Section V Threats of Laws of Evolution
I. Heredity, variation and evolution
A man can produce sperm, sperm cell, a woman can produce eggs, and the egg is the cell, when a sperm cell combines with an egg cell, and a new cell will be formed, which is fertilized. As a fertilized egg cell can be split into two completely consistent with their own cells, the cells of the two split their further split into four cells of exactly the same as their own, and then split into four and eight, it is so time and again split, and finally the formation of a living person.
Could be interpreted to mean the formation of life is the result of cell division, is the case, no true biological. So why do people have their own different, individual animals differ, each plant so strange? The decided biological characteristics hide in the internal biological cells.
In the cell there is a material known as deoxyribonucleic acid, or DNA, it is the basic unit for DNA, the genetic code of life is found in DNA. Simple division, cell structure from the peripheral cytoplasm and central nucleus of the composition, in the nucleus there is a very important material, which is the chromosome. Chromosome is a DNA carrier, which always appear in pairs, half from the male parent, half from the female parent, so half of the life traits of the decision by the male parent, the other half of the decision by the female parent. We are a total of 23 pairs of human chromosomes.
DNA molecule is composed of two long-chain structure of the double helix, like a twisted spiral ladder with handrails of the ladder by the composition of phosphoric acid and deoxyribose, which is the backbone of DNA, cross-files by the base pairs the composition of the genetic code of life on the cross carved on the ladder file. We usually decide what characters to life the "gene" is all the DNA fragments. Human Genome Project in accordance with the preliminary results, it is estimated that there are human genes 30000-35000.
DNA double helix of two long-chains, its structure is entirely consistent, but the direction is reverse, that is, both the two chains is the reverse, they were entangled with the right hand spiral. When in the cell division, DNA molecules of two separate long-chain removed, the formation of two separate chains, each chain with the other pair to form DNA, the formation of a new double helix, the new dual - screw with the original double helix is fully consistent, which will have two exactly the same DNA with the original DNA molecule, which is self-replication of DNA.
We say that the self-DNA replication, the newly formed double helix with the original double helix is the same, so that a copy of the results of almost 100% accurate. However, all things are not foolproof, as many times in the copy in very occasional errors in copying, which is called "mutation."
We sometimes found in pastures, cattle, sheep baby occasionally produced a hybrid variation of this is the animal. In cropland, the one occasionally found in different crops Miller, this is variation. This phenomenon will also appear in humans.
In fact, all biological phenomena are variations, some to the next generation of genetic variation can, and some are not genetic. Most of the biological variation of a bad thing, it generates the individual than the normal individual poor viability. For example, we are talking about cancer, the body cells is the event of adverse results of variation; we are talking about radiation sickness, is a high-energy rays penetrate the nucleus, DNA damage in the structure of the nucleus, resulting in variation of results.
Variation in the biological, there will be a great chance not only to the viability of individual variation is not bad, but stronger, if this mutation can be genetic, more viable groups will be formed, which is what we call evolution. Earth from the most primitive early life, the development of all living things contends vitality is the result of evolution; we humans are also a product of evolution.
Biological evolution also has the reverse situation, that is, a negative variation as a universal biological phenomenon, but this can also be genetic variation. This situation can also be referred to as degradation, degradation will lead to the species become increasingly unsuited to the environment, more and more not survive and, after a period of struggle and will be extinct.
Are in the evolution of any species, and in accordance with the views of the theory of evolution, all living beings on Earth are from the same ancestors, as a result of this primitive life in a different environment, different variations have occurred, so differentiation of animals, plants and fungi. These continue the evolution of life, strong who survive, the weak are eliminated from this rule has been referred to as "natural selection, survival of the fittest," or as the law of natural selection, and this is one of the most important evolutions of the law.
II. Species extinction causes
The world's biological species recorded about two million kinds of animals, 270,000 kinds of plants, 35,000 kinds of microbes, together with the record has not the species, scientists estimated that the total number of biological species should be as high as 1-30000000 kinds . However, the existence of the planet has been much more than this species, the basic can be sure, today the number of species on Earth has existed for less than 1% of number of species, while the other 99% of the species are already extinct.
The last of the mass extinction of life on Earth are the result of leading the forces of nature. Life on Earth has existed for about 38 million years, during which despite a number of large extinction, however, life has never been interruption. From the Cambrian explosion, the earth experienced five extinctions, the largest mass extinction occurred in 2.5 billion years ago at the turn of the Permian and Triassic, when 90% of the aquatic organisms and 75% of terrestrial plants and animals disappear, and this also shows that the extinction of the incident there are a number of species preserved.
This shows that the earliest life on Earth has its own, has never been the deterioration of their environment to enable all of the organisms can not survive here, even in the bio-mass extinction period, only part of the biological environment can not meet at that time.
Through the study of species extinction, the extinction of species can be drawn a total of three Su-a result of escape:
1. Environmental factors
Environmental factors are the change as a result of the natural environment led to the extinction of species. Earth's environment by a variety of factors, such as volcanoes, asteroid or comet impact, magnetic disappeared, the cyclical nature of global climate cooling or heating, etc., which are the Earth's environment can change a lot. Changes in the environment, a number of biological itself will be able to adapt to the new environment, although there are biological and can not adapt to the new environment, but the slow process of change in the environment, make a corresponding adjustment to the environment evolution, it will be able to survive the biological . If the above two conditions are not met, this is bound to the extinction of species.
Environmental factors are the most important factor in the extinction of species, especially large-scale mass extinction of the role of environmental factors become more prominent. In the five mass extinction of biological research found that every time the main reason for mass extinction is to environmental factors, that is, changes in the natural environment.
Great changes in the natural environment led to the extinction of the cluster is a very good understanding of its causes, because in general the biological body are exposed in their natural environment is very sensitive to the natural environment, the natural environment will inevitably lead to a large part of the biological changes can not adapt to the new environment, especially in the case of drastic changes in the environment of its more prominent role in extinction.
2. Species competition
Competitive factors in a broad sense are a kind of species to environmental factors. Species refers to the strong competition is eliminated species caused the extinction of vulnerable species, or because of the interdependence of the reduction and extinction of species caused the extinction. Competition of species, including interspecies’' competition, leads to the extinction.
Species, the role of competition generally conventional extinction, will not lead to the extinction of the cluster.
3. Species degradation
Broadly speaking, the same species, the degradation of factors may be brought into the environmental factors. Species refers to the external environment degradation has not changed, or is likely to be affected no change in the survival of species, but some species, there were not conducive to continue to survive in this environment variation, and this adverse variance is genetic, and the overall variation in this species.
When a species is a degradation of an irreversible trend, this species will be increasingly difficult to survive, to have been eliminated and, ultimately, the disappearance of extinction. Species degradation generally works on the conventional extinction.
III. Threat of laws of evolution
Role in the evolution of the law of any species, including human beings, all species are relentless in the evolution of the law, and there appeared to eliminate the phenomenon of living, it does herald the end of mankind would be the role of the forces of nature to the extinction of this?
1. Environmental threat
General biological approach to adapt to the environment is very simple, completely exposed as a result of the state, if the global climate cooling, the evolution of animals is certainly the direction of thickening skin, long hair; if global warming, animals must be the direction of the evolution of skin thinner, shorter hair, if this kind of evolution can not be completed will be extinct.
At the same time, food chain relationships between species, will inevitably lead to the extinction of a species as a group of food reduction and extinction of species. Because the animals the way of food processing chewing mouth only, it is impossible not to eat some species can become fit for human consumption, although the evolution of the digestive system can also, but to complete this evolution only a small number of species; the way to access to food animals is a simple gift of nature, it is impossible to carry out domestic and domesticated food, some changes in the nature of animal food to obtain the impact will be great.
Humans have fundamentally from the situation of animals, because human intelligence has reached a commanding height of an absolute, and any species have mastered the science and technology to catch up, thus, human beings and the natural environment is taken to deal with an entirely different approach.
Human being has been completely exposed from the body must rely on the natural environment to adapt to changes in the situation, which as early as anthropology in a number of years before the animal will put on his body, the use of fire to heating has been on fundamental changes. Today, however, very optimistic about all the more, we can adapt to changes in outdoor temperature clothes changes in the interior is through the stove, heating and air-conditioning temperature, at very high or very low temperature environment can be designed special work clothing and facilities.
And from an environmental impact on human food, the rough calculation, we have the advantage of any animal is second to none. As early as millions of years ago human beings will be able to use rock smash the nuts feeding, and then learn how to use fire, so that food can not be eaten raw can be made fit for human consumption, Ten thousand years ago mankind learned how to domesticated poultry, domesticated plants , which has far more than other animals.
However, not all this long ago compared with today's human beings, we can through the greenhouse in the winter cold to eat a variety of fresh vegetables, fruits and grain; we can change the genes of crops, cultivate a cold, anti-heat, drought, flood, disease and pest resistant crops; As the consumption of a variety of animals in captivity, but also for those of poultry, livestock, enjoy the summer shade and winter warmth.
At the same time, we can see that the human species are miscellaneous food, plants and animals can become its food, raw and cooked food can be accepted, which makes human beings in response to changes in the natural environment, in the face of their own food all the more able grasp.
In that case, whether the environmental change on human not a decisive influence on it? Of course not, in fact, the preceding sections of this chapter discussed most of them are related to human impact on the environment, the threat of the universe, the solar system, as well as the threat of a threat to Earth, all of mankind is the threat posed by the basic threat to the environment . However, can lead to the extinction of the human environment of the overall threat, must be sufficient to lead to global ecological suffered a complete collapse of the power, and far from the ordinary sense of the environment. In that case, a recent human use today are genuinely unable to grasp the means to escape the threat of extinction, that is, the sun turned into a red giant, however, it is a very distant threat, the threat today is considered too early.
2. Species competitive threat
The dinosaur had a strong long-term rule of the earth, we may as well make the assumption that, if today, on Earth at the same time the survival of humans and dinosaurs, dinosaurs rule is the rule of human or human dinosaurs do? I think the answer is very clear, must be the wisdom of a huge dinosaur of human rule, and not the opposite.
A person who single-handedly not encountered in the field of dinosaurs, even if the wolf encounter, I am afraid it will be shredded. However, groups of human beings, especially the high-tech means to master a high degree of human wisdom, its power is unparalleled peak.
Can be sure, today's competition for survival of any species in the road to extinction of the population can reach more than 60 million human beings, from the evolutionary point of view, the human will never allow any other species in the evolution of the development of enough the overall survival of their own as a threat to the point where enough. This is a threat to plants and animals is to say the least, because of animals and plants on Earth are in control of human being, perhaps of their development and changes of small and even larger changes in human development and are difficult to detect, but the development and changes can be as large as the larger threat to the survival of mankind when mankind will be found in the human by virtue of its powerful forces are fully capable of controlling its development.
The threat of biological evolution is the most difficult control of micro-organisms, this is because very small micro-organisms, and the number of extremely large, a new virus and bacteria can surprise attack humans, and the most frightening is that the vicious infectious diseases.
However, today we have a means of diagnosis and treatment of infectious disease prevention and control, the total can be controlled within a limited scope, and not to suffer too much for human being.
Such kind of ability is based on facts. The late Middle Ages in Europe the Black Death had killed half of the urban population, but Milan is from the catastrophe, as bishop of Milan command, where there is a disease, whether dead, live, are surrounded by walls of its housing, and are buried. After the science developed after the effective way to know is that isolation is to prevent epidemics of the most effective means.
In 2003, in China, the explosion of a highly contagious, high mortality rates of malignant and infectious diseases SARS, developed as a result of traffic, only 2 months to spread the disease to more than 30 countries on five continents, it is On the mere mention SARS. However, countries should adopt effective means of inspection and quarantine in and there is no effective drug therapy, the only five-six months to curb the spread of SARS, the final transmission of less than 10,000, fewer than 1,000 deaths. If this should be in 100 years ago, the harm will be thousands of times more than today.
In fact, we have antibiotics and other drugs to treat a large extent, is already available in a wide range of new diseases. At that time, the treatment of SARS is completely taken stop-gap solution, although not as much special effects, but also to the emergency. It can be sure that we have mastered the above-mentioned modern means of micro-organisms through the evolution of the disease though will surely bring to the human death and harm, but not the extinction of mankind.
3. Species degradation threat
Degradation of the species here refers to the degradation of human beings, that is, human will can not be resisted because of their genetic variability, degenerate into something totally inappropriate to continue the species to survive, resulting in the extinction of this? For example, can not continue to multiply; become more and more stupid or intelligent, and finally evolved into the same general animal species, and therefore extinction; or else there are not conducive to continue to survive the degradation and so on.
In accordance with the principles of the theory of evolution, the use of the organ will be more evolution of the more developed is the only major human brain to adapt to the environment with the biological, because of the large-scale use of the brain, human intelligence is bound to become increasingly developed, the conclusion from the theory are totally dependent on support. And in terms of creativity, in fact, human creativity has been the increasing trend in the past; still do not see any signs of stagnation and retrogression. As long as there will be no major intellectual degradation, human beings on the earth is perfectly placed to continue to dominate, and they are better than other species to adapt to various environments.
In fact, even in case of a human in the next day, the degradation of intelligence there, and even the many important aspects of physical degradation are not terrible, as far as today we have the basis of gene technology as recycling, as long as a little development, can save his own human being. Recycling so-called gene technology is the use of enzymes to DNA on the gene cut, paste and repair, which in accordance with the wishes of their own to create their own request in line with the biological. At present, this technology has been widely used, scientists can cotton into red, yellow, brown; can produce seedless watermelon and seedless grapes; can grow frog eyes 6; can not long rat tail. All these are the results of genetic reconstruction.
As long as the wish, the human is entirely possible in the near future on their own genes for recycling. In particular, we have seen today, the Human Genome Project is to human DNA of the three billion base pairs and the composition of more than 30,000 genes to conduct a comprehensive study, sorting, and preliminary results have been achieved in the near the future will be all of human gene structure, as well as representatives of human life entirely to find out the password. So, on this basis as long as a little effort, it can be, human beings easily recycled.
We are very pleased to see that only human beings have a variety of today's technology, it has been successfully saved many endangered species. For example: British scientists launched a frozen storage of the DNA of endangered species programs; Chinese scientists on the endangered yew plants to cultivate a successful and succeeded in protecting the endangered species of giant pandas and so on.
One thing is clear, any variation of species, will not jump at the same time, the overall mutation, if one day find their own human being is really the beginning of the degradation of genes, are fully capable of relying on already mastered the technology of biological engineering, the successful to prevent the spread of this negative variation, but also the completion of the work plan. Therefore, the species can not lead to degradation factors of the extinction of mankind.
To sum up, till the evolution of sun into the red giant in 5 billion years, no extinction factors exist in nature. Thus, seeing from the opportunity given by nature, human being has an extremely long future, which can also be concluded from the survival history of other species. For example: 6500 years ago, dinosaurs existed sixteen million years on the earth due to its strong power. Human being is much more powerful than dinosaurs. Intelligent human being doesn’t need any more to confront nakedly natural climate changes, or struggle single-handedly with beast. The access to food is no longer simply relies on nature, but mainly on creative actions. It’s evident that human being is more powerful and stronger than dinosaurs to possess more survival abilities. In addition, human uses only 50 thousands years for evolution, at beginning of its history if comparing with dinosaurs. So even with simple logic reasoning, we can conclude that the human being will have millions and millions years of future.