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Chimp Culture

Many animals know everything they need to know by instinct. They don’t need to learn from those around them to grow up, feed themselves, or even communicate with other members of their species. Humans are unique in how many varied and distinct cultures we have. Cultures teach us everything from how to talk, to how we should eat, to what we believe about families, social rules, and what it means to be an adult. The rules of human culture are vast. But we aren’t unique in having cultures. A few other species are also known to transmit knowledge and rules from generation to generation.

Chimpanzees are another species with cultural differences. Researchers have studied chimpanzee behaviors, for example in how they use tools to “fish” for termites, in depth in a few specific locations where chimpanzees live in the wild. But researchers at the Max Planck Institute for Evolutionary Anthropology in Germany set out to study chimpanzee behavior in many different locations.

The researchers set up consistent methods to record chimpanzee behavior so they could reliably compare similarities and differences across locations.

Chimpanzee “fishing” involves fashioning a tool from a stick that the chimps poke into termite nests to draw out the bugs, which the chimps eat. After carefully observing the techniques chimps used to fish for termites in ten different places, the researchers were surprised to discover that each community has a unique and specific way of fishing.

For example, some chimpanzees lie down on their sides to termite fish, while others lean on their elbow, and those in a third location sit while fishing. In one place, chimpanzees unravel the fibers at one end of their fishing stick to create a brush, and then rest the termite-covered stick on their wrist while they eat. In another location, the chimps don’t make a brush end with their stick but use their mouth to shake the stick when it’s in a termite nest.

The researchers pointed out that the chimpanzee communities live in similar habitats, so ecological differences don’t explain the different fishing styles.

Videos tracking chimps in the wild collected during this project are available to view online. Researchers encourage citizen scientists to contribute to analyzing the collected data to make more discoveries: Chimp and See project

The photo shows a bonobo at the San Diego Zoo fishing for termites. Credit: Mike Richey.


Listening to Animals

Have you ever wished you could understand what animals are saying? How would you figure out animal language? In a new study, biologists from South Korea and Poland explained the steps they took to try to interpret exactly what birds called the oriental tit (species name Parus minor) are saying when they call out in alarm.

Oriental tits raise their babies in hollows in trees or in nest boxes. They do not have to worry about predators who cannot squeeze through their small nest entrances. But snakes can squeeze into a nest, and oriental tits have a specific alarm call when a snake comes near. When little nestlings hear this call, they jump out of their nest.

The alarm call for when tits see snakes is different from the call when they see a large bird, like a crow or jay. Large birds can also be a menace because they will attack young birds when they are out of their nests but are too big to get into nests.

The biologists wondered if the tit parents would use the same kind of call they use for snakes for when they see chipmunks, which are also common where the birds live and can get into nests. The researchers found that the bird calls for chipmunks are different than for snakes. The biologists concluded that the bird has a very specific call that means “beware of snake!” The call does not translate to “beware of predators that can get into our nest!” The young birds only jump out of their nests when they hear the snake call, maybe because snakes are more likely to eat the birds in their nests than chipmunks are.

Photograph shows Parus minor. Credit: Alpsdake

What Will Schools Be Like When They Reopen?

The US Centers for Disease Control and Prevention (CDC) have put out recommendations for how to protect students and school staff from COVID-19 and slow its spread. Even though school is canceled for many students through the rest of the school year, it’s important for school officials to plan for how schools will be different when they reopen.

The CDC guidelines note that the more people interact, and the longer the interactions, the higher the risk of COVID-19 spread. To reduce the risk of COVID-19 exposure and spread, they recommend:

  • As much as possible, students should be in small groups that stay together, along with the same teacher if possible.
  • Students should stay at least 6 feet apart and not share materials.
  • Students should sit facing in the same direction instead of turned toward each other.
  • Anyone who has symptoms like a cough, sore throat, or fever, or has recently been close to someone with COVID-19 should stay home.
  • Everyone should be required to wash their hands regularly with soap and water for at least 20 seconds, or at least use hand sanitizer.
  • Everyone should cover coughs and sneezes with a tissue, which is thrown out, with hands washed or sanitized immediately afterward.
  • Except for younger students, everyone should use cloth face masks, especially when it’s hard to stay physically apart.
  • Schools should have enough supplies like soap, hand sanitizer, paper towels, tissues, cleansers, cloth masks, and touch-free trash cans.
  • Schools should remind everyone of proper procedures in signs, announcements, and videos.
  • Anything that is touched often should be cleaned often, in schools and on school buses.
  • Children should keep their belongings and supplies separate and not share devices and other learning tools.
  • School spaces should have good air ventilation.
  • Shared spaces like lunch rooms and playgrounds should be closed, or else have only a few people using them at any given time, with the spaces cleaned between uses.
  • Food shouldn’t be served in a way that allows germs to be shared.
  • People who are at greater risk of becoming very sick if they catch COVID-19, for example because of a medical condition like diabetes, should be allowed to study or work from home.
  • Schools should avoid gathering people in big groups or having outside visitors.
  • Technology should continue to be used to gather virtually.
  • School systems should consider having staggered schedules, with classes beginning and ending at different times for different groups, to limit the number of people who are together.
  • Schools should consider doing daily health checks, for example scanning everyone’s temperature as they arrive.

Source: CDC Considerations for Schools

Pampered Pets and Well-Fed Pests

Animals that are adapted to life with humans thrive. Many dogs and cats who live with well-off owners get more attention and medical care than poor people. Even animals that humans consider pests prosper. The house mouse, whose species name is Mus musculus, is more widespread around the world than any other type of rodent.

Archeologists and biologists from eight countries on four continents recently published a study tracking the history of the house mouse. They followed how human activities have helped the animal spread over the last 20,000 years, from the Middle East to Europe 4,000 years ago. They note that the spread of mice to Europe coincided with the introduction of widespread pet cats, with cats suddenly becoming useful.

Image of Mus musculus by George Shulkin.

How Exactly Do We Stop Climate Change? Plus a Summer Forecast for COVID-19

Some people on social media obsessively replace all their plastic belongings with stuff made from stainless steel, ceramic, or glass. Other environmentalists rail against fossil fuel companies and say regular people don’t need to change their behavior to stop climate change; we just need to put rich oil company heads in prison. But what do 400 scientists say when they get together to hash out what actually causes climate change and how we humans can stop it?

Here is what actually needs to be done:

  • Transform the energy system so that instead of using fossil fuels we use renewable sources of energy.
  • Accept lifestyles where we travel much less far, both for trips and in our everyday lives.
  • Change our diets, mainly to eat less meat and waste less food.
  • Live in smaller homes, which take a lot of energy and material to heat and cool and build and fill.

And these efforts need to be made by large numbers of people, not just a few people who are trying to be perfect.

People may be more motivated to make these changes if they realize that they lead to healthier ways of life—not only because they and other people won’t have to endure as much climate havoc but because changes like driving less and eating less meat make us individually more physically fit.

Summer Forecast for COVID-19

Many people have hoped that warm weather will wipe out the COVID-19 epidemic in their area. But people eager for summer camp and pool season need to think twice. For now, local weather conditions aren’t likely to stop infections. A paper in the journal Science points out that because the virus is new and so much of the population has no immunity to it, the virus will spread quickly no matter what the local climate.

Painting above by Nairi Rivers.

Tantalizing Steps Toward a COVID-19 Vaccine. And How Does an mRNA Vaccine Work?

On Monday a company reported promising first signs for a vaccine against COVID-19. What made this news exciting was that, so far, the candidate vaccine looks safe, and taking two shots of it seems to give people as strong an immune response as found in people who have recovered from COVID-19. While this is encouraging news, the vaccine was tested on a very small number of people—only eight volunteers. There is still a long way to go before the vaccine could be ready for a large number of people to use.

Normally, developing a vaccine takes many years. Vaccines need to be tested in large numbers of volunteers, usually in three phases of experiments where each phase includes more and more people who take the proposed vaccine, to prove that it is safe and that it actually works to protect people against disease.

With COVID-19 disrupting lives in a way that hasn’t been seen for more than a century, researchers have plenty of motivation to develop a vaccine as quickly as possible, and experts like Anthony Fauci, the doctor who leads the National Institute of Allergy and Infectious Diseases, have estimated that a vaccine for COVID-19 could be ready in as little as one year.

Scientists have proposed dozens of candidate vaccines for COVID-19 in just the few months the virus has been around, and a small number of vaccine candidates are already being tested in people.

So how do vaccines work?

Normally, when someone becomes sick with a germ such as a virus, the body’s immune system recognizes the intruder and in a few days develops an army of tools to fight the invader. White blood cells fight infections by swallowing up and digesting germs, killing infected cells, and by making antibodies. Antibodies are large, Y-shaped proteins that can use their tips to recognize foreign agents very specifically. Once they recognize a particular invader, antibodies that match the invader replicate in vast numbers and then stay in the blood, ready to pounce if they ever come across the specific shape again.

Sometimes, as with a particularly dangerous germ like COVID-19, the fight between the immune system and the invading germ can get perilous, with no guarantee that the immune system will win before a person gets very sick.

Vaccines take advantage of our body’s immune system by imitating an infection without actually making people sick. Vaccines can be made from dead or weakened versions of germs or from portions of germs, such as a bit of the protein capsule that makes up the outside of a virus. If the real germ comes along later, a large number of antibodies will be ready to surround and kill the germ before the germ can get very far.

Sometimes people need to take more than one dose of a vaccine so the immune system reaction becomes strong enough to protect against an infection.

Why do vaccines sometimes make my arm sore?*

Soreness a day or two after you get a shot of vaccine is a sign that your immune system is hard at work, making antibodies. All the white blood cells milling around the vaccine can cause inflammation. Making sure to move your arm around soon after you get a dose of vaccine can help spread it around and make your arm less sore later.

How do mRNA vaccines work?

The candidate vaccine that made the news this week is made out of mRNA. No vaccine has been made from mRNA before. mRNA is a molecule normally found in almost all cells and carries code for making protein. A vaccine made of mRNA would use the body’s own protein-making machinery to make some viral proteins, which the immune system would then recognize as foreign and mount an immune response against.

An advantage of mRNA vaccines is that they are relatively fast and easy to make, so it should be possible to make large amounts of the vaccine quickly if it is proven to work well.


The image above shows a human white blood cell surrounding bacteria to fight an infection. Bacteria are colored green in this picture from an electron microscope. Source: National Institute of Allergy and Infectious Diseases

* My 9-year-old daughter—and editor—asked me this question. Do you have other questions about vaccines? Leave them for me in the comments, and I will try to answer them in a future post.

Researchers Discover How to Preserve The Scream

Some misguided souls like to think of art and science as opposites, but the two impulses are intertwined. Scientists need deep creativity to stand at the frontier of knowledge and pull something solid out of the void. And artists creating things out of the material world are just as subject to the laws of science as anyone else.

Between 1893 and 1917, the Norwegian artist Edvard Munch painted and drew several versions of The Scream, the famous image in which a man puts his hands against the sides of his head and opens his mouth to scream while his whole body seems to waver and melt in horror. Meanwhile, the skies behind him blaze with the colors of a brilliant sunset.

Munch painted two versions of The Scream, one in 1893 and another around 1910. He experimented with different types of paints and pigments to make his colors as bright as he could, including new oil paints that contained the element cadmium. The 1910 version of the painting now shows signs of damage, including paint that is flaking and whitened. The Munch Museum where the painting is kept has not displayed the painting in many years and instead has kept it stored away to try to preserve it better.

Last Friday, researchers published a study that concludes that moisture in the environment is the main cause of damage to the painting. Exposure to light is not what caused the damage seen in the painting.

The researchers knew that paints made from the chemical cadmium-sulfide, as found in the 1910 painting, have whitened, flaked, and shown other signs of damage in other works of art from the same period of time. The researchers used high-tech methods to analyze the molecules of the painting without damaging the painting. The researchers used beams of x-rays and other forms of light generated in a giant donut-shaped particle accelerator in France to study how the chemicals in the paint had changed over time. The researchers were able to find out that exposure to water in the air was the main reason the paint had degraded.

Studying the details of the painting’s chemistry provides practical knowledge that will now help guide how the museum stores the artwork. The museum can reduce humidity around the painting and since light does not seem to damage the painting, perhaps return it to public display after many years of hiding it away from view.


A Strong Immune Reaction Gives Hope for a Future COVID-19 Vaccine

Scientists around the world are racing to make a vaccine to protect against COVID-19. Scientists are also trying to figure out if people who get COVID-19 are safe from getting it again. Both of these things depend on how our immune systems respond to the new virus.

Studying 20 people who had recovered from COVID-19, scientists in California were pleased to see a strong immune response against the virus. The scientists found that people’s immune systems can recognize the virus in many different ways. This came as a big relief because seeing a strong immune response like this means it is more likely that a future vaccine will work. Also, some people have been worried that people might be able to get sick more than once from the virus, but now that looks less likely.

The scientists in California found something else interesting. Using blood samples collected before the new coronavirus existed, they found that many of the old blood samples had an immune reaction to the new coronavirus. The new coronavirus is related to other coronaviruses that cause colds, so the scientists think that people who’d had colds caused by related germs were able to recognize the new coronavirus, at least a little. That kind of response could help protect some people from getting very sick with COVID-19. If that’s true, it may explain why some people and places are less affected by COVID-19.


The image above shows an electron microscope picture of a human T cell, an important type of cell in our immune system. Source: National Institute of Allergies and Infectious Diseases

Cats Can Get COVID-19 and Pass it to Other Cats

In April, zoo keepers at the Bronx Zoo noticed that some of their lions and tigers were coughing. They tested the animals for COVID-19 and found that eight had caught the virus that was causing the coronavirus outbreak in New York City. It seems that the lions and tigers caught the virus from a zoo employee who was caring for them but didn’t yet have symptoms. Around the same time, the Centers for Disease Control and Prevention, better known as the CDC, announced that two pet cats living in different parts of New York had also tested positive for the virus after showing “respiratory symptoms.” All of the animals were said to have mild cases and recovered.

Now, a new study proves that cats can become infected with the virus and pass it on to other cats. Researchers infected three cats with virus taken from a human patient. Each of the cats caught the virus. Each was then placed in a cage with an uninfected cat, and all the companion cats also caught the virus. The researchers found virus growing in the cats’ noses. Interestingly, none of the cats had symptoms—no cough, no fever, no weight loss—and all fought off the virus eventually.

So what should cat owners do? Veterinarians recommend being careful to avoid passing COVID-19 to their pets as well as their other family members if they become sick. Also, cats should stay indoors so they can’t catch the virus or spread it to others (animals or people) in the neighborhood.


How Food Labeling Leads to Food Waste

For the first time in their lives, many people in well-off countries are being careful not to waste food. The COVID-19 pandemic has made it harder to find and buy all the food many of us normally take for granted. But food waste is a problem even when food seems plentiful, partly because not everyone in the world has as much food available to them and partly because wasting food is a huge cause of environmental damage. The United Nations has pointed out that if food waste were a country, it would be behind only the United States and China as the biggest producer of the greenhouse gas emissions that cause climate change.

In well-off countries like the United States and Australia, most food waste—61 percent—happens after people buy food. In contrast, in Sub-Saharan Africa, people end up throwing out only 5 percent of the food they buy.

One of the reasons people in well-off countries waste so much food is because of the “best by” or “use by” labels on food packages. Many people don’t realize that almost all such labels are not based on any particular scientific evidence. But people throw out large amounts of perfectly good food because date labels make them worry that the food is spoiled and unsafe to use.

To prevent food waste, a new paper argues that different types of researchers need to come together to make food labeling less confusing and arbitrary. The paper argues that food safety research is needed, along with better regulation and education.


T. rex’s Long Legs Were for Marathon Walking

With its massive, chomping jaw and fierce expression, Tyrannosaurus rex may be the most fearsome dinosaur of all. Scientists generally assumed that with their long legs, T. rexes could run at top speed to catch prey. But some researchers now think that the dinosaur’s long legs were more for endurance and efficiency than for running.

The researchers calculated how much energy dinosaurs of different weights and leg length would need to move around, and they argue that for heavy dinosaurs like T. rex, long legs saved energy while they searched for prey but didn’t necessarily help them sprint.

Hunters like T. rex spend much of their time roaming in search of food, and the researchers believe that efficiency was more important than speed for the biggest theropods like T. rex. But theropods include a wide range of meat-eating dinosaurs who generally walked on two legs. Some were as small as half a pound, as light as a rat, while others weighed nine tons, heavier than the biggest elephant. Fortunately for the lighter theropods, who were hunted as well as hunters, their long limbs did let them run at top speeds.


Coronavirus Symptoms in Children May Not Start With a Cough

In about 4 months, the coronavirus that causes COVID-19 has killed more than 285,000 people around the world. But, to everyone’s relief, extremely few of those people have been children. When COVID-19 first struck in China, it wasn’t even clear that children could catch the virus. By March, researchers figured out that children were just as likely to become infected, but they just weren’t getting as sick.

Still, it’s important to know who has the virus. Now, a study by researchers in Wuhan, China, finds that children with COVID-19 often do not have a cough, which is one of the most common symptoms that COVID-19 causes in adults. Instead, the first symptom many children have of COVID-19 is an upset stomach or diarrhea.


The image above shows an electron microscope picture of the coronavirus that causes COVID-19. Source: National Institute of Allergies and Infectious Diseases

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