Connect with us

Science

Humans Have Been Perfecting Avocados for 7,500 Years

Published

on

Humans Have Been Perfecting Avocados for 7,500 Years

Avocados are true superfoods: dense, buttery scoops of vitamins, fat and fiber, all in a hand-size package.

We worked for a long time to make them this way. According to a paper published Monday in the Proceedings of the National Academy of Sciences, people in what we today call Honduras made avocados a part of their diets at least 10,000 years ago and purposefully improved them starting more than 7,500 years ago — first by managing wild trees, and then by selectively planting new ones, to encourage thicker rinds and larger fruit.

This means fruit domestication at this site began thousands of years before the arrival of more commonly studied plants like maize.

“People were domesticating and cultivating their forests” long before they were planting crops in fields, said Amber VanDerwarker, a professor of anthropology at the University of California, Santa Barbara and an author of the paper.

Avocados first arose in central Mexico about 400,000 years ago. They were originally dispersed by megafauna: Giant ground sloths, elephantine gompotheres and burly toxodons all regularly gulped them down, choking-hazard-size pits and all. By the end of the Pleistocene epoch, around 13,000 years ago, megafauna had spread the oily fruits throughout Central and northern South America, and helped them diversify into at least three different species.

Advertisement

But the mass megafaunal extinction that ended the Pleistocene left the avocados stranded: Without animals big enough to eat them whole and spread their seeds, their range began to shrink. At this point, “humans stepped in,” said Doug Kennett, a professor of environmental archaeology also at the University of California, Santa Barbara and an author of the paper. These humans — who, without the megafauna, now needed new food sources — began cultivating the fruit, “saving avocados,” Dr. Kennett said.

For the new study, researchers focused on a site in western Honduras called El Gigante, an elevated cave that people began frequenting 11,000 years ago. Over generations of living and working there, humans left heaps of discarded squash seeds, maize kernels, agave leaves and much more. Archaeologists have been sifting through it all for about 20 years.

To learn about how people at El Gigante enjoyed avocados, researchers looked at dozens of their seeds found in this “long-term trash pile,” as well as thousands of rind fragments, Dr. VanDerwarker said. They used radiocarbon dating to put these scraps in chronological order, and measured the thicknesses of the rinds and the dimensions of the seeds.

Comparing seed and rind sizes over time allowed the team to trace how humans shaped the fruit. Early on, people were “just picking wild fruits from their trees as they need to,” and the trash was littered with cherry-size seeds and thin bits of rind, Dr. VanDerwarker said.

In layers from about 7,500 years ago, the seeds had become larger and the rinds more robust. This suggests that people were managing existing trees, pruning some branches and new fruits in order to encourage the remaining ones to grow bigger.

Advertisement

In layers from 4,500 years ago, seeds had reached apricot size and rind thickness had pushed beyond the plant’s natural variation — “an indicator that people had started saving seeds and planting their own trees,” Dr. VanDerwarker said. The arborculturalists favored large fruits, as well as hefty skins that helped with preservation and transport.

The study gives “new evidence for 10,000 years plus, probably, of avocado use,” said Tom Dillehay, a research professor at Vanderbilt University who was not involved with this particular study. He said he had found similar signs of longstanding avocado enjoyment in northern Peru; other evidence has been found in Mexico, Colombia and Panama. Dr. Dillehay predicts that as research continues, more sites, and more types of manipulated food plants, will be discovered.

The finding also continues an ongoing shake-up of the notion that food domestication began with animals and cereal grains. That early avocado growers were putting so much effort into their plants is “different than what was imagined even 10 or 15 years ago,” Dr. Kennett said.

While our concepts of plant husbandry come and go, some things are more timeless. One reason to want to cultivate a thick avocado rind is for ease of scooping, said Dr. VanDerwarker, inspiring other tasty imaginings: “I think people have probably been eating guacamole now for a good 10,000 years.”

Advertisement

Science

Forest Service completed prescribed burns on 127,000 acres during shutdown, despite reduced workforce

Published

on

Forest Service completed prescribed burns on 127,000 acres during shutdown, despite reduced workforce

During the government shutdown, the U.S. Forest Service completed prescribed burns on more than 127,000 acres, Forest Service Chief Tom Schultz announced in an internal memo welcoming back furloughed employees. During the same time frame in 2023 and 2024, the Forest Service completed a comparable amount of work, indicating the agency managed to take advantage of prime weather for burns even with a reduced workforce.

“Despite the disruption, we accomplished a great deal together,” the memo, first reported by the Hotshot Wake Up and verified by The Times, said. “We advanced timber sales that strengthen local economies, kept recreation sites open and safe for public enjoyment, and carried out critical wildfire response and active management work.”

By comparison, the Forest Service completed about 200,000 acres of prescribed burns in 2023 from Oct. 1 through Nov. 12 — the same span as the 2025 shutdown — and in 2024, it burned roughly 90,000 acres during that time frame, according to a Forest Service database that tracks hazardous fuel treatment work.

The latest contingency plan for the Forest Service — the largest federal firefighting entity in the country — called for continuing essential work during a shutdown, including responding to and suppressing wildfires.

Advertisement

The plan also involves furloughing roughly 30% of the service’s workforce, including those who oversee forest-use permit processing and public recreation, as well as researchers studying forest health and the timber market. Yet fuel treatment work, such as prescribed burning and mechanically thinning forests, is conducted by many of the same personnel responsible for putting out fires — the part of the workforce that avoided the furloughs.

That was important, given that significant fire activity across the West in 2024 inhibited the Forest Service from reducing wildfire risk on as many acres. So, this year, the Forest Service has been playing catch-up.

However, Grassroots Wildland Firefighters, a nonprofit representing current and former federal firefighters, found in October that Forest Service fuel management work in 2025 was down by 38% compared with recent years. The organization said that downturn was largely due to staff and resource cuts championed by President Trump’s cost-cutting team at the start of his second administration.

The Forest Service did not immediately respond to a request for comment.

California Gov. Gavin Newsom has challenged the federal government to match state investments in wildfire risk reduction work, and in July even sent the White House a draft executive order that Newsom said would accomplish exactly that.

Advertisement

In 2021, the state and U.S. Forest Service agreed to ramp up their yearly fuel treatment work in California to 500,000 acres each by 2025.

In 2023, the most recent year both state and federal data are available, the state reached 415,000 acres, and the Forest Service reached 311,000, according to a state dashboard. From 2021 to 2024, the state invested $4.3 billion to complete that work, whereas the Forest Service invested $3.1 billion.

This past weekend’s rain could mark an early start to prescribed-burn season in Southern California — home to a handful of national forests, including the Los Angeles and San Bernardino forests — as federal employees return to work until at least the end of January, when the agreed-upon funding is set to expire.

“I’m profoundly grateful to welcome our furloughed employees back as the government reopens,” Schultz said in the memo. “I look forward to getting the entire team back together to continue and build upon the work that we’ve begun this new fiscal year.”

Advertisement
Continue Reading

Science

CDC warns of dramatic rise in dangerous drug-resistant bacteria. How you can protect yourself

Published

on

CDC warns of dramatic rise in dangerous drug-resistant bacteria. How you can protect yourself

Infection rates are soaring in the United States due to a menacing bacteria that are resistant “to some of the strongest antibiotics available,” prompting infectious-disease experts to warn about the difficulty of responding to the surge.

The Centers for Disease Control and Prevention warned in a report this week that between 2019 and 2023, bacterial infections caused by a “super bug” bacteria dubbed NDM-producing carbapenem-resistant Enterobacterales (NDM-CRE) surged by more than 460% in the U.S.

The NDM-CRE is a type of bacteria with a special gene that can break down powerful antibiotics rendering most drug treatments ineffective, said Shruti Gohil, associate professor of infectious diseases at UC Irvine School of Medicine.

“This makes these ‘superbug’ bacteria very hard to treat because they’re resistant to some of the strongest antibiotics we have,” Gohil said.

The CDC’s findings, originally published in a 2022 report, noted that there were approximately 12,700 infections and 1,100 deaths in the U.S. in 2020 due to this drug-resistant bacteria.

Advertisement

The public health agency did not determine the exact reason for the surge; however, there is an association involving the use of antibiotics to treat COVID-19 patients in the beginning of the pandemic, said Neha Nanda, medical director of antimicrobial stewardship with USC’s Keck Medicine.

Public health officials warn that NDM-CRE has not historically been common in the U.S., so healthcare providers might not suspect it when treating patients with bacteria-related infections.

The rise of the bacteria also “threatens to increase NDM-CRE-related infections and deaths,” according to the CDC.

This is the second report the CDC released that highlighted a rise in bacteria-related cases, the most recent was published in June and focused on cases in New York City between 2019 and 2024.

Available treatment for NDM-CRE?

Experts say people with NDM-CRE bacteria won’t have any symptoms unless they develop an infection. Once they develop an infection, the symptoms will vary. NDM-CRE can cause such ailments as pneumonia, bloodstream infections, urinary tract infections and wound infections.

Advertisement

Some symptoms can include fever, chills with cough, shortness of breath if the bacteria infect the lung, and pain or blood when urinating if the bladder/kidneys are infected.

Since the bacteria are resistant to most antibiotics, treatment options are severely limited, leading to slower recovery and higher risk of serious complications or death, Gohil said.

Another reason health officials are concerned is because the bacteria can spread to others and survive on contaminated surfaces.

Doctors can test for NDM-CRE, but most people do not need to be tested unless they are at higher risk for having it, according to experts.

Those at risk are people who have been “in a hospital (especially in another country), had repeated antibiotics, hospital stays, or invasive medical procedures, or if you’re sick and been in contact with someone known to have NDM-CRE,” Gohil said.

Advertisement

Testing for the bacteria is also difficult because many hospitals and clinics do not have the tools to rapidly detect it in patients even when the patient is not sick.

How to protect yourself against NDM-CRE

NDM-CRE is caused by overuse of powerful antibiotics.

“I think this may be an opportunity for us to change the narrative where all patients typically want antibiotics,” Nanda said.

Nanda advises patients who are being prescribed with antibiotics to ask their healthcare provider:

  • Why they’re getting prescribed the antibiotics? Why is it necessary?
  • Ask about your options. Make sure you’ve exhausted all other treatments options before going straight to antibiotics.

“If you need it, you need it, but then be judicious about it,” she said.

Because NDM-CRE infections happen to people who are very sick, patients in hospitals or in long-term care, experts recommend that patients, healthcare staff and visitors in these settings wash their hands and avoid contact with dirty surfaces.

Advertisement
Continue Reading

Science

Trump says research links Tylenol and autism; scientists say their paper is being misinterpreted

Published

on

Trump says research links Tylenol and autism; scientists say their paper is being misinterpreted

During this week’s White House press conference in which President Trump named the over-the-counter drug Tylenol as a possible cause of rising autism rates, he did not mince words, urging pregnant women to “fight like hell” not to take it.

But outside those remarks in the Roosevelt Room — during which Trump himself acknowledged “I’m not so careful with what I say” — the discussion on the common fever and pain reliever’s role during pregnancy is a lot more nuanced.

What the research on Tylenol use during pregnancy actually says

Physicians, researchers on the very studies cited in support of Trump’s position and even other members of the president’s administration are largely united on a few key facts: untreated fevers in pregnancy pose real risks to the fetus, acetaminophen (Tylenol’s active ingredient) remains the safest medication to treat them and any pregnant person seeking advice on the issue should consult their doctor.

“All that we should be asking of the medical profession [is] to actually weigh the risks and benefits for the women, with the women, and be cautious about chronic use of pain medications,” said Dr. Beate Ritz, a UCLA professor of epidemiology who co-authored a paper published last month that the White House cited as evidence for the link between Tylenol and autism.

Ritz said it has been misinterpreted.

Advertisement

The conclusion of the paper, which reviewed existing studies on the topic, was that the association between acetaminophen use in pregnancy and later diagnoses of neurodevelopmental disorders in kids was strong enough to merit doctors’ consideration when determining how to treat fever or pain in pregnancy. The group did not determine a causal relationship between the drug and autism, or suggest barring the drug altogether, she said.

“Looking at all of these studies, yes, there is a risk,” Ritz said. “It’s not very big, but it’s there, but the risk increases are more seen in regular users of Tylenol. This is not a woman who has a fever and takes three Tylenols.”

“There is always a weighing of the risks and the benefits, and fever in women is no good either. … Not having to take any pain medications when you are in severe pain or in chronic pain is also very cruel,” she said. “We all should have an interest in helping out here, making the right decisions without blaming the victim and putting it all on the individual woman.”

Her co-author, University of Massachusetts epidemiologist Ann Bauer, has made similar statements.

“What we recommend is judicious use — the lowest effective dose [for] the shortest duration of time under medical guidance and supervision, tailored to the individual,” Bauer told the news outlet Politico.

Advertisement

The administration’s confusing recommendations

Ultimately, that’s what the administration is recommending as well.

The letter that U.S. Food and Drug Administrator Dr. Marty Makary sent to physicians this week made clear that “a causal relationship” between autism and acetaminophen “has not been established and there are contrary studies in the scientific literature.”

It went on to recommend that clinicians consider limiting their use of acetaminophen for routine low-grade fevers during pregnancy, while noting that medical advice “should also be balanced with the fact that acetaminophen is the safest over-the-counter alternative in pregnancy among all analgesics and antipyretics.” (An analgesic is a pain reliever; an antipyretic reduces fever.)

Untreated fevers during pregnancy are associated with higher rates of birth defects, particularly those of the heart, brain and spinal cord; premature birth; low birth weight; neurodevelopmental disorders including autism; and fetal death, said Dr. E. Nicole Teal, an assistant professor of maternal-fetal medicine at UC San Diego.

“The FDA’s letter, while significantly more nuanced than the president’s comments on the issue, still gives too much weight to findings from poorly designed studies,” she said.

Advertisement

She said she will continue to prescribe acetaminophen to pregnant patients who need to treat fevers or severe pain, as it has the fewest known risks in pregnancy.

Are there other pain-relief and fever-reducing drugs that can be used during pregnancy?

Nonsteroidal anti-inflammatory drugs like ibuprofen (often sold as Advil) or naproxen (often sold as Aleve) are linked to problems with blood vessel and kidney development, as well as oligohydramnios, a condition in which there isn’t enough amniotic fluid to support a healthy pregnancy. Aspirin raises the risk of bleeding complications, and narcotics — which can relieve pain but not fever — pose addiction risks for the mother and infant alike, Teal said.

She referred to a statement from the American College of Obstetricians and Gynecologists noting that two decades of research on the question had failed to find a causal relationship between acetaminophen and autism.

“Acetaminophen is one of the few options available to pregnant patients to treat pain and fever, which can be harmful to pregnant people when left untreated,” American College of Obstetricians and Gynecologists president Dr. Steven J. Fleischman said in the statement.

The group also noted that reviews in 2015 and 2017 from the FDA and the Society for Maternal-Fetal Medicine respectively found no risks associated with appropriate usage of the drug in pregnancy.

Advertisement

How to navigate government communications around Tylenol use

Nonetheless, the mixed messaging from the Trump administration about Tylenol seems likely to continue.

The Department of Health and Human Services this week reposted a 2017 tweet from the Tylenol brand’s account that said, “We actually don’t recommend using any of our products while pregnant.”

A spokesperson for Kenvue, the company that owns Tylenol, said the post was taken out of context and incomplete.

“Consistent with regulations, our label states clearly ‘if pregnant or breast-feeding, ask a health professional before use,’ ” Melissa Witt said in an email. “We do not make recommendations on taking any medications in pregnancy because that is the job of a healthcare provider.”

Vice President JD Vance offered similar guidance this week.

Advertisement

“My guidance to pregnant women would be very simple, which is follow your doctor. Right?” Vance said in an interview with the outlet NewsNation after Trump’s press conference. “Talk to your doctor about these things.”

Continue Reading
Advertisement

Trending