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Crisis of balance between biology and environment
The history of life on earth is the history of interaction between living things and their surroundings. To a large extent, the physical form and habits of the earth? Plants and animals in America are shaped by the environment. Considering the whole time span on the earth, the opposite effect, that is, life actually changed its environment, has been relatively slight. Only in this century, a species of human has gained great power to change the nature of its world.
In the past quarter century, this power has not only become more and more powerful, but also its nature has changed. The most worrying of all? The destruction of the environment by human beings is that the air, land, rivers and oceans are polluted by dangerous and even deadly substances. This kind of pollution is largely irreversible. In the current widespread environmental pollution, chemicals are evil partners of radiation, which have changed the nature of the world and life. Chemicals sprayed on farmland, forest or garden stay in the soil for a long time, enter the living body, and pass from one living thing to another in a series of poisoning and death. Or they mysteriously pass through underground streams until they appear and combine into new forms, killing plants, making cattle sick and causing unknown harm to people who drink once pure well water. As a scientist said, "man can't even recognize the devil he created."
It took hundreds of millions of years to produce life that now lives on the earth. Given time is not in years but in thousands of years, life will be adjusted and balance has been reached. But in the modern world, there is no time.
The speed of change follows the pace of human impulse, not the leisurely pace of nature. Radiation is now an unnatural creation of human beings? Tamper with atoms. Chemical substances are the products of human synthesis? He has a creative mind and has no counterpart in nature.
It takes more than a few years to get used to these chemicals. Life, but the life of several generations. Even if there is a miracle, it will be in vain, because new chemicals keep coming out of our laboratory; In the United States alone, nearly 500 sets are put into practical use every year. Many of them are for human beings? War with nature. Since the middle of 1940? More than 200 basic chemicals have been invented to kill insects, weeds and other creatures called "pests".
I don't think chemical pesticides must not be used. I really believe that we have indiscriminately handed over toxic and biologically effective chemicals to those who are basically or completely unaware of their potential harm. We expose a large number of people to these poisons without their consent, and often without their knowledge. In addition, I think that we allow these chemicals to be used, but there is little or no prior investigation of their effects on soil, water, wildlife and human beings themselves. We lack attention to the integrity of the natural world that supports all life, and future generations are unlikely to forgive us.
The history of life on earth has always been the history of interaction between organisms and their environment. To a great extent, the shapes and habits of animals and plants on the earth are shaped by the external environment. Considering the whole time of life on the earth, the opposite effect, that is, the actual change of life to its surrounding environment is relatively small. Only in the current century (referring to the 20th century) has a species emerged-human, which has gained great power and changed the natural state of the world in which it lives.
In the past1/4th century, this power has not only become stronger, but also its nature has changed. Among all kinds of human actions to destroy the environment, the most worrying thing is that human beings discharge dangerous or even deadly substances into the atmosphere, soil, rivers and oceans, and today's pollution is largely irreversible. Today, with the widespread environmental pollution, chemical substances collude with radiation, changing the natural state of the earth, that is, changing the natural state of life on the earth. Chemicals sprayed on farmland, forest or garden stay in the soil for a long time, penetrate into the organic body and transfer to each other, forming a chain of poisoning death. Chemicals also spread mysteriously through groundwater, and finally appear and combine in new forms, poisoning plants, making livestock sick and causing unknown harm to people who drink once pure well water. As a scientist said:? Humans don't even know the demons they created. ?
It took billions of years for the earth to create the life that lives in it. After a certain period of time-not a few years but thousands of years-life begins to adapt to the environment and form a balance with it. But in the modern world, time has passed.
The speed of environmental change no longer obeys the leisurely rhythm of nature, but obeys the urgent and hurried pace of human beings. Radiation is an unnatural creation that human beings get by controlling atoms today. Chemical substances are the synthetic products created by human creative thinking, and there is no corresponding thing in nature.
In order to adapt to these chemicals, it takes not only a lifetime, but several generations. Even so, even if miracles are possible, this adaptation is futile, because new chemicals are pouring out of our laboratory. In the United States alone, about 500 kinds of chemicals are put into use every year, many of which are used in the war between human beings and nature. Since the mid-1940s, human beings have created more than 200 basic chemicals to kill insects, weeds and other so-called? Pests? .
I'm not saying that humans must not use chemical pesticides. What I want to say is that we indiscriminately give these toxic chemicals with powerful biological functions to those who basically or completely don't know the potential harm of these products. We expose many people to these toxic substances without their consent and often keep them in the dark. I would also like to say that we allow the use of these chemicals, but there is little or no prior investigation on their effects on soil, water, wildlife and human beings themselves. Our descendants can't forgive our lack of attention to the ecological unity of nature on which everything depends.
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Can genetic technology make people smarter? Be smart
Many people dream of having a smarter brain. Joseph Z. Tsien, a neurobiologist at Princeton, found the answer. In September, he announced that he? D made a better mouse by changing a gene that affects learning and memory. One day, similar genetic manipulation processes may be used to improve human intelligence.
The secret lies in a feature of brain cells called nmda receptor. Qian Cunxun compared [1] to a cylindrical tube or window that regulates information flow. When the window is open, chemicals called neurotransmitters can easily pass through and memories are recorded and stored. But as the organism matures, this window begins to close. This may explain why children lose the ability to learn new languages when they are sexually mature, and why some people lose their memories as they get older. )
Qian Cunxun noticed that when the receptor was combined with NR2B gene, the work efficiency was higher, so he introduced additional NR2B gene into a batch of fertilized eggs. In a normal mouse, the opening time of the memory window is only one thousandth 150 second. In money? In specially modified mice, the window opening time is 250 thousandths of a second, which is enough to make a significant difference in memory retention. When he let his mice compete with ordinary mice, they won. Ordinary mice can recognize a Lego block 12 hours, but smart mice can remember this block for three days. "That? "This is a profound progress," Qian said.
Can humans do it? Maybe, but genetic engineering must first make some extraordinary progress. Some thorny ethical issues must be solved. At the same time, Qian Cunxun promised to lock his furry little geniuses in the laboratory, away from your storage room. "Otherwise," he said, "you may need a clever cat or a clever mousetrap to catch them."
Many people wish they could become smarter. Joseph Z. Tsien, a neurobiologist at Princeton University, discovered the key to wisdom: in September, he announced that he had bred a clever mouse by changing genes that affect learning and memory. Similar gene processing technology is expected to be applied to the human brain in the future, which will promote the leap of human wisdom.
The mystery of this technology lies in the function of brain cells called nmda receptors. Qian Cunxun compared it to a cylindrical channel or window that transmits information flow. When the window is open, a chemical called neurotransmitter can flow easily, so the memory is registered and stored. However, when the organ matures, this window begins to close. This can also explain why children will lose the ability to master new languages when they grow up (when their sexual organs are mature), and why some people will lose their memory when they are old.
Qian Yongjian pointed out that when receptors cooperate with a gene called NR2B, their efficiency will be higher. Therefore, he implanted the NR2B gene into the fertilized eggs of a group of mice. The memory window of an ordinary mouse only opens 150 seconds. However, the memory window of mice implanted with money gene can be opened for 250 thousandths of a second, which has been able to make amazing changes in their memory. When he lets his mice fight ordinary mice, they can easily win. Ordinary mice can keep the memory of Lego bricks 12 hours, while smart mice can keep the memory for three days. ? This is a far-reaching progress. ? Money says so.
So, can humans accept this kind of gene transplantation? Maybe, but the premise is that genetic engineering must first make extraordinary achievements and solve a series of thorny ethical problems. Qian Cunxun promised that he would lock those little geniuses in fur into the laboratory and stay away from people's food cabinets. ? Otherwise,? He said,? In order to catch them, people have to look for smarter cats or more powerful mousetraps. ?
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Is it safe to eat genetically modified food? Food that can be eaten safely?
Traditional plant breeding includes crossing different varieties of the same species by natural hybridization. For example, disease-resistant wheat varieties have been crossed with high-yield wheat, combining these characteristics. This natural gene exchange is safe and quite predictable.
Genetic engineering (GE) involves exchanging genes between unrelated species, which cannot naturally exchange genes with each other. Genetic modification may involve gene exchange between different species, such as inserting scorpion toxin gene into corn or fish antifreeze gene into tomato. A scorpion toxin gene, even if it exists in the DNA of corn, may make organisms produce scorpion toxin ―― but what other effects will it have in this strange environment? We have seen this problem-adding human growth hormone gene to pigs will certainly make them grow-but it will also bring them arthritis and make them cross-eyed, which is totally unpredictable.
For example, it is obvious that if the human intelligence gene is inserted into the DNA of cabbage, its effect will not be the same as that in human DNA ―― but what side effects will it have? In other words, are genetically modified foods safe to eat? The answer is that no one knows, because there is no long-term test.
Companies wishing to obtain approval for genetically modified products in Britain or the United States need to provide their own safety test results to regulators. Monsanto? Before it was approved, American soybeans had obviously been fed to fish 10 weeks. There is no requirement for independent testing, long-term testing, human testing or specific risk testing for children or allergic people.
The current position of the British government is. There is no evidence that genetically modified foods will cause long-term harm. ? In the United States, the US Food and Drug Administration is currently being sued for covering up research suggesting that genetically modified foods may pose risks.
The traditional method of plant cultivation is to artificially hybridize the same species according to the natural hybridization of plants. For example, disease-resistant wheat crosses with high-yield wheat to form a new wheat variety with dual characteristics. This natural gene exchange is both safe and predictable.
Genetic engineering is the exchange of genes between unrelated species that cannot be exchanged under natural conditions. It can exchange genes between very different species. For example, scorpion toxin gene is injected into corn, or fish antifreeze gene is injected into tomatoes. Even in maize DNA, scorpion toxin gene may still be obtained from organic tissues to produce scorpion toxin. But in this heterogeneous environment, will this gene product have other functions? In fact, we have found this problem: transplanting human growth hormone gene into pigs will definitely accelerate the growth of pigs, but it will also cause arthritis and esotropia in pigs, which is completely unpredictable.
For example, the role of human intelligence genes in human DNA and Chinese cabbage DNA is obviously different. But what are the side effects of implanting Chinese cabbage? In other words, is it safe to eat genetically modified food? No one knows the answer, because people have not conducted long-term tests.
In Britain or the United States, if a company wants its genetically modified products to be approved, it must provide the safety test results of its genetically modified products to the regulatory authorities. Before Monsanto's soybean was approved, it took 10 weeks to feed the fish. At present, there is no requirement for independent testing, long-term testing and human testing of genetically modified products, nor for testing the specific dangers they pose to children and allergic people.
What is the current attitude of the British government? There is no evidence that eating genetically modified foods is a long-term danger. ? In the United States, people are suing the US Food and Drug Administration for covering up the safety research results of genetically modified foods, which show that eating genetically modified foods may lead to danger.