University of South Carolina archaeologist Christopher R. Moore used modern forensic techniques to shed light on one of the most enduring questions about prehistoric North America: Were ice age humans responsible for the extinction of large animals, such as mammoths and giant bears? Moore describes his recently published study that examined 120 Clovis spear points and tools and found traces of blood proteins of some animals that lived 13,000 years ago. The research doesn’t provide a definitive answer on whether people, changes in the climate or other factors caused their demise, but “it proves that these animals were present in the Carolinas, and they were hunted or scavenged by early Paleo-Americans,” he writes.

Last fall, editors at The Conversation developed a new article type known as Uncommon Courses, which highlights unusual classes taught by our academic writers. The latest installment in this occasional series was written by Western Illinois University anthropology professor Heather McIlvaine-Newsad, who developed a class called “From Magic Mushrooms to Big Pharma” that delves into nature-based medicine use and associated social issues. Her article touches on a range of traditional medicines, including naturally occurring psychedelics and substances such as turmeric and ginger that have been used to treat inflammation.

Other stories our editors uncovered this week include a piece describing expected disruptions from El Niño this year, a look at how colonialism influences plant collections and biodiversity research and a study examining the factors behind why Americans have higher excess death rates than similar high-income countries.

Also in this week’s science news:

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Animals that shared the landscape with humans disappeared as the ice age ended. Mauricio Antón/Wikimedia Commons

Forensic evidence suggests Paleo-Americans hunted mastodons, mammoths and other megafauna in eastern North America 13,000 years ago

Christopher R. Moore, University of South Carolina

A forensic technique more often used at modern crime scenes identified blood residue from large extinct animals on spearpoints and stone tools used by people who lived in the Carolinas millennia ago.

People for millennia have used what grows around them as medicine. LorenzoT81/iStock via Getty Images Plus

‘From Magic Mushrooms to Big Pharma’ – a college course explores nature’s medicine cabinet and different ways of healing

Heather McIlvaine-Newsad, Western Illinois University

An anthropology course explores how peoples and cultures around the world use nature-based medicines to heal.

For Drosophila melanogaster, their senses have a significant effect on how quickly they age. nico_blue/E+ via Getty Images

Seeing dead fruit flies is bad for the health of fruit flies – and neuroscientists have identified the exact brain cells responsible

Christi Gendron, University of Michigan

When fruit flies see other dead fruit flies, their life spans are cut short. Other species also undergo analogous physiological changes when seeing their dead.

Inside the black box of Amazon returns

Simone Peinkofer, Michigan State University

Returns are becoming a costly sustainability problem for retailers and the planet. A supply chain expert explains.

Are you part robot? A linguistic anthropologist explains how humans are like ChatGPT – both recycle language

Brendan H. O'Connor, Arizona State University

We humans like to think that our language is original, but we absorb large amounts of it from others and liberally repeat and remix what we hear – just as language AIs do.

El Niño is back – that’s good news or bad news, depending on where you live

Bob Leamon, University of Maryland, Baltimore County

The official forecast calls for a strong El Niño by winter, but other models suggest it might dip in and out. An atmospheric scientist explains.

WHO’s recommendation against the use of artificial sweeteners for weight loss leaves many questions unanswered

Lindsey Schier, USC Dornsife College of Letters, Arts and Sciences; Scott Kanoski, USC Dornsife College of Letters, Arts and Sciences

The WHO report concluded that habitual use of nonsugar sweeteners is linked to a modest increase in diabetes, hypertension and stroke. But the research it’s based on has limitations.

Wildfire smoke and dirty air are also climate change problems: Solutions for a world on fire

Drew Shindell, Duke University

So much pollution goes into the air today that even without wildfire smoke, 99% of the global population breathes unhealthy air.

Anti-trans bills and political climates are taking a significant mental health toll on trans and nonbinary people – even during Pride

Jae A. Puckett, Michigan State University

The rainbow Pride flags flying this month obscure the ongoing legislative attacks threatening the health and well-being of transgender and nonbinary people and their families.