Why Florida’s plan to end vaccine mandates will likely spread to other conservative states

Source: The Conversation – USA (2) – By Anindya Kundu, Assistant Professor of Educational Leadership, Florida International University

Florida has been a leader for other conservative states on education reform. iStock/Getty Images Plus

Florida Gov. Ron DeSantis announced a plan in early September 2025 that he intends to make Florida the first state to end vaccine mandates across all schools and in other state-run institutions such as nursing homes.

His proposal would dismantle Florida Statute 1003.22, which requires that all schools, including public and private schools, collect proof of students’ immunization for a range of communicable diseases when they enroll.

In 2025, approximately 88.7% of Florida kindergartners are vaccinated, which is almost 5% lower than the national average. Florida’s rate of vaccination for kindergarten students has steadily declined over the past eight years – and dropped from 93.5% in 2020 to 89.9% in 2024.

If Florida state legislators approve DeSantis’ plan when they convene in January 2026, the state would sweepingly eliminate long-standing obligations for schools and other places to require a standard set of immunizations for enrollment. Florida nursing homes currently assess whether residents should receive pneumococcal and flu vaccines.

As a sociologist, I study how education policy shapes democracy, social cohesion and inequality. I am also a professor of educational policy studies.

DeSantis’ plan is indicative of Florida’s general approach to approve education policy that is aligned with conservative priorities on “woke politics” and culture war issues, such as book bans.

Other Republican-led states, such as Alabama, Arkansas and Iowa, are typically quick to follow Florida’s lead and implement their own versions of Florida’s educational and social policies.

A white man with dark hair wears a navy blue suit and stands at a podium that says 'Florida, the education state.'
Florida Gov. Ron DeSantis speaks after he signed three education bills in Sarasota, Fla., in May 2023.
Thomas Simonetti for The Washington Post via Getty Images

Florida setting examples

Well before DeSantis, Florida has tried to be a national leader of educational reform and has tightened state control over schools by reshaping standards on testing, school curricula and guidance on what can and cannot be taught in public schools.

Florida’s former Gov. Jeb Bush, who served from 1999 through 2007, helped lead this educational reform work. He was steadfast in increasing top-down accountability for educators, closely monitoring their performance by increasing high-stakes testing and tying teachers’ compensation to test results.

Bush also widely promoted policies to expand school choice for parents or policies that often allow any parent – regardless of income – to apply for state grants that use public money to pay for their children’s private school education.

Public school enrollment has steadily declined in Florida over the past two decades. While 86% of Florida students attended a traditional public school in 2001-2002, just 51% of Florida children went to a public school in 2024.

In 2022, Arizona became the first state to adopt a universal voucher system.

Florida then expanded its school voucher program in 2023 – allowing all parents, regardless of income, to use state taxpayer-funded scholarships to help pay for their children’s private school or home school experience. More than 500,000 Florida students received these vouchers in 2025.

Since 2024, 10 states plus Washington D.C. have adopted voucher programs.

Critical race theory on the front line

Since taking office in 2018, DeSantis has also set his sights squarely upon other hot-button issues, including by banning critical race theory from public schools in 2021.

Critical race theory, or CRT, is an academic framework that looks at how different forms of marginalization, such as gender or race, overlap, as well as how racism is embedded within American institutional and legal structures. DeSantis has said that CRT amounts to “state-sanctioned racism” that teaches “kids to hate our country or to hate each other.”

I and other experts on education considered this ban on CRT largely symbolic. The likelihood that K-12 educators are trained in CRT to then teach it to students seemed remote.

That same year, Florida rejected 54 math textbooks that officials felt contained CRT-related subject matter.

In 2023, DeSantis also cited CRT when he blocked Florida from offering the nonprofit College Board’s newly developed AP African American Studies course from public schools.

These actions made Florida one of the first states to place formal policy restrictions on CRT, effectively prohibiting discussions around race and inequality in public schools.

Since 2021, 44 other states have introduced similar bills. Approximately 28 states, including Texas, Idaho, Tennessee and Montana, have adopted at least one law limiting educators’ discussions of racism and sexism.

Anti-LGBTQ+ measures

In 2022, Florida also became the first state to prohibit classroom instruction on sexuality or gender identity topics from kindergarten through third grade. This law – formally called the Parental Rights in Education Act but often referred to as “Don’t Say Gay” – also restricts discussion on these topics in higher grades.

Though the law restricts formal classroom discussion or curriculum on sexuality and gender identity, teachers are allowed to discuss these topics in informal settings, such as student gay and straight alliance clubs.

By 2024, a growing list of at least 20 states, including Alabama and Indiana, followed Florida and introduced similar laws to “Don’t Say Gay.”

A woman wears a light-colored shirt and holds a door handle of a building that has painted words on its light wall: 'Censorship leaves us in the dark.'
A bookstore in Coral Gables, Fla., shows a list of banned books in 2022.
Jeffrey Greenberg/UCG/Universal Images Group via Getty Images

Book bans

Book bans are another prominent front where DeSantis has influenced how education looks in Florida – and in other states.

Book bans refer to schools and libraries removing books that are deemed controversial or inappropriate for students, often flagged for content related to race, sexuality or gender.

In 2023, Florida passed a law called HB 1069, which, among other things, banned books primarily flagged by parents or education officials for discussing or mentioning sexual topics.

One of these banned books was “Arthur’s Birthday,” a children’s picture book based on the animated PBS children’s series about an aardvark. The book was banned for including a reference to the game “spin the bottle.”

Florida’s schools banned approximately 4,500 books in the 2023-2024 school year, more than any other state.

A federal judge overruled a large portion of HB 1069 in August 2025, calling the categorization overly broad and unconstitutional.

Following Florida’s example, 33 other states passed laws about book bans in the 2022-2023 school year.

Overall, there has been a 200% increase in book bans nationwide from 2022 to 2024.

Beyond Florida

If Florida lifts its vaccine mandate, the decision would also affect other groups in Florida, including young children in day care centers and elderly residents living in nursing homes, which would also no longer require vaccines.

Private schools and universities would retain the ability to impose their own stances and vaccine requirements. However, private educational institutions in Florida often preemptively align themselves with state guidance.

Idaho loosened its vaccination rules in the summer of 2025, prohibiting schools from denying admission to a person who has not received vaccines. Louisiana has also said it will stop promoting mass vaccine campaigns.

As recent education policy history shows, Florida’s potential decision to end vaccine mandates in schools and other places would immediately have ripple effects across the nation. It is likely that if Florida strikes down its school vaccine requirements, this move will catalyze a rapid unraveling of similar public health protections across other states.

The Conversation

Anindya Kundu does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Why Florida’s plan to end vaccine mandates will likely spread to other conservative states – https://theconversation.com/why-floridas-plan-to-end-vaccine-mandates-will-likely-spread-to-other-conservative-states-264734

Soil erosion is tearing DRC cities apart: what’s causing urban gullies, and how to prevent them

Source: The Conversation – Africa – By Matthias Vanmaercke, Associate professor BOF Faculty of Science, KU Leuven

In fast-growing cities like some in the Democratic Republic of Congo (DRC), heavy rains are carving huge scars into the land. Known as urban gullies, these deep erosion channels can swallow homes, destroy roads and displace entire communities.

They can grow to hundreds of metres long and dozens of metres wide, splitting neighbourhoods in two. Once established, they keep expanding with each major downpour.

The consequences are devastating. In Kinshasa, the DRC’s capital, heavy rainfall in December 2022 triggered rapid gully expansion, destroying homes and claiming dozens of lives.

Urban gullies form when rainwater runoff cuts deep channels into fragile soils. The erosive force of concentrated water exceeds the strength of these soils. The gullies usually form after intense rain on steep slopes. Urbanisation makes the situation worse as vegetation is removed to build houses, greatly increasing the likelihood that heavy rainfalls will simply run off the top soil. Roads also play a critical part as they can change how water flows across the landscape, forming direct pathways along which runoff can accumulate.

Our new study reveals the staggering scale of the problem in the DRC. Our research team of Congolese and Belgian earth scientists and geographers identified 2,922 urban gullies in 26 DRC cities.

We used satellite imagery and population data to identify the gullies. Our detailed, nationwide mapping effort – the first to map gully erosion across an entire country – shows that this is not a series of isolated incidents but a widespread and fast-growing hazard.

But urban gullies can be avoided by adequate urban planning and infrastructure. This includes adapted zoning plans and measures such as better road drainage, rainwater retention and infiltration systems, increased vegetation cover and targeted engineering works to divert runoff safely.

The crisis in numbers

Many of the urban gullies in the DRC are huge. A typical example is easily 250 metres long and 30 metres wide. Together, they stretch nearly 740 kilometres.

Kinshasa alone has 868 mapped gullies (221km in total). With about 17 million inhabitants, it is the DRC’s largest city and one of Africa’s megacities, where rapid, unplanned growth (around 6.6% per year) makes gully erosion a major urban hazard. Kinshasa is also tropical with annual rainfall typically above 1,000 millimetres.

By reconstructing how these features expanded between 2004 and 2023, we calculated that 118,600 people in the DRC were forced from their homes. Displacement has accelerated sharply: before 2020, about 4,600 people were displaced annually; today, the figure is more than 12,000.

The study also looked ahead. In 2023, some 3.2 million Congolese lived in areas considered at risk of future gully expansion. Of these, more than half a million are in zones where the chance of losing their homes within a decade is very high.




Read more:
Urban greening in Africa will help to build climate resilience — planners and governments need to work with nature


Several factors make Congo’s cities especially prone to gully erosion. Many are built on steep slopes with sandy soils that are highly erodible. Rapid, unplanned urban growth strips vegetation and increases impermeable surfaces such as rooftops and roads, which funnel runoff into concentrated flows.

The link with roads is particularly striking: 98% of all mapped gullies were connected to the road network, either forming along unpaved streets or fed by runoff from poorly drained roads.

The problem is set to worsen. Congo’s urban population is booming, driven by both natural growth and migration. Informal neighbourhoods often lack basic infrastructure, leaving rainfall to carve its own destructive paths.

Climate change adds another layer of risk. Rainfall intensity in tropical Africa is projected to rise by 10%-15% in the coming decades. Since heavy downpours are a trigger for gully formation, expansion rates could double if no action is taken.

Prevention over cure

Once formed, gullies are extremely hard and costly to stabilise. Local communities often try to slow their advance, but without proper engineering solutions, most efforts fail. Stabilising a single large gully can cost the DRC more than US$1 million, an impossible burden for most municipalities.

The study shows that prevention is the only viable long-term strategy. That means paying careful attention to how cities are planned and built. Measures such as better road drainage, rainwater retention systems and strategic vegetation cover can reduce the risks.




Read more:
Climate change is a threat to Africa’s transport systems: what must be done


Above all, improved spatial planning is crucial to stop new neighbourhoods from being built in vulnerable areas. The effectiveness of specific urban gully control measures remains largely unknown and poorly documented, apart from an earlier case study in the DRC that showed that many measures fail. But such measures should not be confused with better spatial planning. This means avoid constructing houses and roads in areas that are sensitive to urban gully formation, or at least making sure that rainwater is safely stored or evacuated.




Read more:
Kenya’s devastating floods expose decades of poor urban planning and bad land management


We argue that the best strategy for limiting the impacts of urban gullies is preventing them.

Above all, urban gullies must be recognised as a disaster risk on par with floods and landslides. Only then can policies and investments be developed that are needed to protect vulnerable populations.




Read more:
Africa’s refugee camps are plagued by flooding: we looked into drainage systems that can withstand local conditions


A problem in the rest of Africa too

Although the DRC is at the epicentre of the crisis, similar problems are emerging elsewhere in Africa, including Nigeria, Uganda, Burundi and Madagascar.




Read more:
Flooding in Nigeria is on the rise – good forecasts, drains and risk maps are urgently needed


With urban populations across the global south expected to nearly triple by 2050, gully erosion could become one of the defining urban hazards of the century.

The deep scars running through Congo’s cities are not just features of the landscape, they are reminders of the urgent need to rethink how urban growth is managed in vulnerable regions.

The Conversation

Matthias Vanmaercke receives funding from the University of Leuven. The research behind this article was funded through the Belgian ARES research collaboration project PREMITURG (Prevention and Mitigation of Urban Gullies: lessons learned from failures and successes, D.R. Congo)

ref. Soil erosion is tearing DRC cities apart: what’s causing urban gullies, and how to prevent them – https://theconversation.com/soil-erosion-is-tearing-drc-cities-apart-whats-causing-urban-gullies-and-how-to-prevent-them-264497

A cold shock to ease the burn − how brief stress can help your brain reframe a tough workout

Source: The Conversation – USA – By Marcelo Bigliassi, Assistant Professor, Florida International University

When you lift weights, walk up a steep hill or ride a bike, your body is continuously sending sensory signals to your brain. These signals paint a picture of the physical sensation of what you’re doing. Your brain then takes these signals and filters them through your past experience, goals, expectations and current emotional state.

It turns out that the way your brain uses all that context to interpret this sensory information significantly influences whether you perceive something physically strenuous, such as a bike ride, as difficult and threatening or as rewarding and pleasant.

Many people who are new to exercise often quit because they interpret physical discomfort as a warning sign instead of a challenge that can be overcome. But in recent years, scientists have shown that by changing your emotional state, you can also change how you interpret physical sensations.

We are two neuroscientists who study how the brain and body respond to stress and how those reactions shape perception. Research has shown that small, well-timed challenges can help the body and mind grow more resilient, while too much stress, or stress at the wrong time, can slow recovery and sap motivation.

In a recent experiment, we wanted to see whether it is possible, in a sense, to recalibrate how the brain interprets difficult tasks using a tiny, safe dose of physical discomfort. We found that physical stress in manageable doses – in this case, dunking your hand in ice-cold water – can make a later effort feel more doable, particularly for people who are not yet accustomed to strenuous exercise.

man and woman in street clothes show a paper to a woman in exercise gear on stationary bike
Authors Marcelo Bigliassi and Dayanne S. Antonio monitor psychophysiological and psychological data while a participant performs a cycling exercise on a stationary ergometer.
Margi Rentis

Cold first, bike second

In order to evaluate the concept of stress calibration, we assembled a group of 31 adult volunteers with limited prior engagement in physical activity. Our physical fitness task involved volunteers riding a stationary bike for six minutes, with the effort increasing in short stages from easy to tough.

On one visit, before getting on the bike, participants put one hand into a bucket of ice-cold water and kept it there for as long as they could – between one and three minutes. We hypothesized this physical stress would trigger a slight change in how their brains would interpret physical sensations and change their ability to tolerate physical discomfort; this was the recalibration step.

On the other visit they just got on the bike without doing a cold-water hand dunk. To help control for variables, we mixed up the order so that some people did the cold-water dunk on the first day and others did it on the second.

While riding the test bike, participants reported on a number of variables using rating scales, including how much pain they felt, how pleasant or unpleasant the effort seemed, how much energy they had, and whether they felt in control or overwhelmed. These measures allowed us to track how the volunteers were experiencing the exercise at different levels of intensity, both with and without the cold-water hand dunk.

What we found

hand immersed in white bucket filled with water and ice
Participant immerses her hand in a container filled with ice water, in a test commonly used to evaluate stress tolerance and cardiovascular reactivity.
Margi Rentis, CC BY

When we first saw the results, we were amazed by how much a short stress induction could affect people’s perceptual responses during exercise. During the hardest two minutes of the cycling task, the participants who had lasted longer in the cold-water dunk actually reported less pain and more pleasure. Additionally, the participants who said they had a high tolerance for pain experienced a slightly greater sense of dominance compared to other participants as the biking intensity peaked.

We believe three effects may help explain why our participants felt the toughest minutes on the bike were less painful and more enjoyable after the cold-water challenge.

The first effect is similar to a quick biological reset. Ice water jolts the nervous system. In response, the brain switches on its built-in pain-dimming system and sends “turn it down” signals down the spinal cord. For a short window, incoming pain messages are muted, so discomfort feels less intense, helping participants tolerate more pain during cycling right after the hand dunk.

The second effect is a short stress surge. When the body feels stress, your heart rate and blood pressure jump, stress chemicals rise, and the brain may turn pain down for a moment. That bump can make the first minutes of exercise feel less abrupt, almost as if you did a quick psychological warmup. As the surge fades, your system settles, allowing you to find your rhythm without the start feeling so shocking.

The third mechanism works through the brain’s interpretation of the sensations. Getting through the short burst of discomfort from the ice dunk seemed to give participants an instant sense of “I can handle this” and a feeling of accomplishment. We think this boost recalibrates how their brains interpret stress and discomfort.

From lab insight to everyday training

At its core, this study shows that how your brain perceives physical sensations is adjustable. A short, well-timed challenge, such as an ice-cold hand dunk, can act as a calibration mechanism, tilting the toughest moments of exercise away from pain and toward enjoyment.

You don’t need an ice bucket to apply this principle to your life. The challenge could be a short uphill push before a longer run, a quick set of jump squats before starting a workout, or a short jog before a more challenging activity. These brief contrasts can prime the body and mind so the main effort feels less like a threat and more like progress. The key is to keep the challenge short, safe and within your limits, especially on days when life is already stressful.

This finding fascinates us because it shows that neither your brain nor your body is just a passive passenger during effort. They constantly recalibrate what “hard” feels like. The effect of overcoming one small challenge can ripple forward, making the next challenge feel more doable and even rewarding.

Over time, those small wins become reference points, proof that effort leads to recovery and growth. Layered into everyday training, they turn workouts into opportunities to practice composure, restore a sense of control and build lasting resilience.

The Conversation

Marcelo Bigliassi is an Assistant Professor of Psychophysiology and Neuroscience at Florida International University. He receives funding from the National Institutes of Health (NIH), serves on the advisory board of the Antifragile Academy, and works as the Chief Scientist at NeuroMotor Training and NeuroSmart.

Dayanne Antonio is a Ph.D. student at Florida International University and serves as a Teaching Assistant in the undergraduate Kinesiology program. She reports no conflicts of interest.

ref. A cold shock to ease the burn − how brief stress can help your brain reframe a tough workout – https://theconversation.com/a-cold-shock-to-ease-the-burn-how-brief-stress-can-help-your-brain-reframe-a-tough-workout-258552

Scams and frauds: Here are the tactics criminals use on you in the age of AI and cryptocurrencies

Source: The Conversation – USA – By Rahul Telang, Professor of Information Systems, Carnegie Mellon University

Scammers often direct victims to convert cash to untraceable cryptocurrency and send it to them. Joe Raedle/Getty Images

Scams are nothing new – fraud has existed as long as human greed. What changes are the tools.

Scammers thrive on exploiting vulnerable, uninformed users, and they adapt to whatever technologies or trends dominate the moment. In 2025, that means AI, cryptocurrencies and stolen personal data are their weapons of choice.

And, as always, the duty, fear and hope of their targets provide openings. Today, duty often means following instructions from bosses or co-workers, who scammers can impersonate. Fear is that a loved one, who scammers also can impersonate, is in danger. And hope is often for an investment scheme or job opportunity to pay off.

AI-powered scams and deepfakes

Artificial intelligence is no longer niche – it’s cheap, accessible and effective. While businesses use AI for advertising and customer support, scammers exploit the same tools to mimic reality, with disturbing precision.

Deepfake scams use high-tech tools and old-fashioned emotional manipulation.

Criminals are using AI-generated audio or video to impersonate CEOs, managers or even family members in distress. Employees have been tricked into transferring money or leaking sensitive data. Over 105,000 such deepfake attacks were recorded in the U.S. in 2024, costing more than US$200 million in the first quarter of 2025 alone. Victims often cannot distinguish synthetic voices or faces from real ones.

Fraudsters are also using emotional manipulation. The scammers make phone calls or send convincing AI-written texts posing as relatives or friends in distress. Elderly victims in particular fall prey when they believe a grandchild or other family member is in urgent trouble. The Federal Trade Commission has outlined how scammers use fake emergencies to pose as relatives.

Cryptocurrency scams

Crypto remains the Wild West of finance — fast, unregulated and ripe for exploitation.

Pump-and-dump scammers artificially inflate the price of a cryptocurrency through hype on social media to lure investors with promises of huge returns – the pump – and then sell off their holdings – the dump – leaving victims with worthless tokens.

Pig butchering is a hybrid of romance scams and crypto fraud. Scammers build trust over weeks or months before persuading victims to invest in fake crypto platforms. Once the scammers have extracted enough money from the victim, they vanish.

Pig-butchering scams lure people into fake online relationships, often with devastating consequences.

Scammers also use cryptocurrencies as a means of extracting money from people in impersonation scams and other forms of fraud. For example, scammers direct victims to bitcoin ATMs to deposit large sums of cash and convert it to the untraceable cryptocurrency as payment for fictitious fines.

Phishing, smishing, tech support and jobs

Old scams don’t die; they evolve.

Phishing and smishing have been around for years. Victims are tricked into clicking links in emails or text messages, leading to malware downloads, credential theft or ransomware attacks. AI has made these lures eerily realistic, mimicking corporate tone, grammar and even video content.

Tech support scams often start with pop-ups on computer screens that warn of viruses or identity theft, urging users to call a number. Sometimes they begin with a direct cold call to the victim. Once the victim is on a call with the fake tech support, the scammers convince victims to grant remote access to their supposedly compromised computers. Once inside, scammers install malware, steal data, demand payment or all three.

Fake websites and listings are another current type of scam. Fraudulent sites impersonating universities or ticket sellers trick victims into paying for fake admissions, concerts or goods.

One example is when a website for “Southeastern Michigan University” came online and started offering details about admission. There is no such university. Eastern Michigan University filed a complaint that Southeastern Michigan University was copying its website and defrauding unsuspecting victims.

The rise of remote and gig work has opened new fraud avenues.

Victims are offered fake jobs with promises of high pay and flexible hours. In reality, scammers extract “placement fees” or harvest sensitive personal data such as Social Security numbers and bank details, which are later used for identity theft.

How you can protect yourself

Technology has changed, but the basic principles remain the same: Never click on suspicious links or download attachments from unknown senders, and enter personal information only if you are sure that the website is legitimate. Avoid using third-party apps or links. Legitimate businesses have apps or real websites of their own.

Enable two-factor authentication wherever possible. It provides security against stolen passwords. Keep software updated to patch security holes. Most software allows for automatic update or warns about applying a patch.

Remember that a legitimate business will never ask for personal information or a money transfer. Such requests are a red flag.

Relationships are a trickier matter. The state of California provides details on how people can avoid being victims of pig butchering.

Technology has supercharged age-old fraud. AI makes deception virtually indistinguishable from reality, crypto enables anonymous theft, and the remote-work era expands opportunities to trick people. The constant: Scammers prey on trust, urgency and ignorance. Awareness and skepticism remain your best defense.

The Conversation

Rahul Telang does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Scams and frauds: Here are the tactics criminals use on you in the age of AI and cryptocurrencies – https://theconversation.com/scams-and-frauds-here-are-the-tactics-criminals-use-on-you-in-the-age-of-ai-and-cryptocurrencies-264867

For birds, flocks promise safety – especially if you’re faster than your neighbor

Source: The Conversation – USA (2) – By Joan Strassmann, Professor of Biology, Washington University in St. Louis

Sanderlings run in groups as they hunt for food in the sand on Long Beach Island, N.J. Vicki Jauron, Babylon and Beyond Photography/Moment via Getty Images

As I walked along Bolivar Flats, just across from Galveston Island in Texas, I watched flocks of sanderlings forage along the frothy wavefront as it surged and retreated. Nearby, Caspian terns, American avocets, and black skimmers rested on the beach, each in its own group.

The birds rose simultaneously as I drew near, and then settled farther down the beach, clearly fearing me.

As an evolutionary biologist and author of the new book “The Social Lives of Birds,” I’m fascinated by how social behavior has evolved in birds. Why is it ever worth being with others that not only compete for food but may pass on diseases or even mate with your partner?

A tern with a bright orange beak carries a small fish as tiny tern chick eats parts of it. Another tern keeps a tiny tern chick warm.
A pair of Caspian terns, with other terns around them, feed their chicks on a beach.
US Environmental Protection Agency

Safety in numbers

The late Oxford University biologist William D. Hamilton discussed the advantages of flocking with his landmark 1971 paper “Geometry for the Selfish Herd.” He theorized that individuals in a flock stay because each benefits from the shelter of the group. At the time, a prevailing belief was that animals moved in groups for the benefit of the group, not the individual.

Groups provide some safety because they’re harder to attack, they’re more likely to provide warnings of approaching danger, and they have an ability to respond together if threatened.

But everyone in the group does not necessarily benefit equally.

A flock of seagulls takes off as a child runs down a beach into the group.
When a threat approaches, a bird in a flock is harder to target.
Ed Schipul via Wikimedia Commons, CC BY-SA

The best position is one that puts another bird between oneself and a predator, making your neighbor the more likely target. This keeps birds in a group close together as each tries for living shelter. It is a kind of movement you’ll also see in schools of fish or great herds of ungulates in Africa, like wildebeests.

The peril of being the lone bird

Shorebirds, similar to those I saw in Texas, might be the easiest to study, particularly where the predator can come from a forest that borders the shore.

One of the best-studied flocking shorebirds is the common redshank, Tringa tetanus, often seen feeding on mudflats and saltmarshes in Britain. Redshanks are sandpipers very closely related to the greater and lesser yellowlegs I see in Texas, but with red legs rather than yellow.

Two small birds on a rock with red legs that appear long for their small bodies.
Two noisy redshanks in the Shetland Islands.
Mike Pennington via Wikimedia, CC BY

The predator that redshanks have most reason to fear is the Eurasian sparrowhawk, which watches foraging redshanks from the trees bordering the saltmarsh. When a sparrowhawk picks its prey, it flies fast and hard toward a single predetermined target, grabbing the hapless redshank with its talons.

Evolutionary biologist Will Cresswell studied the redshank’s flocking behavior on the chilly Tyninghame Estuary and found that sparrowhawks were most successful in catching lone birds and those in smaller flocks.

A hawk carries a smaller bird in its talons as it flies.
Why shorebirds have reason to fear Eurasian sparrowhawks and look for safety in numbers.
Janne Passi via Wikimedia, CC BY-SA

The closer a bird was to a neighbor, the less likely it was to be targeted and caught. That reminds me of that old trope about how fast you have to run from a lion: just faster than your neighbor.

Large flocks have downsides, too

One downside to being in a large redshank flock is that these birds have to take more steps to get food because they have more competition.

With other flock members probing the sand, and the sand shrimp and other invertebrates fleeing this probing, the redshanks spend more time foraging when they are in larger flocks.

More than a dozen red birds flutter around a backyard bird feeder trying to get close enough to grab some seeds.
A flock of purple finches competes for space at a feeder. While flocks provide safety, they also mean more competition for food.
ImagePerson via Wikimedia Commons, CC BY

Canadian ornithologist Guy Beauchamp compared closely related species on islands where there were fewer predators with those on the mainland where predators were common. Flocks were smaller on islands, allowing the birds to forage with less competition.

Fantastic flying flocks

Flying in flocks can also help birds avoid predators.

Evolutionary biologist Daniel Sankey and his colleagues separated the behavior of predator and prey by using an artificial predator, the ingeniously engineered flying robot falcon. Its behavior could be mechanically controlled as it approached a flock of homing pigeons, all labeled with GPS tags that allowed precise measurements of how the birds’ positions changed.

The team compared pigeon flight with and without attacks by the robot falcon and found that when the pigeons noticed the robot falcon, they turned sharply away from it, following the direction their nearest neighbor was turning and did not cluster more tightly.

A murmuration of starlings in flight. National Geographic.

More spectacular but harder to study are the mesmerizing flocks of European starlings as they circle and swerve, avoiding predators before settling for the night. These flocks of thousands are called murmurations and are fantastic to watch, and likely frustrating for predators that would struggle to grab a single bird from the swirling scene.

Italian physicist Michele Ballerini figured out that this magnificent visual concert was the result of birds simply keeping track of six nearest neighbors, turning and moving when they did.

Beyond flocks: Roosts and supersociality

Birds are social in other ways, too.

Some sleep together in roosts, nest near each other in colonies, or show off together, carrying out mating dances in what is known as lekking to attract females. They may actively help each other in rearing the young, typically if they are related to the breeders, or anticipate inheriting the breeding position or territory.

Male sage grouse strut their stuff during lekking. National Geographic.

Take time to watch the behavior of the birds around you, and you’ll start to notice social behaviors everywhere, from the ducks in a city pond to the chickadees hunting for insects deep in winter. I hope you’ll watch them with more understanding of their social lives, and with a little bit more wonder.

The Conversation

I wrote a book, The Social Lives of Birds, and this piece might increase sales of this book since it is about the same topic and is cited. Not sure if this is a necessary disclosure or not.

ref. For birds, flocks promise safety – especially if you’re faster than your neighbor – https://theconversation.com/for-birds-flocks-promise-safety-especially-if-youre-faster-than-your-neighbor-264674

4 decades after the landmark book ‘Alone in a Crowd,’ women in the trades still battle bias – a professor-turned-welder reflects

Source: The Conversation – USA (2) – By Jo Mackiewicz, Professor of Rhetoric and Professional Communication, Iowa State University

A few years ago, while working as a professor and as a welder at a small repair and fabrication shop, I went looking for books about women in the skilled trades. In the few I found, one stood out in how it made way for tradeswomen’s voices: political scientist Jean Reith Schroedel’s 1985 classic “Alone in a Crowd: Women in the Trades Tell Their Stories.”

Her first book after earning her Ph.D., “Alone in a Crowd” drew on Schroedel’s own experience working blue-collar jobs. She interviewed 25 women – machinists, truck drivers, electricians and more – whose stories revealed the exhaustion, danger, harassment and pride that shaped their working lives.

In her introduction, Schroedel noted that American women’s work opportunities have expanded and contracted in step with their rights as citizens. During World War II, for example, women entered the industrial trades in large numbers, only to be forced out when the war ended. They began to find their way back to such work after the passage of the 1964 Civil Rights Act, which barred discrimination based on sex.

The women who entered skilled trades after 1964 made up just a small share of the workforce, and they faced a wide range of challenges, including sexual harassment. Schroedel’s interviewees talked at length about being harassed and threatened by co-workers and being retaliated against for reporting sexism, racism and bullying.

So what, if anything, has changed, and what’s stayed the same?

Women hold just 5% of jobs in the trades

For one thing, it’s still rare for women to work in the skilled trades. Around 95% of the trades workforce is male, according to the U.S. Department of Commerce. Discrimination remains a barrier to entry: A 2020 research review published by sociologist Donna Bridges and her colleagues found that sexual harassment, stereotyping, ostracization and surveillance kept women from entering and staying in construction trades.

According to a 2023 analysis of 25 studies by Kimberly Riddle and Karen Heaton, sexual harassment of tradeswomen becomes more likely when male workers view women as outsiders, when women have less seniority and when jobs are physically demanding. These issues were common in 1985, and they remain so today.

Heather, a Howe’s employee, working at the lathe in the machine shop. According to the U.S. Bureau of Labor Statistics, 4.8% of U.S. machinists are women.
Jo Mackiewicz

In addition to these meta-analyses – or studies of studies – new research has revealed other similarities between 1985 and now. In a study published in 2022, sociologist Elizabeth Wulff and her colleagues interviewed 15 tradeswomen and found that types of social and cultural capital, such as growing up in a family of tradespeople and being physically strong, led them to be more successful.

Meraiah Foley, a researcher who studies workplace gender equity, and her co-researchers focused on how tradeswomen experience gender harassment – harassment not sexual in nature but focused on gender characteristics. Studying women in aviation and automotive repair in 2019, they found women experience “jokes, jibes, and belittling comments” and bosses who allow such behavior. These behaviors reinforce the view that women are outsiders, making it harder for them to succeed.

Steps forward: Respect, research and cultural shifts

So, has anything improved for women in trades since 1985? While the research clearly shows that problems such as stereotyping, disrespect, scrutiny and harassment haven’t gone away, it would be wrong to say that nothing’s changed.

In Chapter 10 of my 2025 book “Learning Skilled Trades in the Workplace,” I discuss some of the challenges that I’ve encountered as a woman in a welding shop. But I also highlight the ways that my boss and my co-workers have respected my ideas and input, have encouraged me when I’ve made mistakes, have praised my successes, and have generously shared their knowledge.

It’s possible to see change in apprenticeship programs aimed at girls and women, scholarships for women studying trades, professional organizations to support tradeswomen, and, perhaps most important, growing numbers of women in apprenticeships and skilled-trades work. While the problems that tradeswomen encounter in 2025 haven’t changed in nature since 1985, it seems these problems are more readily acknowledged and less ubiquitous.

Also, the body of research on tradeswomen is growing, which can lead to new solutions to old problems. In 2021, for example, Bridges and her co-researchers looked to scholarship on resilience to understand how male-dominated industries might better support tradeswomen. They found that mentoring, role models and networking opportunities, as well as formal health and safety rules and policies such as flexible schedules, help tradeswomen thrive.

Similarly, while most research on women in skilled trades has historically focused on tradeswomen in the U.S., Australia, New Zealand and other Western countries, new scholarship is providing insight into the experiences of tradeswomen elsewhere.

For example, education researchers Joyceline Alla-Mensah and Simon McGrath published an article in March 2025 about barriers to Ghanaian women’s participation in skilled trades. Their interviews brought to light new findings – for example, the importance of land ownership to Ghanaian tradeswomen. Researchers are just now beginning to understand the experiences of women in trades all around the world.

Back in 1985, Schroedel wrote that she had three goals for “Alone in a Crowd”: to let women doing nontraditional work know that they’re not alone, to shed light on their work situations, and to tell the largely overlooked stories of working-class women.

While the outlook for tradeswomen is brighter than it was back in 1985, it would nevertheless be possible to begin a 2025 sequel to “Alone in a Crowd” with the same three goals. And that says something about how far the U.S. has yet to go.

The Conversation

I work for Howe’s Welding and Metal Fabrication.

ref. 4 decades after the landmark book ‘Alone in a Crowd,’ women in the trades still battle bias – a professor-turned-welder reflects – https://theconversation.com/4-decades-after-the-landmark-book-alone-in-a-crowd-women-in-the-trades-still-battle-bias-a-professor-turned-welder-reflects-262307

Pneumonia vaccines for adults are now recommended starting at age 50 – a geriatrician explains the change

Source: The Conversation – USA (3) – By Laurie Archbald-Pannone, Associate Professor of Medicine and Geriatrics, University of Virginia

A new version of the pneumonia vaccine that specifically targets strains that affect adults helped spur the updated recommendations. zoranm/E+ via Getty Images

Autumn brings a chill in the air – and the start of another season of respiratory illnesses, which can be especially hard for older adults.

Although vaccine recommendations have been in flux, the Centers for Disease Control and Prevention’s recommendations on respiratory vaccines for older adults remain robust.

As a geriatrician treating primarily patients age 65 and older, I’ve found that my patients are often unsure which of the various types of pneumonia vaccines is the best option for them.

Until recently, the CDC recommended that everyone age 65 and older get a pneumonia vaccine. A year ago, in October 2024, the CDC lowered the recommended age from 65 to 50 due to a growing recognition that pneumonia can cause serious illness in people ages 50-65 – especially people who have other conditions that make them particularly vulnerable.

Pneumonia basics

Pneumonia most commonly occurs when a bacterium called Streptococcus pneumoniae infects the lungs. The infection can spur an outsize immune response and damage cells.

The first vaccine for pneumonia was developed more than 100 years ago, at the request of the South African mining industry, which was losing a startling 5% to 10% of workers to the disease each year.

For decades the most widely used pneumonia vaccine for adults was the so-called 23-valent vaccine, or PPSV23, which was approved in 1983 and protected against 23 strains of pneumococcal bacteria. In 2014, the PCV13 vaccine, which protected against 13 types of these bacteria, became the first pneumonia vaccine to be routinely recommended for adults age 65 and older. This vaccine was made using a newer technology that is thought to be more effective.

Patient gets a vaccine from a doctor.
The pneumonia vaccine has been recommended for older adults since 2014.
fstop123/E+ via Getty Images

Since then, three other pneumonia vaccines for adults, also made using the newer technology, have been licensed and added to the list of those recommended for older adults. The most recent of these is PCV21, which was approved in 2024 and specifically targets strains that usually affect adults rather than children.

Which specific pneumonia vaccine you get will depend on your medical conditions and other health factors. Your health care provider will determine the most appropriate option, but you can learn more about pneumonia vaccines on the CDC’s website and bring specific questions to your next health care visit.

Why did the guidelines change?

As the population of older adults rises, research suggests that without intervention, the number of people hospitalized with pneumococcal pneumonia could nearly double by 2040. About 150,000 Americans are hospitalized with pneumococcal pneumonia each year.

Although the Advisory Committee on Immunization Practices, the independent body that advises the CDC on vaccines, had previously considered lowering the recommended age to receive the vaccine from 65 to 50, the approval of PCV21 provided a push. Because the rate of pneumococcal pneumonia was so high in this age group, they moved to adopt the recommendation.

The pneumonia vaccine boosts the immune system’s ability to fight off this bacterium and lowers the likelihood of getting pneumonia – and of getting seriously ill, getting hospitalized, being put on a breathing machine or dying from a pneumonia infection.

According to the CDC, the old vaccine, PPSV23, is 60% to 70% effective in preventing invasive pneumonia, the more serious version of the disease in which pneumococcal bacteria infect the major organs and the blood. Althoughtis new, its mechanism and the strains it covers suggest it is even more effective, especially for people living in nursing homes or other long-term care facilities.

Who should get the vaccine?

Older age is the clearest risk factor for getting sick from pneumonia. So, if you’re like me and you are planning for an upcoming 50th birthday – and have never gotten the pneumonia vaccine before – make sure to put “get the pneumonia vaccine” on your birthday list.

If you’re an adult under 50 years old with a high risk condition, such as chronic liver disease or diabetes, the CDC also recommends you get vaccinated for pneumonia.

And make sure to talk with your health care provider to see that you’re also up to date on all recommended vaccines, which could include shingles, flu, RSV and COVID-19.

The Conversation

Laurie Archbald-Pannone receives funding from USDA and Prime, Inc

ref. Pneumonia vaccines for adults are now recommended starting at age 50 – a geriatrician explains the change – https://theconversation.com/pneumonia-vaccines-for-adults-are-now-recommended-starting-at-age-50-a-geriatrician-explains-the-change-262009

Millennial pink, gen Z yellow, brat green… Tell me your favourite colours, and I’ll guess your generation

Source: The Conversation – France – By Sabine Ruaud, Professeur de marketing, EDHEC Business School

Although each generation seems to adopt a particular palette, it would be simplistic to view this as a biological or universal phenomenon. While colour is the visual effect produced by the spectral composition of light that is emitted, transmitted or reflected by objects, how we interpret it is above all a social and cultural construct, shaped by customs, ideologies and media influences.

As French historian Michel Pastoureau, points out, colours are not created by nature – nor solely by the eye or the brain – but by society, which assigns them different meanings depending on the era. They thus become a kind of indicator of the transformations of each decade.

In the chapter section titled La Couleur, marqueur créatif générationnel? (Colour: a generational creative marker?) recently published in Les Dessous de la creativité – gagner en confiance creative et relever les défis (The Secrets of Creativity: Gaining Creative Confidence and Overcoming Challenges), we explore how successive generations are defined by sets of values, beliefs and behaviours that also manifest visually – most notably through their own distinctive colours.

Segmenting by generation – boomers, X, Y, Z, Alpha – thus allows us to observe chromatic preferences that are not merely matters of individual taste, but reflections of a collective relationship to time, aspirations and dominant aesthetics.

Each generation has its own colour code

Baby boomers (born between the end of the second world war and the mid-1960s) and generation X (1965 to 1980) gravitated toward more traditional palettes, with a dominance of neutral and pastel tones. From the 1970s onwards, these were enriched by earthy hues drawn from nature – greens, browns and rust reds.

Generation Y, or millennials (1980 to mid-1990s), saw the rise of an iconic colour: millennial pink. More than just a hue, this soft pastel became emblematic in the 2010s – symbolising lightness, optimism and, above all, a challenge to traditional gender codes.

For generation Z (1995–2010), the first standout shade was a bold yellow, quickly dubbed gen Z yellow, which emerged around 2018 in deliberate contrast to their predecessors’ pink. Soon after, purple entered the mix – long associated with power, creativity and feminist struggles, and now reinterpreted as a symbol of inclusivity and self-expression. More recently, green has gained ground. On one hand, it has become a rallying colour for ecological concerns and in political discourse; on the other, it has been reinvented as the provocative, screen-bright brat green, popularised in 2024 by British singer Charli XCX.

Generation Alpha, still in its early years, moves between two poles: a pull toward natural, comforting tones, and early immersion in the saturated, artificial colours of the digital world.

Being rooted in one’s time

While these generational markers are compelling, they should not be taken as fixed. Colours are never static: they circulate, evolve, and reinvent themselves. They return in cycles, much like fashion, and take on new meanings along the way. This fluidity is what gives colour such power in communications. It anchors a brand in its era, while also leaving space for reinterpretation.

The latest trends for 2024–2025 make this clear. Alongside the neon green tied to Charli XCX’s album “Brat”, Pantone has named Mocha Mousse, a warm, indulgent brown that speaks to a collective yearning for comfort and stability, its 2025 Colour of the Year. The contrast between these two signals – one ironic and exuberant, the other quiet and reassuring – captures the spirit of our moment, poised between excess and a quest for balance.

The power of colour naming

Research in marketing also shows that a colour’s impact lies not just in the hue itself, but in how it is named.

The name given to a colour directly shapes consumer preference and purchase intention. An evocative, poetic or playful name generates far more engagement than a generic label. This phenomenon – still underexplored – reminds brands that language can shape perception just as strongly as colour does. But humour or quirkiness must be handled with care: too much can blur brand recall, making balance essential.

For companies, the challenge is twofold. First, to understand the generational codes that shape how colours are read and received, so they can speak in an instantly recognisable visual language. Second, to build a colour system that remains coherent and sustainable over time.

Talking about generational colours is therefore a useful decoding tool – provided we recognise its flexibility. For every generation, colour is more than an aesthetic choice: it is a carrier of meaning, a witness to its time, a source of emotion, and a shared language that binds individuals to the spirit of their age.


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The Conversation

Les auteurs ne travaillent pas, ne conseillent pas, ne possèdent pas de parts, ne reçoivent pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’ont déclaré aucune autre affiliation que leur organisme de recherche.

ref. Millennial pink, gen Z yellow, brat green… Tell me your favourite colours, and I’ll guess your generation – https://theconversation.com/millennial-pink-gen-z-yellow-brat-green-tell-me-your-favourite-colours-and-ill-guess-your-generation-265326

Guinée-Bissau : une élection présidentielle sous le signe d’une instabilité chronique

Source: The Conversation – in French – By Vincent Foucher, Chargé de recherche CNRS au laboratoire Les Afriques dans le Monde (LAM), Sciences Po Bordeaux

Les tensions montent en Guinée-Bissau à l’approche de l’élection présidentielle prévue le 23 novembre 2025. L’Assemblée nationale, dominée par l’opposition, a été dissoute en 2023. Quant àu président Umaru Sissoco Embaló, son mandat a pris fin en septembre. La justice bissau-guinéenne menace le principal opposant, Domingos Simões Pereira, qui vient d’annoncer son retour d’exil. Dans ce contexte tendu, l’armée mais aussi le trafic de cocaïne, qui implique une partie des élites politiques et militaires, restent déterminants. Le politologue et spécialiste de la région, Vincent Foucher, analyse pour The Conversation Africa les causes de cette instabilité récurrente.


Pourquoi le pays replonge-t-il si souvent dans des crises institutionnelles ?

La crise actuelle s’inscrit dans l’histoire et les structures économiques du pays. D’abord, la Guinée-Bissau est le seul pays d’Afrique de l’Ouest qui ait pris son indépendance, en 1973, au terme d’une lutte de libération (contre les colonisateurs portugais en l’occurrence). Ceci a donné un poids numérique (et budgétaire) et une légitimité à une armée qui se croit autorisée à intervenir dans le champ politique.

Ensuite, il s’agit d’un petit pays enclavé, encore très rural, qui avait été peu « mis en valeur » par le pouvoir colonial portugais. Aujourd’hui encore, la base économique du pays reste très faible. C’est une noix apéritive, la noix de cajou, qui fait l’essentiel des exportations.

Le gros de la population se débrouille pour subsister dans les campagnes. Mais pour la petite élite urbaine, l’accès à l’État est absolument essentiel : être au pouvoir permet d’avoir les quelques contrats publics disponibles (beaucoup d’hommes politiques sont en même temps commerçants et entrepreneurs), mais aussi des avantages proprement vitaux, comme la possibilité de faire financer au compte de l’État des soins médicaux à l’étranger – le système de santé local est en très mauvais état.

Pour vivre, il faut donc être au pouvoir. Ceci détermine une sorte de cycle : une coalition de mécontents et d’opposants se forme ; elle parvient à prendre le pouvoir par des moyens légaux (élections ou formation d’une nouvelle coalition majoritaire à l’Assemblée) ou bien par des moyens illégaux ; la répartition des avantages suscite des mécontentements dans la coalition, qui se fissure progressivement ; une nouvelle coalition se forme qui va tenter de prendre le pouvoir…

Cette tendance à l’instabilité factionnelle est encore aggravée par des dimensions institutionnelles. En effet, la Constitution actuelle est une sorte de compromis, résultat de crises précédentes. Elle est de type mixte, bicéphale, semi-présidentielle, avec un président puissant et un Premier ministre autonome, normalement issu de la majorité parlementaire. La constitution bissau-guinéenne diffère ainsi des régimes présidentiels plus stables des pays voisins. Ses flous permettent des interprétations et des manœuvres, rendant rares les résolutions institutionnelles crédibles.

C’est cet ensemble de facteurs qui explique la récurrence des crises politiques, et l’on a bien du mal à voir le chemin de sortie.

Quels sont les facteurs qui vont influencer le résultat de la prochaine élection présidentielle ?

Assez bizarrement, depuis le passage du pays à des élections pluralistes en 1994, même si le jeu politique est très tendu, les scrutins se passent plutôt bien et ont été plutôt crédibles. Est-ce que, cette fois-ci, les choses seront différentes ? Le président sortant, Umaro Sissoco Embaló, semble plutôt nerveux et il défend assez « haut ».

Dès 2023, Embaló a paralysé l’Assemblée nationale – contrôlée par le principal parti d’opposition, le Parti africain pour l’indépendance de la Guinée-Bissau et du Cap-Vert (PAIGC). Récemment, il vient de placer des alliés à des postes clés, notamment à la cour suprême et à la commission électorale. Il utilise la justice pour neutraliser ses opposants, et beaucoup d’observateurs estiment qu’il est derrière une série d’agressions mystérieuses dont certains de ses critiques ont été victimes.

Par ailleurs, Embaló s’emploie à recréer une coalition. Après avoir rompu avec le parti sous le drapeau duquel il s’était fait élire, le Mouvement pour l’alternance démocratique (Madem), il s’est récemment réconcilié avec le chef de ce mouvement, l’homme d’affaires Braima Camará, qu’il a nommé Premier ministre.

Le principal adversaire d’Embaló, Domingos Simões Pereira, président du PAIGC, avait dû se résigner à l’exil pour échapper à des poursuites qui semblent, en partie au moins, politiques, mais il vient d’annoncer son retour. Prendra-t-il vraiment le risque d’une arrestation ? Et s’il n’est pas candidat, qui pourra faire campagne et avec quelles ressources ? Quel est l’état réel d’un électorat bissau-guinéen très composite et qui évolue sur le plan démographique ? Si Embaló suscite beaucoup de réserves parmi les élites urbaines, a-t-il su consolider son influence dans d’autres réserves de voix ? Ses alliés supposés, et notamment Braima Camará, vont-ils effectivement mobiliser pour lui ?




Read more:
Crise politique en Guinée-Bissau : la démocratie ou l’autoritarisme ?


Quel est le rôle de l’armée dans cette lutte pour le pouvoir ?

Comme je l’ai mentionné, l’armée joue un rôle historique lié à la lutte de libération du pays. Depuis la libéralisation politique des années 1990, elle surveille de près la vie politique, car elle craint d’être réformée, de voir son poids et ses budgets réduits. Or l’armée est un point d’accès essentiel à l’État pour un certain nombre de gens, notamment parmi la communauté balante.

Lors de la guerre civile de 1998-1999, l’armée s’était donc rangée massivement contre le président Nino Vieira, qui tentait de réduire son poids, son coût et son influence.

Depuis, beaucoup d’acteurs politiques cultivent leurs relations avec certains chefs militaires pour tenter de s’imposer. Cela a abouti parfois à des épisodes très violents, comme en 2009, quand le chef d’état-major d’alors a été tué dans un attentat et que des militaires sont allés ensuite assassiner le président Vieira.

En 2012, l’armée avait finalement pris le pouvoir directement, obtenant le départ d’une force angolaise que le Premier ministre PAIGC d’alors, Carlos Domingos Gomes Jr, avait amenée, sans doute dans l’espoir de réformer l’armée à sa façon. Mais ce coup d’État avait suscité une réprobation internationale et un isolement douloureux pour le pays, et l’armée avait rendu le pouvoir aux civils en 2014, tout en prenant soin de maintenir le PAIGC à distance du pouvoir.

Embaló a remporté son premier mandat grâce au soutien de l’armée, qui a consolidé son élection en 2020 en prenant le contrôle du Parlement. Depuis, il entretient de bonnes relations avec l’armée tout en restant méfiant, n’étant pas issu de la communauté balante dominante dans les hauts rangs militaires, à commencer par le chef d’état-major général, Biague na Ntan.

De façon symptomatique, Embaló a fait revenir à Bissau la petite mission militaire de la Communauté économique des États de l’Afrique de l’Ouest (Cedeao) qu’il avait d’abord fait partir après sa prise de fonction et qui a pour mission de « protéger les institutions ». Surtout, il a formé une garde présidentielle importante et à sa main.

Quelques signes récents suscitent l’inquiétude. D’abord, Rui Duarte Barros, le Premier ministre qu’il a évincé pour renouer avec Braima Camará, est un proche parent du chef d’état-major général.

Ensuite, depuis que Embaló a rompu avec le chef de sa garde (pour des raisons jamais éclaircies mais qui suscitent beaucoup de rumeurs), ce dernier est à l’état-major, dans une forme de détention qui pourrait aussi bien être une manière de le protéger contre le président.

L’armée bissau-guinéenne pourrait bien se sentir à nouveau légitime pour intervenir en cas de crise politique. L’exemple des juntes voisines pourrait bien renforcer cette tentation.

La Guinée-Bissau est souvent décrite comme un narco-État. Est-ce un facteur politique ?

La Guinée-Bissau s’est en effet fait remarquer comme hub lors d’une première poussée du trafic de cocaïne d’Amérique latine vers l’Europe par l’Afrique, à partir du milieu des années 2000. Les trafiquants internationaux ont cultivé des connexions au sein des élites politiques et sécuritaires à Bissau. Dans un épisode célèbre, la police sénégalaise avait trouvé en 2007 dans une ferme occupée par des trafiquants colombiens un tableau blanc avec un organigramme de l’État bissau-guinéen…

Les trafiquants en Afrique de l’Ouest ont collaboré avec des segments des élites locales. Mais le trafic est compétitif, chaotique et très visible, contrairement aux pays voisins où il est mieux tenu et plus discret. En Guinée-Bissau, les conflits internes ont même parfois permis à la police judiciaire d’agir, même si la justice a au final souvent laissé s’échapper les principaux responsables. Cette instabilité a même pu détourner les gros trafiquants latino-américains vers des pays plus stables.

L’argent de la drogue s’est donc ajouté aux autres ressources et enjeux qui alimentent les luttes politico-militaires, comme les contrats publics, le bois et les licences de pêche. Ainsi, selon un proche, le chef d’état-major Tagme na Wai, assassiné en 2009, lui aurait confié qu’il n’avait d’autre choix que de s’impliquer dans le trafic s’il voulait garder le contrôle de l’armée, car des chefs militaires concurrents utilisaient l’argent de la drogue pour renforcer leur influence sur la troupe.

Des soupçons pèsent en tout cas sur Embaló et sur sa volonté de lutter contre le trafic, en particulier avec le besoin d’argent que suscitent les élections à venir. Depuis qu’il est au pouvoir, des trafiquants notoires sont de retour à Bissau, et des affaires judiciaires ont tourné court – ainsi, en 2022, la justice bissau-guinéenne a acquitté deux trafiquants connus, poursuivis après une saisie de 1,8 tonne de cocaïne.

The Conversation

Vincent Foucher does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.

ref. Guinée-Bissau : une élection présidentielle sous le signe d’une instabilité chronique – https://theconversation.com/guinee-bissau-une-election-presidentielle-sous-le-signe-dune-instabilite-chronique-265112

Pendant des siècles, les plantes n’ont cessé de changer de nom, voici pourquoi cela est en train de s’arrêter

Source: The Conversation – France (in French) – By Yohan Pillon, Chercheur en botanique, Institut de recherche pour le développement (IRD)

Page consacrée aux palmiers du _Meyers Konversations-Lexikon_, datant de la fin du XIX<sup>e</sup>&nbsp;siècle, l’ouvrage encyclopédique de référence, en langue allemande. Bibliographisches Institut

Selon les époques et les naturalistes, de nombreuses plantes ont pu changer de nom et de famille. La collaboration internationale des scientifiques et les progrès réalisés par le séquençage de l’ADN permettent aujourd’hui de s’accorder sur la classification.


Un botaniste entend souvent dire qu’il est une personne qui passe son temps à changer le nom des plantes. C’est de moins en moins vrai. Car l’utilisation du séquençage ADN permet de reconstruire les liens de parenté entre les espèces, et car les chercheurs de différents pays coopèrent bien plus qu’avant.

Retour sur un travail collectif qui dure depuis des siècles : celui de la classification des plantes.

La classification botanique, une quête individuelle

Portrait de Carl von Linné.
National museum, CC BY

Le naturaliste suédois Carl von Linné est généralement considéré comme le père de la taxonomie moderne, c’est-à-dire la branche de la biologie qui tâche de nommer et de classifier les espèces animales et végétales. Au XVIIIe siècle, ce naturaliste va populariser ce que l’on appelle la nomenclature binomale qu’on utilise encore aujourd’hui. Il s’agit du nom scientifique ou « latin » que porte chaque espèce identifiée.

Il est composé de deux mots, pour la pomme de terre, par exemple, ce sera Solanum tuberosum. Le premier mot représente le nom de genre auquel appartient l’espèce que l’on décrit, le deuxième est l’épithète spécifique. Il donne souvent une caractéristique supplémentaire. Ici il est indiqué que cette plante du genre Solanum forme des tubercules.

La classification des organismes est depuis en constante évolution au fur et à mesure de l’avancée des connaissances. Ainsi Linné avait d’abord classé les baleines parmi les poissons avant de les ranger dans les mammifères dans la dixième édition de son ouvrage Systemae Naturae (1758), où elles sont restées depuis.

La classification des organismes s’organise selon plusieurs niveaux hiérarchiques : espèces, genre, famille, ordre, etc. avec des niveaux intermédiaires.

Le rang de familles occupe un rôle important car pour le botaniste amateur ou professionnel c’est généralement la première étape à franchir, reconnaître à quelle famille appartient une plante pour savoir à quelle page ouvrir sa flore ou ouvrage d’identification. La notion de famille est ancienne, puisqu’introduite en 1689 par le directeur du jardin botanique de Montpellier, Pierre Magnol.

Aujourd’hui, les quelques 300 000 espèces de plantes à fleurs sont rangées dans 416 familles comme les Graminées (ou Poacées), les Orchidées, les Cucurbitacées ou les Rosacées. Ces familles sont des ensembles plus ou moins naturels qui peuvent souvent être définis par plusieurs traits morphologiques. Les plantes de la famille des Orchidées sont par exemple généralement des plantes herbacées avec un pétale très différent des autres (le labelle) conférant à la fleur une symétrie bilatérale, des organes mâles et femelles soudés (la colonne) et de très petites graines.

La classification des plantes a longtemps été une affaire d’experts, solitaires, qui regroupaient entre elles les plantes qui se ressemblaient. On comptait ainsi autant de classifications que d’éminents botanistes : Engler, Cronquist, Dahlgren, Thorne, Takhtajan, etc. Certaines plantes pourtant communes comme le muguet, la jacinthe ou le micocoulier, ont ainsi été placées dans différentes familles selon les auteurs.

Le séquençage ADN au service d’une nouvelle classification collégiale

Mais à la mi-temps du XXe siècle, une découverte va tout changer : celle de la double hélice ADN en 1953, puis du séquençage de cet ADN. En déterminant la succession des lettres A, T, G et C dans des gènes communs à toutes les plantes, il a été possible d’accumuler un grand nombre de caractères pour comparer de façon objective les espèces. Des analyses dites cladistiques permettent ainsi de transformer les alignements de séquences ADN d’espèces différentes en arbres généalogiques représentant les liens de parentés entre ces espèces. Ce sont sur ces arbres que s’appuient les nouvelles classifications. Cette méthode nouvelle permet désormais de déterminer plus précisément les liens de parentés entre les espèces, c’est-à-dire la phylogénie et ainsi de mieux comprendre leur évolution.

En 1993, un collectif international de chercheurs met en commun leurs données de séquences d’ADN d’un gène clé de la photosynthèse (le gène rbcL) et reconstruisent la première phylogénie moléculaire à large échelle des plantes à fleurs.

D’autres études succédèrent et en 1998, un collectif, l’Angiosperm Phylogeny Group, décida d’utiliser ces arbres phylogénétiques pour établir une nouvelle classification des plantes à fleurs. Dans un article publié dans le quotidien britannique The Independent, il sera même écrit « Une rose est toujours une rose, mais tout le reste de la botanique est chamboulé ».

Plusieurs mises à jour de cette classification APG ont été publiées depuis, avec APG II (2003), APG III (2009), et APG IV (2016). Une cinquième version en cours de rédaction a été annoncée au dernier congrès international de botanique qui s’est tenu en juillet 2024 à Madrid.

Une classification partiellement chamboulée

Mais alors, la phylogénie moléculaire a-t-elle vraiment bouleversé la classification des plantes ? Pour mesurer cette disruption plus objectivement, nous avons utilisé la Nouvelle-Calédonie comme modèle. Ce territoire est particulièrement bien adapté pour les études de botanique historique car il est connu pour sa flore extrêmement riche et originale : 75 % des espèces de plantes vasculaires ne poussent nulle part ailleurs dans le monde, on dit ainsi qu’elles sont endémiques.

De plus, bien que l’archipel ne représente qu’un pourcent des espèces de plantes à fleurs du globe, on y retrouve malgré tout 42 % des familles de plantes à fleurs actuellement reconnues. Des listes complètes des espèces de plantes natives de Nouvelle-Calédonie ont ainsi été publiées en 1911, 1948, 2001, 2012, puis suivies de mises à jour plus régulières. Nous avons donc utilisé ces listes couvrant plus d’un siècle pour retracer la classification de chaque espèce à travers le temps.

Notre étude montre que les transferts d’espèce d’une famille vers une autre ont toujours été communs avant la découverte de l’ADN, y compris entre les deux listes publiées par le même auteur, le botaniste André Guillaumin, en 1911 et 1948 (10 % des espèces). On compte le plus grand nombre de mouvement d’espèces entre famille (16 %) entre 2001 et 2012, au moment où la classification APG a été appliquée pour la première fois à la flore de la Nouvelle-Calédonie. Depuis, le rythme s’est largement ralenti avec seulement 15 espèces (0,5 %) qui ont changé de famille entre 2012 et 2024. Il ne reste presque plus aucun changement de famille à prévoir dans cette flore dont la classification familiale semble aujourd’hui stable.

Mouvement d’espèces de monocotylédones pétaloïdes natives de Nouvelle-Calédonie entre différentes familles à travers les classifications, de 1911 à 2024
Mouvement d’espèces de monocotylédones pétaloïdes natives de Nouvelle-Calédonie entre différentes familles à travers les classifications, de 1911 à 2024.
Fourni par l’auteur

Pour une classification moderne et consensuelle

Mais s’il est devenu relativement aisé de changer les noms d’espèces et de mettre à jour la classification des plantes dans les bases de données en ligne aux actualisations presque quotidienne, cela n’est pas vrai dans d’autres domaines. C’est un tout autre travail (et un autre budget) de réorganiser les herbiers, les jardins botaniques, mettre à jour les étiquettes dans les jardineries, etc. Si les changements constants avaient pu décourager certains de mettre à jour leur collection, cette nouvelle stabilité pourrait motiver certains à franchir le pas et embrasser cette classification moderne.

Une classification qui reflète les relations de parenté des espèces a de nombreux avantages. Elle est plus stable car lorsque la phylogénie est établie avec un degré de certitude, la classification ne changera plus. De plus, des espèces proches ont plus de chance de partager des caractères communs et donc ce genre de classification est plus précis pour prévoir les propriétés des plantes : comestibles, médicinales, toxiques, allergènes. Une telle classification est donc plus désirable pour valoriser, et préserver, la biodiversité en péril.

The Conversation

Yohan Pillon ne travaille pas, ne conseille pas, ne possède pas de parts, ne reçoit pas de fonds d’une organisation qui pourrait tirer profit de cet article, et n’a déclaré aucune autre affiliation que son organisme de recherche.

ref. Pendant des siècles, les plantes n’ont cessé de changer de nom, voici pourquoi cela est en train de s’arrêter – https://theconversation.com/pendant-des-siecles-les-plantes-nont-cesse-de-changer-de-nom-voici-pourquoi-cela-est-en-train-de-sarreter-263558