Darwinism and Mendelianism began to merge, twenty years after Mendelian law was rediscovered. This time, the giant of science is not alone, but the stars are bright. Among these great scientists, the most important ones are British R.A. Fisher, J.B.S Hald and American S.Wright. They proved theoretically that Darwinism and Mendelianism not only do not conflict, but also complement each other. The evolutionary data obtained by biostatisticians who observe and study in this field can be deduced from the principles of genetics. On the basis of Mendelian genetics, natural selection can perfectly explain the adaptive evolution of organisms, without Lamarconism at all (Lamarconism has also been proved impossible at this time). Mendelian genetics is what Darwin dreamed of! These theoretical studies began at 19 18 and were basically completed in the early 1930s. 1930, Fisher published the genetic theory of natural selection. 193 1 year, Wright published Evolution in Mendel Population. 1932, Holden published Evolutionary Dynamics. These three classic works constitute the theoretical basis of modern evolution.
However, these theoretical studies involve complex mathematical calculations, which are beyond the understanding of ordinary biologists. Moreover, the theory without experiments is hard to be accepted by biologists. Therefore, their research work did not have much influence in the biology field at that time. Until another great scientist appeared in the field of biology. He not only has the patience to understand these complicated mathematical calculations, but also verifies them with experiments. He is an American geneticist of Russian descent, T. Dobzhansky. Dubzansky studied Drosophila genetics with Russian geneticist S. Chetverikov and immigrated to the United States in 1927 (two years later, his teacher was arrested by the Soviet government and his laboratory was closed). He cooperated with Wright and confirmed Wright's theoretical work with fruit flies as experimental materials. 1937, Dubzhansky published Genetics and the Origin of Species. In this most important book on evolution after the Origin of Species, Dubzansky unified the theory of natural selection and Mendelian genetics theoretically and experimentally, which had a great influence on naturalists and experimental biologists and stimulated biologists in various fields to devote themselves to the study of evolution.
The next decade will be a fruitful decade of modern evolution. Zoologist E. Mayr applied modern evolution theory to taxonomic research, and put forward a model for the emergence of new species under the conditions of geographical variation and isolation. Paleontologist G.G. Simpson's research shows that modern evolutionary theory can be used to explain fossil records, while botanist G.L. stebbins pointed out that the evolution of plants can also be explained by modern evolutionary theory. By the 1940s, modern evolutionism had been successfully applied to all fields of biology. 1942, Sir Julian Sorell Huxley (the grandson of thomas huxley, one of the founders of evolution) published Evolution: Modern Synthesis, which integrated the research results of modern evolution in various fields, so modern evolution was called "Modern Synthesis Theory", that is, neo-Darwinism. The final completion of this great comprehensive process was marked by the establishment of the "Committee on the same problems of genetics, taxonomy and paleontology" in Princeton in 1947. The thirty academic authorities who make up this committee represent different fields of biology, but they share the same view: the integration of Darwinism and Mendelianism.
Five, there is no endless evolution.
1944, O. T. Avery proved that DNA is genetic material. 1953, Watson and Crick put forward the double helix structure model of DNA, and biology entered the molecular age. The research of molecular biology has supplemented important new evidence for the scientific facts of biological evolution. It reveals the consistency of the biological world at the molecular level and proves the evolutionary proposition that "all creatures evolved from the same ancestor". At the same time, molecular biology provides a powerful tool for studying the process and mechanism of biological evolution. In the past, biologists could only determine the genetic relationship of various species through the study of paleontological fossils and the comparison of existing biological morphological structures, so as to draw a phylogenetic tree; Now, we can compare protein's amino acid sequences or nucleotide sequences of genes at the molecular level, which not only confirms the results of traditional biology in general, but also makes the description of phylogenetic tree more accurate and quantitative.
The development of molecular biology also makes the study of evolution face new problems. 1968, Japanese geneticist Gen Kimura put forward the theory of neutrality, arguing that at the molecular level, biological evolution is not affected by natural selection, but randomly mutates at a certain rate, which is neither good nor bad for biological survival. Kimura put forward this theory based on the protein sequence at that time. Since 1980s, the results obtained from a large number of DNA sequence determination show that the change of DNA sequence is more in line with the neutral theory. At present, the correctness and scope of application of neutrality theory are still inconclusive.
In the past, the result of natural selection was often thought to lead to the adaptability of biological species or groups, which was called "group selection". Since 1960s, biologists tend to think that "group selection" probably does not exist, and natural selection only produces adaptability beneficial to individuals, and biological individuals will not give up transmitting their genes for the benefit of species or groups, which is called "individual selection". In fact, Darwin himself was an individual choice theorist (although few biologists agreed with him at that time). He believes that social insects, such as worker bees that have lost their fertility, are not really "altruistic" but selfish, because every hive is a direct descendant of a queen bee and is actually an individual. In the study of sexual selection, we have encountered similar problems. Some biologists further believe that the action unit of natural selection is not an individual, but a more basic gene than an individual, which is the "selfish gene" hypothesis that has caused great controversy. This hypothesis was accepted by more and more people after selfish DNA and selfish genes were discovered in 1980s.
Biological evolution can be divided into three levels: micro-evolution (the change of gene frequency in biological groups), the emergence of new species and macroevolution (jumping from one type to another, such as fish to amphibians). Modern synthesis theory perfectly explains the micro-evolution and the emergence of new species, and holds that the results obtained from the study of micro-evolution and the emergence of new species can be further extended to the great evolution. However, some biologists are skeptical about this inference. They think that great biological evolution may have its own mechanism. According to their point of view, the emergence of new biological types is the result of gene mutation during the development of biological embryos. Small mutations in embryonic development can lead to great changes in adulthood. Recent developmental biology research seems to prove this point: if a gene is expressed slowly during embryonic development, the fin will become a limb. It can be predicted that with the development of developmental biology, more and more major evolutionary problems will be solved.
Evolutionary biologists are debating how to evaluate these new achievements. People who hold radical views believe that these achievements subvert the modern comprehensive theory and must be replaced by new theories. Modern comprehensive theory is also called neo-Darwinism, so these new theories, such as neutral theory, are also called non-Darwinism. In the view of conservatives, these new achievements have no essential conflict with modern comprehensive theory, and can also be integrated into modern comprehensive theory. In any case, the modern synthesis theory, which has been attacked since its establishment, is still the mainstream theory of evolutionary biology. Perhaps in the near future, there will be a "molecular synthesis" theory that integrates the research results of new disciplines such as molecular biology and developmental biology. The theory of evolution has been evolving since it was founded more than 100 years ago and will continue to evolve in the future. Evolution, evolution is endless.
Darwin gradually formed the theory of artificial selection by summing up the practical experience of breeding and his own scientific experiments.
[Edit this paragraph] Artificial selection theory
When Darwin studied the origin of livestock and crops, he first found that there were many varieties of each kind of livestock and crops. He believes that no matter how many species there are, there may be great differences between them, but they all come from one or several wild species. For example, there are many varieties of domestic pigeons (Darwin collected 150 varieties of pigeons at that time), but they all originated from one species, that is, wild rock pigeons; There are many kinds of domestic chickens, but they all come from the same ancestor, that is, wild chickens.
How are different varieties formed? Darwin believed that all kinds of domestic creatures were created by human beings through conscious selection. The so-called choice is that human beings keep the individual variation that meets the requirements according to their own requirements and hobbies, let them pass the seeds to the next generation, and eliminate the individuals that do not meet the requirements. Through the accumulation of heredity and variation, various varieties are gradually formed. In this way, the formation of new varieties includes three factors: variation, heredity and selection. Variation plays a role in providing material here. Without variation, there would be no selected raw materials. Selection keeps the variation that is beneficial to people and eliminates the variation that is unfavorable to people. Without choice, there will be no directional development of variation. Heredity plays a role in maintaining and consolidating variation. Without inheritance, there would be no accumulation of variation.
The establishment of artificial selection theory is very helpful for Darwin to further explore the origin of species, which reminds him whether there is a similar selection process in nature. Further research convinced Darwin that the origin of various species was also due to a selection process similar to artificial selection in nature. The theory of natural selection was thus established.
[Edit this paragraph] Biological evolution theory
Evolution for short is one of the most basic theories in biology. Evolution refers to the process of evolution and development, species elimination and species generation under the action of variation, heredity and natural selection. There is no life on the earth. Primitive life was formed about 3 billion years ago under certain conditions. Since then, organisms have evolved continuously, and today there are more than 6.5438+0.7 million species in the world. The theory of biological evolution was first put forward by charles robert darwin, and it was discussed in detail in his masterpiece The Origin of Species.
There are three classical evidences of evolution: comparative anatomy, paleontology and the law of embryo development recurrence.
Biological evolution can be divided into three levels: micro-evolution (the change of gene frequency in biological groups), the emergence of new species and macroevolution (jumping from one type to another, such as fish to amphibians). Modern synthesis theory perfectly explains the micro-evolution and the emergence of new species, and holds that the results obtained from the study of micro-evolution and the emergence of new species can be further extended to the great evolution. However, some biologists are skeptical about this inference. They think that great biological evolution may have its own mechanism. According to their point of view, the emergence of new biological types is the result of gene mutation during the development of biological embryos. Small mutations in embryonic development can lead to great changes in adulthood. Recent developmental biology research seems to prove this point: if a gene is expressed slowly during embryonic development, the fin will become a limb. It can be predicted that with the development of developmental biology, more and more major evolutionary problems will be solved.
[Edit this paragraph] The significance of the origin of species
An epoch-making work
It marks that the views of most learned people on the biological world and the status of human beings in the biological world have undergone profound changes in the 19 century.
Classic works that affect the historical process
One of the 10 books that shocked the world.
A masterpiece that has had a wide impact on the process of human development.
Classical translation that influenced modern China society.
1985 American Life Magazine selected the best books in human history.
1986 ideal books recommended by French reading magazines
1859165438+1October 24th, which is a very extraordinary day in London, England. On this day, many Londoners flocked to a bookstore to buy a newly published book. The first edition of this book, 1250 copies, was sold out on the day of publication.
This sensational new book is The Origin of Species, which is the first masterpiece of Darwin, the founder of evolution. The publication of this book, for the first time, established biology on a complete scientific basis, and overturned the theories of "creationism" and "species invariance" with a brand-new idea of biological evolution.
The publication of the Origin of Species caused a sensation in Europe and even the whole world. It dealt a heavy blow to the foundation of theocracy, and all reactionary churches and feudal literati were furious. They attacked Darwin's theory, calling it "blasphemy against the Holy Spirit", violating the "divine right of monarchy" and damaging human dignity. On the contrary, progressive scholars represented by Huxley actively promoted and defended Darwinism. The theory of evolution explodes people's ideological imprisonment, enlightens and educates people to liberate from the bondage of religious superstition.
Darwin's Origin of Species is of great significance, which can be used as a natural scientific basis for class struggle in history. Marx
1859 became the dividing line between the two "worlds" after the prehistory of science. The publication of the Origin of Species has brought about a revolution in biology, which is as significant and far-reaching as Marxism on the historical stage. Darwin was far away from the noise of big cities. He was preparing a revolution in his quiet manor. It is this kind of revolution that Marx himself prepared in the center of the world noise. The only difference is that the lever is applied to another point. -Liebknecht.
Darwin's dominant idea in the Origin of Species, that is, "natural selection", will certainly be accepted as a scientific certainty. It has all the characteristics of the great truth of natural science, changing from vague to clear, from complex to simple, and adding many new things to old knowledge. Darwin is the greatest revolutionary in the natural history of this century and even all centuries. -British botanist Watson
I don't think the style of the book Origin of Species is better. Can touch people who know nothing about this problem. As for Darwin's theory, I am prepared to go through fire and water. -British naturalist Huxley
[Edit this paragraph] Life journey
From the oldest single cell to the birth of human beings with complex life structure and thinking, in the long river of life of more than 3 billion years, from birth to extinction, from low to high, what kind of magical forces are promoting the evolution and development of organisms? For centuries, people have racked their brains to try to find a convincing answer, and the results are puzzling.
Just as people hold different views on the mechanism of life evolution, and various schools and factions are arguing fiercely and endlessly, an epoch-making figure appears. Since ancient times, the theory of evolution with different opinions has finally formed an indisputable and convincing system in the hands of Darwin, a great British naturalist in the19th century. 1859 After Darwin's Origin of Species was published, the idea of universal evolution of organisms and the evolutionary mechanism of "natural selection, survival of the fittest" became public opinions in academic and ideological circles. Thus, Darwin's theory of biological evolution is called1one of the three great discoveries of natural science in the 9th century.
In the world-famous book Origin of Species, Darwin put forward one shocking conclusion after another: life has only one ancestor, because all life originated from the beginning of a primitive cell; Biology develops from simple to complex, from low to advanced. Biology is constantly experiencing survival competition and natural selection in evolution. ...
Darwin's Origin of Species has become a classic in the history of biology. Nowadays, many viewpoints mentioned in the Origin of Species have become well-known common sense. Darwin's theory of biological evolution has been continuously developed. In the early 1940s, Haldane, an Englishman, and Dubzhansky, a biologist from the United States and the Soviet Union, founded the "Modern Evolution Theory".
Modern evolutionists have abandoned Darwin's view that individuals are the basic units of biological evolution, and they believe that groups should be the basic units of evolution. Mutation itself is an adaptive trait of species, which is both the driving force and the result of evolution. The function of natural selection is not to select superior individuals, but to eliminate those who have no adaptability. Modern evolutionism explains many facts that classical Darwinism can't.
Unfortunately, in Darwin's time, Mendel, the pioneer of genetics, failed to convince the world of his genetic theory. Otherwise, Darwin would be in great pain, because in 1838, he chose his uncle's daughter and cousin Emma as his lifelong companion. It is said that Darwin heard a little about Mendel and his genetics in his later years, and he was often uneasy about consanguineous marriage. Darwin was buried next to the graves of Newton and John Herschel in Westminster Abbey, London, England.
[Edit this paragraph] charles robert darwin's famous saying
Category: Life
Optimism is a beacon of hope, guiding you from a dangerous canyon to a smooth road, giving you new life and new hope, and supporting your ideal forever.
Category: Time
A person who dares to waste even an hour shows that he still doesn't know how to cherish the full value of time.
The way to finish the work is to cherish every minute.
I never think that half an hour is insignificant time.
My life is as regular as a clock. When my life is over, I will stay in one place.
Category: thoughts
The shortening of life is in direct proportion to the waste of thought.
I have been trying to keep my thoughts free.
Category: reading
I have neither outstanding understanding nor extraordinary wit. It's just that my ability to perceive things that are fleeting and observe them carefully may be above ordinary people.
Category: true
The main reasons why I can become a scientist are: my love for science; Infinite patience to think about problems; Diligently observe and collect facts; A kind of creativity and rich common sense.
Any achievement I have made in science is only due to long-term thinking, patience and diligence.
Category: science
I can succeed in science, and the most important thing is my love for science and persistence in long-term exploration.
Ignorant people are more confident than knowledgeable people. Only the ignorant can confidently assert that science can never solve any problems.
Don't lose the ability to feel life, beauty and poetry because you have been immersed in science for a long time.
Any achievement I have made in science is only due to long-term thinking, patience and diligence.
As a scientist, my success ... mainly stems from my love for science-infinite patience for long-term thinking about any problem-diligence in observing and collecting facts-considerable invention ability and common sense.
The main reasons why I can become a scientist are: my love for science; Infinite patience to think about problems; Diligently observe and collect facts; A kind of creativity and rich common sense.
Science is to sort out facts in order to draw universal laws or conclusions from them.
Category: Ideal
Optimism is a beacon of hope, guiding you from a dangerous canyon to a smooth road, giving you new life and new hope, and supporting your ideal forever.
Category: Diligence
Any achievement I have made in science is only due to long-term thinking, patience and diligence.
If I have any advantages, it is not the result of my talent, but the result of diligence and perseverance.
Category: Work
The way to finish the work is to cherish every minute.
Category: Success
As a scientist, my success ... mainly stems from my love for science-infinite patience for long-term thinking about any problem-diligence in observing and collecting facts-considerable invention ability and common sense.
I can succeed in science, and the most important thing is my love for science and persistence in long-term exploration.
Category: friendship
When it comes to fame, honor, happiness and wealth, they are all dust if compared with friendship. ...
Category: protecting the environment
Only by obeying nature can we overcome nature.
[Edit this paragraph] chronology of major events
1809
On February 12, Charles Darwin was born in Shrewsbury, England.
18 17
Mom passed away.
18 17 ~ 1825
Studying in a private middle school in Shrewsbury.
1825 ~ 1827
Studying medicine at the University of Edinburgh in Scotland.
1828 ~ 183 1 year
Studying at Cambridge University in England.
183 1 year ~ 1836 years
Traveling around the world with the Beagle.
1837
Started writing the first note on species evolution.
1838
Read thomas malthus's Theory of Population.
1839
65438+ 10 month, married Emma Wedgwood; 65438+ February, son William was born; The first stage of a serious illness.
1839 ~ 1843
Compile a five-volume masterpiece "Beagle Fauna in Navigation"
1842
Moved to Davion House in the suburbs of London.
1842 ~ 1846
He wrote a three-volume book, Geology during the voyage of the Beagle.
1844
Writing unpublished evolutionary papers.
1846 ~ 1855
Research and write articles about barnacles.
1848
Father died; Poor health lasts for a long time. Daughter Anne passed away.
1855
Started writing the main works of evolution.
1858
Linnean society of london read Darwin's and Wallace's papers on evolution.
1859
Published the Origin of Species.
1860
The annual meeting of the British Association for the Advancement of Science held a big debate on evolution at Oxford University.
1863 ~ 1865
This situation continues.
1868
The variation of domestic animals and cultivated plants was published.
65438+70s, 09
Five books on plants have been published.
187 1 year
Published "Human Origin and Sexual Selection".
1872
Published "Expression of Human and Animal Emotions"
188 1 year
Publish a book about earthworms.
1882
19 April, Darwin died in Davenport; Buried in Westminster Abbey.
[Edit this paragraph] Darwin's funeral
1882 At 4 o'clock in the afternoon of April, Darwin stopped breathing in the arms of his wife Emma. Emma and her children set out to prepare for the funeral while sending obituaries to relatives and friends. Darwin's last wish was to be buried in the family cemetery in Dunn village, with his dead brother Erasmus and his eldest daughter Anne. His family and villagers also hope that he can rest in peace in the land where he has lived for more than 40 years.
However, some people think that Darwin's achievements should be given a state funeral and buried in Westminster Abbey, the pantheon of England. The next day, British newspapers published comments in succession, calling for the "greatest Englishman since Newton" to be buried with Newton and others for future generations to mourn. A newspaper also pointed out that as early as 15 years ago, the king of Prussia had awarded Darwin a knighthood, but the Queen of England did not, so that Darwin died as a civilian and could not be buried as a "knight". Shouldn't he make up for Britain's unfair treatment of his first son by paying homage? (Later, Darwin's three sons were successively knighted. Some newspapers also commented that Darwin belongs there more than many politicians who have been buried in Westminster Abbey, because "compared with the great impact of the achievements of this thinker who shocked the world, most of the daily political noise is just a dusty poverty." In the media appeal, the President of the Royal Society wrote to Darwin's family, asking them to allow Darwin to be buried in Westminster Abbey. John Rue Barker, Darwin's neighbor, President and Member of Parliament of Linnaeus Society, collected the signatures of 28 Members of Parliament and petitioned the Bishop of Westminster Abbey. The bishop of Westminster Abbey, who is visiting France, even received a petition from Parliament and sent a telegram saying that he agreed to let Darwin enter the church. The funeral was held on April 26th. Emma didn't attend the funeral and stayed at dawn's. Among the 10 pallbearers, there are not only Rubak and a priest from Westminster Abbey, but also the president of the Royal Society representing the scientific community, an earl and two dukes representing the government (one of them is the president of Darwin's alma mater, Cambridge University), the American ambassador representing foreign guests, and three of Darwin's closest friends who are still alive: botanist joseph hooker. Darwin secretly studied the theory of evolution for a long time after sailing around the world on the Beagle. Only some friends know that he is studying this theory that will subvert the world, and Hooke is one of them. Natural selection theory is the same as the discoverer Wallace. Darwin is going to publish his evolution manuscript after his death. As a peace-loving person, he doesn't want to see the controversy caused by the publication of this theory in society. But in the summer of 1858, I received a letter from Wallace, knowing that Wallace had independently discovered the theory of natural selection, which forced him to publish a paper on the theory of natural selection with Wallace at the same time after consulting Hooke and others, and published the Origin of Species the following year. Since then, the theory of natural selection has also been called Darwinism-this term was first used by Wallace. Paleontologist thomas huxley. Unsurprisingly, the publication of the Origin of Species caused an uproar. Darwin himself avoided participating in social debates, and Huxley fought everywhere instead of him to defend the theory of evolution, so he was awarded the title of "Darwin's dog fighting". Organizers include the mayor of London, members of the Royal Society, the Academy and other scientific societies, as well as representatives from all walks of life in various countries. Darwin was buried under Newton's tombstone in the hymn "Blessed are the people who get wisdom and wisdom".
No one thinks there is anything wrong with burying people who put forward theories that shocked the Christian world in the cathedral. The Times even commented: "The cathedral needs this funeral more than the cathedral." The conflict between evolution and Christianity seems to have become history. British Christian leaders took this opportunity to show their tolerance in front of the world. The Standard newspaper declared: "True Christians can accept the main scientific facts of evolution like astronomy and geology, and have no prejudice against older and more precious beliefs." "We can't appreciate all his theories, but we can admire his life," claimed Morning Post, a newspaper of an advanced missionary school. The Church Times simply said that Darwin was a "Christian gentleman". A few years later, rumors began to appear that Darwin gave up the theory of evolution in his last confession, which can still be seen in the propaganda materials of missionaries.
In fact, Darwin not only didn't believe in God when he died, but even hated Christianity. He didn't want to make public his religious stance before his death, on the one hand, because he didn't want to participate in disputes, and on the other hand, because he thought that atheism was only suitable for educated people, and the time for the general public to accept atheism was not yet mature. But privately, Darwin did not hide his opposition to Christianity. His autobiography written in his later years proves this point. In his autobiography, he used a chapter to talk about his beliefs, refuted all kinds of evidence about the existence of God, thought there was no reason to believe in the existence of God, and introduced the process of his spurning Christianity. He even criticized Christianity as a "cursed doctrine".