Why do pandas have two "dark circles"?

Patterns on other animals have the same purpose.

This is determined by the genes of the organism. Is the result of long-term evolution. I like pandas.

Or because dark circles make its eyes look bigger, which is more deterrent to other animals.

Everyone knows the "clothes" of pandas. In addition to dark circles, ears, nose, mouth, limbs and other parts are all black, plus white, black and white contrast is sharp.

Why is there such a light and elegant dress? Why are pandas black around their eyes?

On the one hand, it is to adapt to the cold environment. Pandas live in high altitude areas, usually with long winters and heavy snowfall. In such cold weather, white hair is not enough. In the process of evolution, in order to protect the visual organs, there has been a "black eye socket" that everyone loves. Similarly, in order to ensure that chewing organs, olfactory organs, auditory organs and motor organs are not frostbitten, their fur color changes from shallow to deep, absorbing sunlight, just like people often wear dark clothes, dark earmuffs, gloves and knee pads in winter, which can reduce heat loss.

On the other hand, for self-defense and self-protection. The panda's dark circles are like wearing a pair of dark sunglasses. From a distance, they look like a pair of big bulging eyes, but the panda's real eyes are very small. Due to long-term living in the quiet environment of deep forests and bamboo forests, the visual range is limited, and the cool "dark circles" outside the eyes make the eyes look magnified countless times. If other animals look, they can't see clearly the size of their real eyes, which is enough to make the enemy "think twice before you act". However, this limited visual range and nearsightedness enable pandas to move after nightfall, because they have cat-like eyes and can adjust the changes of light at night. The black and white tones of the whole body shuttle in the snowy environment of alpine forests to adapt to the natural environment, and their clothes become protective colors.

In the long winter, all animals are short of food, and those fierce beasts are more difficult to hunt, threatening the animals in the neighborhood. Because of this kind of clothes, pandas are less threatened. This protective color, combined with the thick fur and a special layer of grease on the surface of the fur, makes the panda's clothes have thermal insulation effect and can sleep comfortably in the snow at night.

The world's first giant panda genome frame map is expected to be released this year, and the sequencing object is Jingjing, a giant panda in Chengdu Panda Base.

The world's first giant panda genome frame map is expected to be released. At present, the giant panda genome sequencing initiated and started by Chinese scientists is in progress. As the first sequencing object of the international "Giant Panda Genome Research" project, "Jingjing" lives in Chengdu Giant Panda Research Base. Yesterday, the relevant person of the base research center revealed the specific content of this work.

Uncover the "mystery" of dark circles

Why do giant pandas have dark circles? Why are there enzymes in the body that specifically digest bamboo? For these, Shen Fujun, director of the Chengdu Giant Panda Base Research Center, believes that all these are still a mystery to modern people. However, these secrets of giant pandas are expected to be revealed step by step through genome research. ? At present, scientists have only a preliminary understanding of the development details, nutritional balance, reproduction and disease prevention of giant pandas. This genome sequencing project can provide more scientific basis for these studies. In this project, Sichuan Wolong Giant Panda Protection Base also provided giant panda samples for the research project.

Shen Fujun believes that the international "Giant Panda Genome Research" project will provide scientists with a genetic and biological basis for a deeper understanding of this precious species. After the release of the frame map, many secrets of the giant panda's behavior, evolution, environmental adaptation, population isolation, migration history and so on may be revealed.

The new equipment is a frame diagram of "speeding up"

According to Shen Fujun, the giant panda genome is basically the same size as the human genome, and may contain 20,000 to 30,000 genes. Therefore, the international "Giant Panda Genome Research" project is also a huge project.

Shen Fujun revealed that in this project, experts introduced new instruments and equipment, which greatly reduced the workload. According to a preliminary estimate, the giant panda genome sequencing needs to invest 6 million yuan to 8 million yuan.

The international "Giant Panda Genome Research" is the first project in the world devoted to measuring genetic information to protect endangered species. Zhang, director of Chengdu Giant Panda Research Base, said that the international "Giant Panda Genome Research" project completely adopts a new generation of genome sequencing technology, which will not only greatly promote the progress of genome sequencing tools and technologies, but also have a far-reaching impact on many scientific research fields. At the same time, after the completion of the giant panda genome research, it will also provide an example for the research and protection of other endangered species in the world.

Giant panda (scientific name: Ailuropoda? Melanoleuca), also known as the Giant Panda in Taiwan Province Province, is generally called "Panda" or "Panda". It belongs to a carnivorous mammal in Xiong Ke, and its body color is black and white. Panda is an endemic species in China, and its existing main habitat is the mountainous area around Sichuan Basin in central and western China. There are about 1590 wild giant pandas in the world. Because of its low reproduction rate and high requirements for the living environment, it is listed as an endangered species in the Red Book of Endangered Animals in China and is the national treasure of China. Giant pandas are known as living fossils in the biological world because of their primitive characteristics [2].

The black and white fur color of the giant panda makes it deeply loved. 196 1 When the World Wide Fund for Nature was founded, the giant panda became the most important symbol of species protection. The giant panda is also an important representative of China's friendship in diplomatic activities.

The ancestor of the giant panda is the native panda (Ailuaractos? Lufengensis), which is the earliest carnivorous panda evolved from a bear-like animal. At first, the main branch of the panda continued to evolve in central and southern China. One of them appeared in the early Pleistocene about 3 million years ago and was smaller than the panda today. Judging from its teeth, it has evolved into an omnivore that eats bamboo. Since then, this main branch has spread to the subtropics, with a wide distribution, and fossils have been found in North China, Northwest China, East China, Southwest China, South China and even Vietnam and North Myanmar. In this process, the giant panda adapted to the subtropical bamboo forest life, gradually increased in size, and lived on bamboo. The giant panda reached its peak in the middle and late Pleistocene 500,000-700,000 years ago. Nowadays, the molars of giant pandas are well developed, and their claws have a "thumb" in addition to five toes. This "thumb" is actually a specialized formation of a wrist bone, scientifically called "radial sesamoid bone", which mainly plays the role of holding bamboo. American biologist Stephen Jay Gould (Stephen? Jay. Gould)-wrote an essay about this, and later used panda's thumb as the name of an essay collection.

Giant pandas are fat and bear-shaped, but their heads are round and tails are short, and their heads and bodies are black and white. Its body length is about 120- 180 cm, its tail length is about 10-20 cm and its weight is about 60- 150 kg. The head is round and big, and the front foot has a sixth toe besides five toes with claws. The trunk and tail are white, the ears, eyes, limbs and shoulder blades are all black, and the abdomen is light brown or grayish black.

Giant pandas in Sichuan have big and long heads, small teeth, more like bears, black spots on their chests and white hair on their bellies.

The giant panda subspecies in Qinling Mountains has a round head, a small skull, big teeth, more like a cat, dark brown spots on the chest and brown hair on the abdomen.