【推荐2】In Shark Bay, Australia, bottlenose dolphins that aren’t related have been observed teaching each other a new way to use a tool, a behavior that until now scientists have found only in humans and other great apes. It’s also the first known example of dolphins passing on such knowledge within the same generation, rather than between generations. That’s significant, the authors say, because such social learning between peers is rare in nature.

In a practice called shelling, dolphins will chase fish into abandoned giant snail shells on the seafloor, then bring the shells to the surface and shake them with their noses, draining the water and catching the fish that fall out. In 2007, Krutzen launched a study of Shark Bay’s dolphins, identifying more than a thousand individual dolphins over 11 years. During this time, scientists observed shelling 42 times among 19 dolphins. Half of these events occurred after a marine heatwave in 2011, which may have caused a die-off among giant sea snails, leading to more abandoned shells on the seafloor.

Because of the length of their study, scientists had thorough knowledge of the individual dolphins, family histories, ages sexes, and behavior, making it easier for them to study the 19 dolphins that practiced shelling. For instance, they observed that the dolphins that practice shelling hang out with other shelling hunters, so it’s likely that they copy the action from those they spend time with, says study lead author Sonja Wild, a postdoctoral researcher at the University of Konstanz in Germany. Although 42 observations are a small data set, the scientists add it’s likely the behavior is actually common; it only lasts a few seconds, making it harder for people to spot it from a boat.

The team had assumed that environmental factors — specifically, whether shelling dolphins did so simply because they lived in a shell-rich area — could explain this peer-to-peer transmission (传递). A genetic trait (遗传特性) among a family group was another possible reason.

So the researchers combined their data on the dolphin sightings, as well as genetic and environmental data, into a computer model that proposed various ways shelling could be passed on between dolphins. The model that supported this kind of transmission was the strongest outcome, according to the study.

【推荐2】Scientists are excited by the rediscovery of the giant lacewing. It is an insect which looks like a cross between a fly and a moth. It has spotted wings with a span of roughly 50 millimeters, holding the wings over its body like a tent.

Giant lacewings have been around since the Jurassic era, a period of time about 150 to 200 million years ago. In the 1950s, scientists thought giant lacewings had disappeared from eastern North America. However, scientists recently confirmed that one had been spotted.

Michael Skvarla works for Penn State University, who is the director of its insect identification lab. Skvarla found the giant lacewing in 2012. He remembers it clearly, “I was walking into Walmart to get milk and I saw this huge insect on the side of the building,” Skvarla said. “I thought it looked interesting, so I put it in my hand and did the rest of my shopping with it between my fingers. I got home, mounted it and promptly forgot about it for almost a decade.”

Then, in late 2020, Skvarla was teaching biodiversity in a Zoom class during the pandemic lockdown. During the class, Skvarla showed his students microscopic images of the insect he had seen at Walmart. Together, they stared at the images. They studied the insect closely. Then, they realized that the insect had been wrongly labeled. Many scientists are stirred by this discovery. Now they have started wondering if there may be entire populations hiding out, which requires for further investigation.

And the causes of the supposed disappearance of the insect have long been a mystery. With a deeper research, there are some possible explanations. One is light pollution, which is the brightening of the night sky from man-made light sources such as street lights. Light pollution can disrupt the natural cycles of living things. Another cause could be the introduction of non-native insects such as ground beetles. They can cause harm to the environment. Ground beetles prey on giant lacewings. People’s stopping forest fires may also play a part in the disappearance of the lacewing. This is because giant lacewings need ecosystems that rely on natural fires.

【推荐3】Why late-night eating is something you should absolutely avoid? It’s long been popular advice for people looking to lose weight to avoid late night eating. It’s no wonder, with a host of research showing that late-night eating is linked to greater body weight. But until now, few studies have actually investigated why. This is what a recent U.S. study set out to uncover.

Researchers had 16 participants follow two different meal schedules, each for a period of six days total. The first group had their meals early in the day with the last meal consumed six hours and 40 minutes before bedtime. The second group had their daily meals four hours later. This meant they skipped breakfast and instead had lunch, dinner and an evening meal. Their last meal was consumed only two and a half hours before sleep. All the participants consumed an identical diet, and all of their meals were equally spaced with around four hours between them.

The researchers looked at three measures associated with weight gain: the influence of appetite, the impact of eating time on calories burned, and changes of fat tissue. They found that compared to an early eating pattern, late eating not only increased feelings of hunger the following day, it also increased the rate of “hunger” hormones (激素) in the blood. Late eating also caused a decrease in calories burned the following day. Fat tissue samples taken from the participants also showed the increased fat storage. These results indicate that late eating could lead to weight gain.

Given the study was only conducted on a limited number of participants and over a very short time, more research will be needed to further understand whether these changes are only temporary, and what effects long-tern late-night eating can have on the weight gain mechanisms (机制).

Anyway this study adds to a growing body of evidence showing just how important meal timing can be when it comes to body weight. Therefore, people who are watching their weight may want to ditch the late-night snacks and favor eating most of their meals earlier.

【推荐3】Some of the most well-known bicycle friendly cities in the world are the ones going car-free like Copenhagen and Amsterdam but a lesser known city, Utrecht, the fourth largest city in the Netherlands, seems to be winning the competition hands down.

Today, with an average daily number of bike tips standing at 125,00 the city is doing something very right. A new short film by Streetfilms shows how this city of 360,000 — with 22.5 billion bicycles — transformed itself into a cyclist’s paradise.

Utrecht is made up of a historic city center, and bike paths and roads weave through the downtown making it really easy to commute to work or school without ever using a car. That’s because the city built specialized roads and bike parking facilities to give bicycle riders the upper hand over cars. According to CityLab, cars make up only 15 percent of the trips into the downtown area. Sixty percent are done by cyclists.

But the city wasn’t always this bicycle friendly. In the 1950s and 60s, cities in the Netherlands were as cities in the rest of Europe and the US. In the 1970s, in response to a rise in the number of pedestrians getting killed in traffic accidents, people started protesting against the use of the streets being priortized for cars. And the high cost of gasoline and the environmental movement added to conditions for change.

The transition didn’t come cheap. According to the New York Times, the city spends over €49 million annually to build, improve and maintain the bike-based transportation network which the city plans on doubling by 2030.

There are complaints by car owners that they are being discriminated against. “These are just growing pains.” Lott van Hooijdonk, the city’s mayor, said in the film, “The advantages of the changes far outnumber the disadvantages and include reduced air pollution, lower healthcare costs and a host of other social benefits. In Utrecht, two wheels are so much better than four.”