The earth is the only common beautiful home for human beings. Since human beings have become the senior overlord at the top of the food chain, many animals and plants are on the verge of extinction every year. Especially in the 1990s, amphibians all over the world began to appear unexplained death, especially in the Central America, the Caribbean and Australia The most serious.
The picture shows a large number of dead amphibians in the area
Amphibians appear a large number of deaths, what is the truth behind the strange appearance?
With the development of human social activities and the change of ecological environment, large-scale animal death has become the most strange phenomenon in nature. In a large number of animal deaths, many people wonder what diseases make thousands of animals die collectively? The picture of a group of whales dying on the beach is chilling. More than 50000 cats jumped into the sea and killed themselves in Japan The reason behind the massive death of animals is frightening. As an ancient amphibian, frogs are now experiencing “doomsday crisis” all over the world, and more and more amphibians are disappearing.
According to an article published in the proceedings of the National Academy of Sciences, amphibians and fish will be the first to suffer in the sixth mass extinction of the earth, not small insects, nor the largest creatures like big cats, elephants and giraffes. According to the assessment provided by the scientists in the article, small frogs and other amphibians weighing less than one gram will disappear in the next few decades.
The picture shows the death phenomenon that began to appear in 1993
The mass extinction of amphibian “frogs” caused by Ranunculus
Since 1993, amphibians represented by frogs have died in large numbers, and the mysterious extinction event has attracted the attention of biologists. It was not until the end of last century that biologists found that the real culprit behind it was frog fungus carried by Xenopus laevis. According to the research of biologists, it is speculated that the extinction of 200 species of frogs may be caused by the frog pot fungus, and this number is far more than that.
A new report recently published in the Journal of science points out that the population of more than 500 amphibians has decreased significantly due to the influence of Ranunculus. Among them, 90 species have disappeared completely. In other words, in the amphibian community, the frog pot fungus completely set off a bloodbath. It is the biggest threat to amphibians, and this fungus is very cruel to kill amphibians and frogs.
The picture shows Xenopus laevis and Ranunculus
Some netizens can’t help but ask: “what is frog pot fungus? What about killing a lot of amphibians? ” Ranunculaceae is a kind of fungi, which belongs to the phylum Ranunculaceae. Its biggest characteristic is that it can not only live in the aquatic environment and soil, but also parasitize in animals and plants. For example, this kind of fungus exists in the body of frogs or other amphibians. Especially for frogs, the mortality rate of this kind of fungus is extremely high. Xenopus laevis is the natural host of Ranunculus. Ranunculus laevis can reproduce on the body of Xenopus laevis, but it is not fatal to Xenopus laevis. However, for other amphibians, it is not so lucky. Once the frog is infected with this fungus, a large number of molting will occur instantly. After the heart function is affected, it will eventually die due to cardiac arrest.
From 2009 to 2012, 99% of salamanders in Holland were killed by the fungus. Fire salamander is a kind of nocturnal animal, which likes to hide in dead wood. Sometimes when people take dead wood for fire, fire salamander will rush away, as if it was born from fire, so it is named fire salamander. It can be said that the emergence of chytra almost wiped out the Dutch salamander.
This is a salamander
The mass extinction of amphibians is related to human pregnancy test technology
In order to prevent the occurrence of mass extinction of amphibians caused by Ampullaria, biologists have carried out in-depth research on this fungus. However, in this study, biologists have made new discoveries. In the 1930’s, biologists first discovered that chytrium was found in the samples of Xenopus laevis, which is also known as “tool frog for pregnancy test” all over the world. Some netizens can’t help asking: is Xenopus a toad? No, it’s a rare creature in our daily life. Even many people have never heard of the name and know little about it.
Different from other amphibians, Xenopus likes to live in the still water area of tropical areas. In its visceral structure, the lungs of Xenopus are very large. This kind of lung helps the Xenopus float on the water surface regularly and breathe air. If there is a dry season, Xenopus can crawl along the short road to find another water source. Why has such an ordinary amphibian become a “victim” of human pregnancy testing technology? In this issue, a man played a crucial role. His name was Hogben. He was a very talented zoologist and worked very hard. In 1927, Hogben moved to South Africa. At that time, he carried out experimental research on amphibians here. Because the number of Xenopus in Africa was large, and it was a typical representative of amphibians, and it was very easy to catch them, so Hogben put them I put my energy on the Xenopus and regard it as my important research object.
Xenopus in hogburn experiment
In 1930, when hogburn injected Xenopus with the extract of hormone endocrine glands at the bottom of the brain of cattle, hogburn accidentally discovered that Xenopus began to lay eggs after being stimulated by this hormone. Through the occurrence of Xenopus, scientists also associate pregnant women, because pregnant women’s urine contains hormone hCG produced by pituitary gland, which can affect ovarian development. Scientists think that if the hormone in pregnant women’s urine is injected into Xenopus, will it also spawn as before, maybe they can be used as a living “pregnancy test stick”.
Based on this idea, hogburn led the team to carry out the experiment. He collected a woman’s fresh urine, extracted it and injected it under the skin of the female Xenopus. If this is a pregnant woman, the Xenopus will be stimulated by hormones to spawn. If this is not a pregnant woman, the Xenopus will not spawn.
The success of this experiment came out, known as the hogburn test. Since then, Xenopus has moved from Africa to all over the world, contributing to the reproduction of human beings.
Research and development of pregnancy testing tools: give women the freedom of reproduction, but also give women the freedom of life
Frogs bring devastating disaster
Hogburn brought some of the Xenopus back to China, and began to carry out pioneering experiments. Biologists have been doing pregnancy tests for the sake of human reproduction freedom, and they can’t extricate themselves happily. Since Xenopus was found to be able to become a “pregnancy test” tool, its fate has changed. From the 1940s to the 1960s, tens of thousands of Xenopus went to other continents, contributing their sperm and eggs to the development of human fertility “pregnancy test”, and becoming a new generation of pregnancy testing tools. Xenopus is famous for its “pregnancy test” and has become the most popular amphibian in the West. However, at the same time, it has also led to the transfer of chytra carried by Xenopus from Xenopus to almost all amphibians in the world, leading to the large-scale death of amphibians.
The history of human pregnancy test is long, and there are various methods of pregnancy test, and the biggest victims are animals
1. Barley and wheat seeds are also “pregnancy testing tools”
In the process of pregnant life, pregnancy test is an important link, and human beings have never stopped the exploration of pregnancy test. Before the invention of the “Xenopus” pregnancy test tool, human beings tried various methods of pregnancy test. For example, in Egypt, if women want to know whether they are pregnant, they can sprinkle their urine on the seeds of barley or wheat. If the seeds germinate, they will be pregnant. And there is also a more magical way spread in the local area, that is, if the barley sprouts, it means that the woman is pregnant with a boy; if the wheat sprouts, it means that the woman is pregnant with a girl. However, in the 1960s, some scientists thought that the accuracy of urine splashing on barley and wheat seeds to test whether there was pregnancy was as high as 70%, that is to say, this method was feasible. However, scientists expressed doubts about the detection of fetal sex.
2. Every year, 6000 rabbits fall victim to pregnancy tests
Scientists also carried out a “pregnancy test” experiment on rabbits. The researchers believe that if the pregnancy test is positive, the rabbit will die soon. For scientists, “rabbit died” is a pregnant good news. However, in fact, the scientists’ experimental method of cutting open the stomach is bound to make the rabbit die. This detection method is very effective Bloody and cruel, in order to improve the pregnancy test rate, every year researchers have to sacrifice 6000 rabbits for pregnancy test.
The picture shows the loveless rabbit
3. The color of the door bolt was observed by soaking
In the middle of the 15th century, a guide to women’s pregnancy was popular in Europe. In this guide book, it introduced in detail how to use a woman’s urine to soak in the door bolt for pregnancy test. The book pointed out that if there were traces of the door bolt in the basin after soaking for half a day, the woman was pregnant. So, we don’t know what principle this has to be based on.
The picture shows the history of pregnancy test
The successful invention of pregnancy testing tool is not only the gospel of the development history of human social activities, but also the tragedy of animals in the great nature. The fate of Xenopus is the result of human pursuit of scientific and technological progress. Although it is a world-famous “pregnancy testing tool”, this reputation is so unbearable. After all, the cost of species disappearance is too great.
For thousands of years, human beings have been marching towards the world. Every time they come to a new area, the species there are bound to be extinct. Especially in recent years, a large number of death monsters have appeared in amphibians. There is no doubt that this is the main cause of species extinction caused by human social activities. In the blue earth, with the accelerating speed of human social activities, the species that used to exist in the earth will disappear The animals who live comfortably have a sense of crisis of survival more and more. Many animals begin to die collectively. It’s not that they can’t adapt to the changes of the environment, but that they can’t accept the harm of human beings. Therefore, as human beings, we should understand that every species has equal rights to survive, and we should respect and treat life well!