings together more than 1,100 staff members in psychiatry, psychology, pediatrics, advanced practice providers, nursing, counseling, social work, clinical therapies and parent support specialists to help with every aspect of a child’s treatment for more than 257,000 visits. This includes the Big Lots Behavioral Health Pavilion, America’s largest treatment and research center on a pediatric medical campus. Nationwide Children’s Behavioral Health is also the creator of the On Our Sleeves movement for children’s mental health, aimed at providing every community in America with free, evidence-informed resources.

About the Nationwide Foundation
The Nationwide Foundation, established in 1959, is a nonprofit, private foundation to which Nationwide companies are the donors. Their mission is to improve the quality of life in communities in which a large number of Nationwide members, associates, partners and their families live and work. Since 2000, the Nationwide Foundation has contributed more than $550 million to nonprofit organizations across the country that work to meet crucial needs in communities with a significant presence of Nationwide associates.

Waterloo researchers discover security loophole allowing attackers to use WiFi to see through walls

Drone-powered device exposes vulnerabilities in WiFi security

Reports and Proceedings

UNIVERSITY OF WATERLOO

A research team based out of the University of Waterloo has developed a drone-powered device that can use WiFi networks to see through walls.

The device, nicknamed Wi-Peep, can fly near a building and then use the inhabitants’ WiFi network to identify and locate all WiFi-enabled devices inside in a matter of seconds. 

The Wi-Peep exploits a loophole the researchers call polite WiFi. Even if a network is password protected, smart devices will automatically respond to contact attempts from any device within range. The Wi-Peep sends several messages to a device as it flies and then measures the response time on each, enabling it to identify the device’s location to within a metre. 

Dr. Ali Abedi, an adjunct professor of computer science at Waterloo, explains the significance of this discovery. 

“The Wi-Peep devices are like lights in the visible spectrum, and the walls are like glass,” Abedi said. “Using similar technology, one could track the movements of security guards inside a bank by following the location of their phones or smartwatches. Likewise, a thief could identify the location and type of smart devices in a home, including security cameras, laptops, and smart TVs, to find a good candidate for a break-in. In addition, the device’s operation via drone means that it can be used quickly and remotely without much chance of the user being detected.”

While scientists have explored WiFi security vulnerability in the past using bulky, expensive devices, the Wi-Peep is notable because of its accessibility and ease of transportation. Abedi’s team built it using a store-bought drone and $20 of easily purchased hardware. 

“As soon as the Polite WiFi loophole was discovered, we realized this kind of attack was possible,” Abedi said. 

The team built the Wi-Peep to test their theory and quickly realized that anyone with the right expertise could easily create a similar device.

“On a fundamental level, we need to fix the Polite WiFi loophole so that our devices do not respond to strangers,” Abedi said. “We hope our work will inform the design of next-generation protocols.” 

In the meantime, he urges WiFi chip manufacturers to introduce an artificial, randomized variation in device response time, which will make calculations like the ones the Wi-Peep uses wildly inaccurate. 

The paper summarizing this research, Non-cooperative wi-fi localization & its privacy implications, was presented at the 28th Annual International Conference on Mobile Computing and Networking. 

Breast cancer survivorship doubles

Peer-Reviewed Publication

UNIVERSITY OF TORONTO

It was the information she couldn’t find that led Amy Kirkham, an assistant professor in the University of Toronto’s Faculty of Kinesiology & Physical Education (KPE), to her latest discovery.

Asked by the Canadian Women’s Heart Health Alliance to co-author a scientific statement paper in 2020 on the state of women’s heart health in Canada, Kirkham - whose research is focused on preventing and treating the risk of heart disease related to breast cancer treatment – needed to know what percentage of the Canadian female population has a history of breast cancer.

But the most recent statistic she could find – one percent – was from 2007.

“Nearly 15 years had passed and I could not find a more recent citation about the prevalence of breast cancer survivors in Canada,” says Kirkham. “Breast cancer mortality rates had continued to improve 26 per cent over this time period, so I suspected that this number was no longer accurate.”

So, in collaboration with Katarzyna Jerzak, a medical oncologist at Sunnybrook Odette Cancer Centre and assistant professor in the department of medicine in U of T’s Temerty Faculty of Medicine, Kirkham embarked on a new study that would determine an up-to-date estimate of the prevalence of breast cancer survivors in Canada in 2022 using the Canadian Cancer Society’s annual cancer statistic reports.

The study, recently published in the Journal of the National Comprehensive Cancer Network, found that in the 15-year span from 2007 to 2021, there were 370,756 patients (2.1 per cent of the adult female population in Canada in 2022) diagnosed with breast cancer and 86 per cent of these women would have survived breast cancer by 2022. 

“This indicates that the prevalence of breast cancer survivors in the Canadian female population has doubled and that there are 2.5 times more survivors since the last estimate in 2007,” says Kirkham. 

The prior estimate did not include the age group of survivors, but according to the new estimate provided by Kirkham and Jerzak, breast cancer survivors represent one per cent of Canadian women in the typical working and/or child-raising age group (20 to 64 years) and 5.4 per cent of senior (aged 65-plus) Canadian women. 

But it’s not all good news.

Many of the treatments that have improved breast cancer mortality rates also cause short-term and long-term side effects, which, in turn, can raise the risk of death from other causes such as heart disease, stroke, Alzheimer’s disease, liver disease and other non-fatal health outcomes.

“The most common cause of death in women with breast cancer is heart disease,” Kirkham says. 

Such conditions also affect overall health-care costs.

To demonstrate the excess health-care costs related to heart disease, Kirkham and Jerzak performed an additional analysis using Canadian data on rates of hospitalization for heart failure and their costs. They found that two per cent of the women diagnosed with breast cancer between 2007 and 2021 would likely experience heart failure hospitalization costing $66.5 million in total. As much as 25 per cent of these costs, or $16.5 million, were in excess of those costs that would be associated with women who did not have breast cancer. 

“Given the excess health-care costs, potential for reduced contributions to the workforce and reduced quality of life associated with long-term side effects and risk of excess death among breast cancer survivors, our work highlights that there is a growing segment of the population who require services to support recovery following breast cancer treatment," says Kirkham.

“The goal of my research lab is to develop new therapies to improve the health of women after surviving breast cancer.” 

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JOURNAL

Journal of the National Comprehensive Cancer Network

DOI

10.6004/jnccn.2022.7028 

METHOD OF RESEARCH

Data/statistical analysis

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Prevalence of Breast Cancer Survivors Among Canadian Women

Revealed: oldest star clusters in the universe

Peer-Reviewed Publication

UNIVERSITY OF TORONTO

 

IMAGE: THOUSANDS OF GALAXIES FLOOD THIS NEAR-INFRARED, HIGH-RESOLUTION IMAGE OF GALAXY CLUSTER SMACS 0723 view more 

CREDIT: PHOTO COURTESY OF NASA, ESA, CSA, STSCI

A team of Canadian astronomers, including experts from the Dunlap Institute for Astronomy & Astrophysics in the University of Toronto's Faculty of Arts & Science, have used the James Webb Telescope (JWST) to identify the most distant globular clusters ever discovered – dense groups of millions of stars that may be relics containing the first and oldest stars in the universe.

The early analysis of Webb’s First Deep Field image, which depicts some of the universe’s earliest galaxies, was published Sept. 29 in The Astrophysical Journal Letters.

“JWST was built to find the first stars and the first galaxies and to help us understand the origins of complexity in the universe, such as the chemical elements and the building blocks of life,” says Lamiya Mowla, a post-doctoral researcher at the Dunlap Institute for Astronomy & Astrophysics and co-lead author of the study, which was carried out by the CAnadian NIRISS Unbiased Cluster Survey (CANUCS) team.

“This discovery in Webb’s First Deep Field is already providing a detailed look at the earliest phase of star formation, confirming the incredible power of JWST.”

In the finely detailed Webb’s First Deep Field image, the researchers zeroed in on what they’ve dubbed “the Sparkler galaxy,” which is nine billion light years away. This galaxy got its name for the compact objects appearing as small yellow-red dots surrounding it, referred to by the researchers as “sparkles.” The team posited that these sparkles could either be young clusters actively forming stars – born three billion years after the Big Bang at the peak of star formation – or old globular clusters. Globular clusters are ancient collections of stars from a galaxy’s infancy and contain clues about its earliest phases of formation and growth.

From their initial analysis of 12 of these compact objects, the researchers determined that five of them are not only globular clusters but among the oldest ones known.

“Looking at the first images from JWST and discovering old globular clusters around distant galaxies was an incredible moment – one that wasn’t possible with previous Hubble Space Telescope imaging,” says Kartheik G. Iyer, a post-doctoral researcher at the Dunlap Institute for Astronomy & Astrophysics and co-lead author of the study.

“Since we could observe the sparkles across a range of wavelengths, we could model them and better understand their physical properties – like how old they are and how many stars they contain. We hope the knowledge that globular clusters can be observed at from such great distances with JWST will spur further science and searches for similar objects.”

The Milky Way galaxy is known to have about 150 globular clusters, but how and when exactly these dense clumps of stars formed is not well understood. Astronomers know that globular clusters can be extremely old, but it is incredibly challenging to measure their ages. Using very distant globular clusters to age-date the first stars in distant galaxies has not been done before and is only possible with JWST.

“These newly identified clusters were formed close to the first time it was even possible to form stars,” says Mowla. “Because the Sparkler galaxy is much farther away than our own Milky Way, it is easier to determine the ages of its globular clusters. We are observing the Sparkler as it was nine billion years ago, when the universe was only four-and-a-half billion years old, looking at something that happened a long time ago. Think of it as guessing a person's age based on their appearance – it’s easy to tell the difference between a five- and 10-year-old, but hard to tell the difference between a 50- and 55-year-old.”

Until now, astronomers could not see the surrounding compact objects of the Sparkler galaxy with the Hubble Space Telescope. This changed with JWST's increased resolution and sensitivity, unveiling the tiny dots surrounding the galaxy for the first time in Webb’s First Deep Field image. The Sparkler galaxy is special because it is magnified by a factor of 100 due to an effect called gravitational lensing – where the SMACS 0723 galaxy cluster in the foreground distorts what is behind it, much like a giant magnifying glass. Moreover, gravitational lensing produces three separate images of the Sparkler, allowing astronomers to study the galaxy in greater detail.

“Our study of the Sparkler highlights the tremendous power in combining the unique capabilities of JWST with the natural magnification afforded by gravitational lensing,” says CANUCS team lead Chris Willott from the National Research Council’s Herzberg Astronomy and Astrophysics Research Centre. “The team is excited about more discoveries to come when JWST turns its eye on the CANUCS galaxy clusters next month.”

The researchers combined new data from JWST’s Near-Infrared Camera (NIRCam) with Hubble Scape Telescope archival data. NIRCam detects faint objects using longer and redder wavelengths to observe past what is visible to the human eye and even the Hubble Space Telescope. Both magnifications due to the lensing by the galaxy cluster and the high resolution of JWST are what made observing compact objects possible.

The Canadian-made Near-Infrared Imager and Slitless Spectrograph (NIRISS) instrument on the JWST provided independent confirmation that the objects are old globular clusters because the researchers did not observe oxygen emission lines – emissions with measurable spectra given off by young clusters that are actively forming stars. NIRISS also helped unravel the geometry of the triply lensed images of the Sparkler.

“JWST’s made-in-Canada NIRISS instrument was vital in helping us understand how the three images of the Sparkler and its globular clusters are connected,” says Marcin Sawicki, a professor at Saint. Mary's University who is Canada Research Chair in Astronomy and co-author of the study. “Seeing several of the Sparkler’s globular clusters imaged three times made it clear that they are orbiting around the Sparkler galaxy rather than being simply in front of it by chance.”

JWST will observe the CANUCS fields starting in October 2022, leveraging its data to examine five massive clusters of galaxies, around which the researchers expect to find more such systems. Future studies will also model the galaxy cluster to understand the lensing effect and execute more robust analyses to explain the star formation histories.

Collaborating institutions include York University and institutions in the United States and Europe. The research was supported by the Canadian Space Agency and the Natural Sciences and Engineering Research Council of Canada.

CAPTION

The researchers studied the Sparkler galaxy located in Webb’s First Deep Field and used JWST to determine that five of the sparkling objects around it are globular clusters.

CREDIT

Image via Canadian Space Agency with images from NASA, ESA, CSA, STScI; Mowla, Iyer et al. 2022.

CAPTION

From left: Kartheik Iyer, Vince Estrada-Carpenter, Guillaume Desperez, Lamiya Mowla, Marcin Sawicki, Victoria Strait, Gabe Brammer and Kate Gould (on laptop screen), Ghassan Sarrouh, Chris Willott, Bob Abraham, Gael Noirot, Yoshi Asada, Nick Martis

CREDIT

Photo courtesy of Lamiya Mowla and Kartheik Iyer

CAPTION

Gravitational lensing is used by astronomers to study very distant and very faint galaxies.

CREDIT

Image courtesy of NASA, ESA & L. Calçada

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JOURNAL

The Astrophysical Journal Letters

DOI

10.3847/2041-8213/ac90ca 

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

The Sparkler: Evolved High-redshift Globular Cluster Candidates Captured by JWST

Ancient DNA analysis sheds light on the early peopling of South America

Study provides most complete genetic evidence to date of complex migration routes in Ancient Central and South America

Peer-Reviewed Publication

FLORIDA ATLANTIC UNIVERSITY

 

IMAGE: THE FIRST SOUTHERN NORTH AMERICAN GROUPS ENTERED SOUTH AMERICA AND SPREAD THROUGH THE PACIFIC COAST SETTLING THE ANDES (YELLOW ARROW). AT LEAST ONE POPULATION SPLIT OCCURRED SOON AFTER, BRANCHING THE FIRST GROUPS THAT SETTLED THE ATLANTIC COAST (GREEN ARROW) FROM THE GROUPS THAT GAVE RISE TO THE ANCIENT POPULATIONS OF SOUTHERN CONE. NEW MIGRATIONS MAY HAVE THEN EMERGED ALONG THE ATLANTIC COAST, WITH A POSSIBLE ORIGIN AROUND LAGOA SANTA, HEADING NORTH TOWARD NORTHEAST BRAZIL AND PANAMA, AND SOUTH TO URUGUAY. EVENTUALLY, URUGUAY AND PANAMA WERE LINKED BY A SOUTH-TO-NORTH MIGRATION ROUTE CLOSER TO THE ATLANTIC COAST (PURPLE DOUBLE-HEADED ARROW). view more 

CREDIT: FLORIDA ATLANTIC UNIVERSITY

The Americas were the last continent to be inhabited by humans. An increasing body of archaeological and genomic evidence has hinted to a complex settlement process. This is especially true for South America, where unexpected ancestral signals have raised perplexing scenarios for the early migrations into different regions of the continent.

Many unanswered questions still persist, such as whether the first humans migrated south along the Pacific coast or by some other route. While there is archaeological evidence for a north-to-south migration during the initial peopling of the Americas by ancient Indigenous peoples, where these ancient humans went after they arrived has remained elusive.  

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,” said Michael DeGiorgio, Ph.D., co-corresponding author who specializes in human, evolutionary, and computational genomics and is an associate professor in the Department of Electrical Engineering and Computer Science within FAU’s College of Engineering and Computer Science. “These regional events likely derived from migratory waves involving the initial Indigenous peoples of South America near the Pacific coast.”

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,” said Andre Luiz Campelo dos Santos, Ph.D., first author, an archaeologist and a postdoctoral fellow in FAU’s Department of Electrical Engineering and Computer Science.

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,” says John Lindo, Ph.D., a co-corresponding author of the article who specializes in ancient DNA analysis and is an assistant professor in the Department of Anthropology at Emory University. “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.”

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.

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.

“This groundbreaking research involved many different fields from archaeology to biological sciences to genomics and data science,” said Stella Batalama, Ph.D., dean, FAU College of Engineering and Computer 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.”

Study co-authors are Amanda Owings, Ph.D., Emory University; Henry Socrates Lavalle Sullasi, Ph.D., Federal University of Pernambuco, Brazil; and Omer Gokcumen, Ph.D., State University New York at Buffalo. 

This research was supported by the National Science Foundation, National Institutes of Health, and the Fundação de Amparo à Ciência e Tecnologia de Pernambuco. 

- FAU -

CAPTION

The figure depicts the deep ancestries of the ancient individuals of the Americas and archaic ancestry in ancient South America and Panama. The pie chart radius reflects the proportion of shared archaic ancestry in the individual.

CREDIT

Florida Atlantic University

CAPTION

Researchers used teeth from ancient samples collected in archeological sites in northeast Brazil. Teeth are especially important in ancient DNA analysis because of the excellent preservation of biomaterials within the tooth.

CREDIT

Laboratório de Arqueologia Biológica e Forense, Universidade Federal de Pernambuco

CAPTION

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

CREDIT

Henry Lavalle, Universidade Federal de Pernambuco and Ana Nascimento, Universidade Federal Rural de Pernambuco

About FAU’s College of Engineering and Computer Science:

The FAU College of Engineering and Computer Science is internationally recognized for cutting edge research and education in the areas of computer science and artificial intelligence (AI), computer engineering, electrical engineering, biomedical engineering, civil, environmental and geomatics engineering, mechanical engineering, and ocean engineering. Research conducted by the faculty and their teams expose students to technology innovations that push the current state-of-the art of the disciplines. The College research efforts are supported by the National Science Foundation (NSF), the National Institutes of Health (NIH), the Department of Defense (DOD), the Department of Transportation (DOT), the Department of Education (DOEd), the State of Florida, and industry. The FAU College of Engineering and Computer Science offers degrees with a modern twist that bear specializations in areas of national priority such as AI, cybersecurity, internet-of-things, transportation and supply chain management, and data science. New degree programs include Master of Science in AI (first in Florida), Master of Science and Bachelor in Data Science and Analytics, and the new Professional Master of Science and Ph.D. in computer science for working professionals. For more information about the College, please visit eng.fau.edu. 

 

About Florida Atlantic University:
Florida Atlantic University, established in 1961, officially opened its doors in 1964 as the fifth public university in Florida. Today, the University serves more than 30,000 undergraduate and graduate students across six campuses located along the southeast Florida coast. In recent years, the University has doubled its research expenditures and outpaced its peers in student achievement rates. Through the coexistence of access and excellence, FAU embodies an innovative model where traditional achievement gaps vanish. FAU is designated a Hispanic-serving institution, ranked as a top public university by U.S. News & World Report and a High Research Activity institution by the Carnegie Foundation for the Advancement of Teaching. For more information, visit www.fau.edu.

 

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JOURNAL

Proceedings of the Royal Society B Biological Sciences

METHOD OF RESEARCH

Computational simulation/modeling

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Genomic evidence for ancient human migration routes along South America's Atlantic coast

ARTICLE PUBLICATION DATE

1-Nov-2022