Why do ducks stand still in the rain when it rains? | Expo Daily

Why when it rains,

The duck just stood there in the rain without moving?

Why does the duck in the picture stand still in the rain? The reason is complicated. First of all, we need to know that duck feathers are waterproof. When rain falls on the duck's feathers, the water droplets will slide down the gaps between the feathers and will not wet the feathers.

The ducks we see usually fill their stomachs whenever they have the chance. If they can no longer eat, they will find a place to rest to save energy and stop all non-essential activities as much as possible. Rainfall may wash away food on the water surface, making it difficult to find food.

The result is that the duck may consume a lot of energy, but find little food. At this time, it is a good idea to "lie down" and rest to save energy, which can avoid unnecessary energy waste and reduce physical consumption. This strategy of saving energy is beneficial for ducks, especially when food is scarce or the environment is harsh.

In addition, rainfall is often accompanied by meteorological phenomena such as strong winds, lightning, and thunder. Most water birds are not good at walking on land. It is not a good idea to move at this time. They may be blown down by the wind and injured.

The situations mentioned above are often the way ducks and other water birds deal with light or moderate rain. However, if they encounter extreme weather such as heavy rain or rainstorms, water birds will also look for sheltered places to hide. Even if their feathers are waterproof, it will be of no help when encountering heavy rainstorms.

Source: Screenshot of TikTok video

Is olive oil the best oil or just a waste of money?

One of the important reasons why olive oil has a long-standing reputation and is often said to be the best cooking oil is the Mediterranean diet.

The Mediterranean diet is often called the "healthiest diet" and has even topped the list of a certain foreign rating website for seven consecutive years. The typical feature of the Mediterranean diet is eating olive oil.

In fact, there have been studies that have analyzed several common dietary patterns, including the Mediterranean diet, DASH diet, low-fat diet, low-carb diet, Paleolithic diet, etc., to analyze their effects on health. The results show that although the effects of different diets on human health are different, there is not much difference overall.

In fact, whether a diet is healthy or not mainly depends on the food combination of people, not entirely on a certain diet or certain foods. Therefore, the Mediterranean diet is not healthier, and it is obviously untenable to say that olive oil in this diet is healthier.

In general, olive oil is a vegetable oil rich in oleic acid and low in saturated fatty acids. It is a relatively good cooking oil, but it does not have a significantly higher nutritional value than other vegetable oils. It is indeed an exaggeration to say that it is the "best cooking oil".

Of course, olive oil also has an advantage - it is relatively expensive, and people usually don’t want to eat too much of it, so it can help us reduce oil intake.

Image source: pixabay

The real "shit mountain code" is coming.

It keeps stuffing garbage in it...

A lungfish from the Americas has the largest genome of any animal ever found. At 91 billion bases, it is 30 times larger than the human genome, according to a study published in Nature.

However, these 91 billion bases only contain the same number of genes as humans - about 20,000, and the rest is non-coding DNA or may even be "junk" DNA.

The vast majority of the American lungfish genome is made up of something else — repetitive segments called transposable elements, which can replicate themselves and insert those copies into the DNA.

How did the lungfish genome become so messed up by repetitive DNA? The researchers found that its growth was uncontrolled because the lungfish in South America and Africa had lost some key genes whose RNA and protein products could inhibit transposable elements.

All but one of the lungfish's 19 chromosomes are as large as the entire human genome, so copying that DNA takes a lot of energy, and the nucleus and cells that house it are also larger.

It is not clear why the American lungfish has not evolved new ways to control the spread of these so-called "jumping genes." Failure to regulate genes that ensure the viability of an organism could also become a "sword of Damocles."

South American lungfish

Image credit: Katherine Seghers, Louisiana State University

Goats' eyes are like panoramic cameras

Goats are a common animal in nature. Their pupils are rectangular, which gives them a field of vision of about 300 degrees. Not only can they detect danger more promptly, but when being hunted by predators, such eyes can also help them see the terrain better. In addition to sheep, horses and deer also have the same eyes.

Can artificial starch be eaten?

The original intention of the artificial starch synthesis project was to transform the agricultural process of starch production into an industrial process. We call this paradigm shift "agricultural industrialization."

In three years, the research team achieved the artificial synthesis of starch from scratch, and it took nearly another three years to increase the starch synthesis capacity by 136 times.

Many people have asked, can we eat artificially synthesized starch? Cai Tao, a researcher from the Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, answered in Gezhilundao: We can’t!

Because the starch synthesized in the laboratory is only about 1 gram, it is not that we dare not eat it, but we really can't bear to eat it. The next task is to accelerate its industrial application.

In this process, it is not just a simple scale-up, but also some basic scientific problems in the whole scale-up process need to be solved. In the future, if we can produce kilograms or even tons of starch, then we can answer this question.

The content is compiled from China Science Popularization Expo Weibo, Science Popularization China, Science Rumor Refutation, China Science Daily, and Gezhi Lundao Forum

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